MCP1640/B/C/D

0.65V Start-Up Synchronous Boost Regulator

with True Output Disconnect or Input/Output Bypass Option

Features General Description

• Up to 96% Typical Efficiency The MCP1640/B/C/D is a compact, high-efficiency,
• 800 mA Typical Peak Input Current Limit: fixed frequency, synchronous step-up DC-DC con-
- IOUT > 100 mA @ 1.2V VIN, 3.3V VOUT verter. It provides an easy-to-use power supply solution
for applications powered by either single-cell, two-cell,
- IOUT > 350 mA @ 2.4V VIN, 3.3V VOUT
or three-cell alkaline, NiCd, NiMH, and single-cell Li-Ion
- IOUT > 350 mA @ 3.3V VIN, 5.0V VOUT or Li-Polymer batteries.
• Low Start-Up Voltage: 0.65V, typical 3.3V VOUT
Low-voltage technology allows the regulator to start-up
@ 1 mA
without high inrush current or output voltage overshoot
• Low Operating Input Voltage: 0.35V, typical from a low 0.65V input. High efficiency is accomplished
3.3VOUT @ 1 mA by integrating the low resistance N-Channel Boost
• Adjustable Output Voltage Range: 2.0V to 5.5V switch and synchronous P-Channel switch. All
• Maximum Input Voltage  VOUT < 5.5V compensation and protection circuitry is integrated to
• Automatic PFM/PWM Operation (MCP1640/C): minimize the number of external components. For
standby applications, the MCP1640 consumes only
- PFM Operation Disabled (MCP1640B/D)
19 µA while operating at no load, and provides a true
- PWM Operation: 500 kHz disconnect from input to output while in Shutdown
• Low Device Quiescent Current: 19 µA, typical (EN = GND). Additional device options are available by
PFM Mode (not switching) operating in PWM-Only mode and connecting input to
• Internal Synchronous Rectifier output while the device is in Shutdown.
• Internal Compensation The “true” load disconnect mode provides input-to-out-
• Inrush Current Limiting and Internal Soft Start put isolation while the device is disabled by removing
• Selectable, Logic Controlled Shutdown States: the normal boost regulator diode path from input-to-
- True Load Disconnect Option (MCP1640/B) output. The Input-to-Output Bypass mode option con-
nects the input to the output using the integrated low
- Input to Output Bypass Option (MCP1640C/D)
resistance P-Channel MOSFET, which provides a low
• Shutdown Current (All States): < 1 µA bias voltage for circuits operating in Deep Sleep mode.
• Low Noise, Anti-Ringing Control Both options consume less than 1 µA of input current.
• Overtemperature Protection Output voltage is set by a small external resistor
• Available Packages: divider. Two package options are available, 6-Lead
- 6-Lead SOT-23 SOT-23 and 8-Lead 2 x 3 mm DFN.
- 8-Lead 2 x 3 mm DFN
Package Types
Applications MCP1640 MCP1640
• One, Two and Three Cell Alkaline and NiMH/NiCd 6-Lead SOT-23 8-Lead 2 x 3 DFN*
Portable Products
• Single-Cell Li-Ion to 5V Converters SW 1 6 VIN VFB 1 8 VIN
• Li Coin Cell Powered Devices GND 2 5 VOUT
SGND 2 EP 7 VOUTS
• Personal Medical Products PGND 3 9
6 VOUTP
EN 3 4 VFB
• Wireless Sensors EN 4 5 SW
• Handheld Instruments
• GPS Receivers * Includes Exposed Thermal Pad (EP); see Table 3-1.
• Bluetooth Headsets
• +3.3V to +5.0V Distributed Power Supply

 2010-2015 Microchip Technology Inc. DS20002234D-page 1

MCP1640/B/C/D
Typical Application

L1
4.7 µH

VOUT
VIN 3.3V @ 100 mA
SW V
0.9V to 1.7V OUT
VIN
976 k
CIN COUT
+
4.7 µF EN VFB 10 µF
ALKALINE

562 k

- GND

L1
4.7 µH

VOUT
VIN 5.0V @ 300 mA
SW V
3.0V to 4.2V OUTS
VIN VOUTP 976 k
CIN COUT
+
4.7 µF EN VFB 10 µF
LI-ION

309 k
- PGND SGND

Efficiency vs. IOUT for 3.3VOUT

100.0
V IN = 2.5V
Efficiency (%)

80.0

V IN = 0.8V V IN = 1.2V
60.0

40.0
0.1 1.0 10.0 100.0 1000.0
Output Current (mA)

DS20002234D-page 2  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
1.0 ELECTRICAL † Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device.
CHARACTERISTICS This is a stress rating only and functional operation of
the device at those or any other conditions above those
Absolute Maximum Ratings † indicated in the operational sections of this
EN, VFB, VIN, VSW, VOUT - GND ......................... +6.5V specification is not intended. Exposure to maximum
rating conditions for extended periods may affect
EN, VFB ....<maximum of VOUT or VIN > (GND – 0.3V)
device reliability.
Output Short-Circuit Current ...................... Continuous
Output Current Bypass Mode........................... 400 mA
Power Dissipation ............................ Internally Limited
Storage Temperature ......................... -65°C to +150°C
Ambient Temp. with Power Applied...... -40°C to +85°C
Operating Junction Temperature........ -40°C to +125°C
ESD Protection On All Pins:
HBM........................................................ 3 kV
MM......................................................... 300V

DC CHARACTERISTICS
Electrical Characteristics: Unless otherwise indicated, VIN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V,
IOUT = 15 mA, TA = +25°C. Boldface specifications apply over the TA range of -40°C to +85°C.
Parameters Sym. Min. Typ. Max. Units Conditions
Input Characteristics
Minimum Start-Up Voltage VIN — 0.65 0.8 V Note 1
Minimum Input Voltage After VIN — 0.35 — V Note 1
Start-Up
Output Voltage Adjust Range VOUT 2.0 5.5 V VOUT  VIN; Note 2
Maximum Output Current IOUT — 150 — mA 1.2V VIN, 2.0V VOUT
— 150 — mA 1.5V VIN, 3.3V VOUT
— 350 — mA 3.3V VIN, 5.0V VOUT
Feedback Voltage VFB 1.175 1.21 1.245 V
Feedback Input Bias Current IVFB — 10 — pA
Quiescent Current – PFM IQPFM — 19 30 µA Measured at VOUT = 4.0V;
Mode EN = VIN, IOUT = 0 mA;
Note 3
Quiescent Current – PWM IQPWM — 220 — µA Measured at VOUT = 4.0V;
Mode EN = VIN, IOUT = 0 mA;
Note 3
Quiescent Current – Shutdown IQSHDN — 0.7 2.3 µA VOUT = EN = GND;
Includes N-Channel and
P-Channel Switch Leakage
NMOS Switch Leakage INLK — 0.3 — µA VIN = VSW = 5V;
VOUT = 5.5V
VEN = VFB = GND
PMOS Switch Leakage IPLK — 0.05 — µA VIN = VSW = GND;
VOUT = 5.5V
Note 1: 3.3 k resistive load, 3.3VOUT (1 mA).
2: For VIN > VOUT, VOUT will not remain in regulation.
3: IQOUT is measured at VOUT; VOUT is externally supplied with a voltage higher than the nominal 3.3V output
(device is not switching); no load; VIN quiescent current will vary with boost ratio. VIN quiescent current
can be estimated by: (IQPFM * (VOUT/VIN)), (IQPWM * (VOUT/VIN)).
4: Peak current limit determined by characterization, not production tested.
5: 220 resistive load, 3.3VOUT (15 mA).

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MCP1640/B/C/D
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: Unless otherwise indicated, VIN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V,
IOUT = 15 mA, TA = +25°C. Boldface specifications apply over the TA range of -40°C to +85°C.
Parameters Sym. Min. Typ. Max. Units Conditions
NMOS Switch On Resistance RDS(ON)N — 0.6 —  VIN = 3.3V, ISW = 100 mA
PMOS Switch On Resistance RDS(ON)P — 0.9 —  VIN = 3.3V, ISW = 100 mA
NMOS Peak Switch Current IN(MAX) 600 850 — mA Note 4
Limit
VOUT Accuracy VOUT% -3 — +3 % Includes Line and Load
Regulation; VIN = 1.5V
Line Regulation VOUT/VOUT) -1 0.01 1 %/V VIN = 1.5V to 3V
/VIN| IOUT = 25 mA
Load Regulation VOUT/VOUT| -1 0.01 1 % IOUT = 25 mA to 100 mA;
VIN = 1.5V
Maximum Duty Cycle DCMAX 88 90 — %
Switching Frequency fSW 425 500 575 kHz
EN Input Logic High VIH 90 — — %of VIN IOUT = 1 mA
EN Input Logic Low VIL — — 20 %of VIN IOUT = 1 mA
EN Input Leakage Current IENLK — 0.005 — µA VEN = 5V
Soft-Start Time tSS — 750 — µS EN Low-to-High,
90% of VOUT; Note 5
Thermal Shutdown Die TSD — 150 — C
Temperature
Die Temperature Hysteresis TSDHYS — 10 — C
Note 1: 3.3 k resistive load, 3.3VOUT (1 mA).
2: For VIN > VOUT, VOUT will not remain in regulation.
3: IQOUT is measured at VOUT; VOUT is externally supplied with a voltage higher than the nominal 3.3V output
(device is not switching); no load; VIN quiescent current will vary with boost ratio. VIN quiescent current
can be estimated by: (IQPFM * (VOUT/VIN)), (IQPWM * (VOUT/VIN)).
4: Peak current limit determined by characterization, not production tested.
5: 220 resistive load, 3.3VOUT (15 mA).

TEMPERATURE SPECIFICATIONS
Electrical Specifications: Unless otherwise indicated, VIN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V, IOUT = 15 mA.
Parameters Sym. Min. Typ. Max. Units Conditions
Temperature Ranges
Operating Junction Temperature TJ -40 — +125 °C Steady State
Range
Storage Temperature Range TA -65 — +150 °C
Maximum Junction Temperature TJ — — +150 °C Transient
Package Thermal Resistances
Thermal Resistance, 6LD-SOT-23 JA — 190.5 — °C/W
Thermal Resistance, 8LD-2x3 DFN JA — 75 — °C/W

DS20002234D-page 4  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
2.0 TYPICAL PERFORMANCE CURVES
Note: The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.

Note: Unless otherwise indicated, VIN = EN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V, ILOAD = 15 mA, TA = +25°C.

27.5 100
VIN = 1.2V VOUT = 2.0V VIN = 1.6V
25.0 VOUT = 5.0V 90
80
IQ PFM Mode (µA)

22.5

Efficiency (%)
70 VIN = 0.8V

20.0 60
VIN = 1.2V
50
17.5 VOUT = 3.3V
40
15.0 VOUT = 2.0V 30
20
12.5 PWM / PFM
10
PWM Only
10.0 0
-40 -25 -10 5 20 35 50 65 80 0.01 0.1 1 10 100 1000
Ambient Temperature (°C) IOUT (mA)

FIGURE 2-1: VOUT IQ vs. Ambient FIGURE 2-4: 2.0V VOUT PFM/PWM Mode
Temperature in PFM Mode. Efficiency vs. IOUT.

300 100
VOUT = 3.3V VIN = 2.5V
VIN = 1.2V 90
275 VOUT = 5.0V
80
IQ PWM Mode (µA)

Efficiency (%)

70 VIN = 0.8V
250
60 VIN = 1.2V

225 VOUT = 3.3V 50

40
200
30
175 20
PWM / PFM
10
PWM Only
150 0
-40 -25 -10 5 20 35 50 65 80 0.01 0.1 1 10 100 1000
Ambient Temperature (°C) IOUT (mA)

FIGURE 2-2: VOUT IQ vs. Ambient FIGURE 2-5: 3.3V VOUT PFM/PWM Mode
Temperature in PWM Mode. Efficiency vs. IOUT.

600 100
VOUT = 5.0V VIN = 3.6V
VOUT = 5.0V 90
500 VOUT = 3.3V 80
Efficiency (%)

70 VIN = 1.2V VIN = 1.8V

400
IOUT (mA)

60
VOUT = 2.0V
300 50
40
200
30
100 20
PWM / PFM
10 PWM Only
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0
0.01 0.1 1 10 100 1000
VIN (V) IOUT (mA)

FIGURE 2-3: Maximum IOUT vs. VIN After FIGURE 2-6: 5.0V VOUT PFM/PWM Mode
Start-Up, VOUT 10% Below Regulation Point. Efficiency vs. IOUT.

 2010-2015 Microchip Technology Inc. DS20002234D-page 5

MCP1640/B/C/D
Note: Unless otherwise indicated, VIN = EN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V, ILOAD = 15 mA, TA = +25°C.

3.33 1.00
IOUT = 15 mA VIN = 1.2V VOUT = 3.3V
3.325
3.32 0.85
VIN = 1.8V
3.315 Startup
VOUT (V)

VIN (V)
0.70
3.31
3.305
0.55
3.3 VIN = 0.8V Shutdown

3.295 0.40
3.29
3.285 0.25
-40 -25 -10 5 20 35 50 65 80 0 20 40 60 80 100
Ambient Temperature (°C) IOUT (mA)

FIGURE 2-7: 3.3V VOUT vs. Ambient FIGURE 2-10: Minimum Start-Up and
Temperature. Shutdown VIN into Resistive Load vs. IOUT.

3.38 525
VIN = 1.5V VOUT = 3.3V

Switching Frequency (kHz)

520
3.36
515
3.34 510
VOUT (V)

IOUT = 5 mA
505
3.32
500
3.30 495
IOUT = 15 mA
490
3.28 IOUT = 50 mA
485
3.26 480
-40 -25 -10 5 20 35 50 65 80 -40 -25 -10 5 20 35 50 65 80
Ambient Temperature (°C) Ambient Temperature (°C)

FIGURE 2-8: 3.3V VOUT vs. Ambient FIGURE 2-11: FOSC vs. Ambient
Temperature. Temperature.

3.40 4.5
IOUT = 5 mA
TA = +85°C 4 VOUT = 5.0V
3.36 3.5

TA = +25°C 3
VOUT (V)

VOUT = 3.3V
VIN (V)

3.32 2.5
2 VOUT = 2.0V
3.28 TA = -40°C
1.5
1
3.24
0.5
3.20 0
0.8 1.2 1.6 2 2.4 2.8 0 1 2 3 4 5 6 7 8 9 10
VIN (V) IOUT (mA)

FIGURE 2-9: 3.3V VOUT vs. VIN. FIGURE 2-12: PWM Pulse-Skipping Mode
Threshold vs. IOUT.

DS20002234D-page 6  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
Note: Unless otherwise indicated, VIN = EN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V, ILOAD = 15 mA, TA = +25°C.

10000
PWM / PFM
PWM Only

1000 VOUT = 5.0V

IIN (µA)

VOUT = 3.3V
VOUT = 2.0V

100

VOUT = 5.0V
VOUT = 2.0V VOUT = 3.3V

10
0.8 1.1 1.4 1.7 2 2.3 2.6 2.9 3.2 3.5
VIN (V)

FIGURE 2-13: Input No Load Current vs. FIGURE 2-16: MCP1640 3.3V VOUT PFM
VIN. Mode Waveforms.

5
IOUT = 1 mA
Switch Resistance (Ohms)

VOUT
4 20 mV/DIV
AC
P - Channel Coupled

3
VSW
2V/DIV

1
IL
0.05 mA/DIV
N - Channel
0
1 1.5 2 2.5 3 3.5 4 4.5 5 1 µs/DIV
> VIN or VOUT

FIGURE 2-14: N-Channel and P-Channel FIGURE 2-17: MCP1640B 3.3V VOUT
RDSON vs. > of VIN or VOUT. PWM Mode Waveforms.

60

50 VOUT = 3.3V VOUT = 5.0V

40
IOUT (mA)

VOUT = 2.0V
30

20

10

0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
VIN (V)

FIGURE 2-15: Average of PFM/PWM FIGURE 2-18: MCP1640/B High Load

Threshold Current vs. VIN. Waveforms.

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MCP1640/B/C/D
Note: Unless otherwise indicated, VIN = EN = 1.2V, COUT = CIN = 10 µF, L = 4.7 µH, VOUT = 3.3V, ILOAD = 15 mA, TA = +25°C.

MCP1640B PWM
Mode Only
VOUT
100 mV/DIV
VOUT AC
1V/DIV Coupled

ISTEP = 1 mA to 75 mA

VIN
1V/DIV IOUT
50 mA/DIV
VEN
1V/DIV

500 µs/DIV 100 µs/DIV

FIGURE 2-19: 3.3V Start-Up After Enable. FIGURE 2-22: MCP1640B 3.3V VOUT Load
Transient Waveforms.

MCP1640B PWM
Mode Only

VOUT
1V/DIV
VOUT
50 mV/DIV
AC
Coupled
ISTEP = 1 mA to 50 mA
VIN
1V/DIV
IOUT
VEN 50 mA/DIV
1V/DIV

500 µs/DIV 100 µs/DIV

FIGURE 2-20: 3.3V Start-Up when FIGURE 2-23: MCP1640B 2.0V VOUT Load
VIN = VENABLE. Transient Waveforms.

PFM
PWM MODE
MODE
VOUT
VOUT 50 mV/DIV
100 mV/DIV AC
AC Coupled
Coupled

ISTEP = 1 mA to 75 mA

VIN VSTEP from

IOUT
1V/DIV 1V to 2.5V
50 mA/DIV

100 µs/DIV 200 µs/DIV

FIGURE 2-21: MCP1640 3.3V VOUT Load FIGURE 2-24: 3.3V VOUT Line Transient
Transient Waveforms. Waveforms.

DS20002234D-page 8  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.

TABLE 3-1: PIN FUNCTION TABLE

MCP1640/B/C/D MCP1640/B/C/D
Symbol Description
2x3 DFN SOT-23
1 4 VFB Feedback Voltage Pin
2 — SGND Signal Ground Pin
3 — PGND Power Ground Pin
4 3 EN Enable Control Input Pin
5 1 SW Switch Node, Boost Inductor Input Pin
6 — VOUTP Output Voltage Power Pin
7 — VOUTS Output Voltage Sense Pin
8 6 VIN Input Voltage Pin
9 — EP Exposed Thermal Pad (EP); must be connected to VSS
— 2 GND Ground Pin
— 5 VOUT Output Voltage Pin

3.1 Feedback Voltage Pin (VFB) 3.6 Output Voltage Power Pin (VOUTP)
The VFB pin is used to provide output voltage regulation The output voltage power pin connects the output
by using a resistor divider. Feedback voltage will be voltage to the switch node. High current flows through
1.21V typical with the output voltage in regulation. the integrated P-Channel and out of this pin to the
output capacitor and the output. In the 2x3 DFN
package, VOUTP and VOUTS are connected externally.
3.2 Signal Ground Pin (SGND)
The signal ground pin is used as a return for the
3.7 Output Voltage Sense Pin (VOUTS)
integrated VREF and error amplifier. In the 2x3 DFN The output voltage sense pin connects the regulated
package, the SGND and power ground (PGND) pins are output voltage to the internal bias circuits. In the
connected externally. 2x3 DFN package, the VOUTS and output voltage
power (VOUTP) pins are connected externally.
3.3 Power Ground Pin (PGND)
3.8 Power Supply Input Voltage Pin (VIN)
The power ground pin is used as a return for the
Connect the input voltage source to VIN. The input
high-current N-Channel switch. In the 2x3 DFN
source should be decoupled to GND with a 4.7 µF
package, the PGND and SGND pins are connected
minimum capacitor.
externally.
3.9 Exposed Thermal Pad (EP)
3.4 Enable Pin (EN) There is no internal electrical connection between the
The EN pin is a logic-level input used to enable or Exposed Thermal Pad (EP) and the SGND and PGND
disable device switching and lower quiescent current pins. They must be connected to the same potential on
while disabled. A logic high (>90% of VIN) will enable the Printed Circuit Board (PCB).
the regulator output. A logic low (<20% of VIN) will
ensure that the regulator is disabled.
3.10 Ground Pin (GND)
The ground or return pin is used for circuit ground
3.5 Switch Node Pin (SW) connection. Length of trace from input cap return,
output cap return, and GND pin should be made as
Connect the inductor from the input voltage to the SW short as possible to minimize noise on the GND pin. In
pin. The SW pin carries inductor current and can be as the SOT-23-6 package, a single ground pin is used.
high as 800 mA peak. The integrated N-Channel switch
drain and integrated P-Channel switch source are 3.11 Output Voltage Pin (VOUT)
internally connected at the SW node.
The output voltage pin connects the integrated
P-Channel MOSFET to the output capacitor. The FB
voltage divider is also connected to the VOUT pin for
voltage regulation.

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MCP1640/B/C/D
NOTES:

DS20002234D-page 10  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
4.0 DETAILED DESCRIPTION For noise immunity, the N-Channel MOSFET current
sense is blanked for approximately 100 ns. With a typ-
ical minimum duty cycle of 100 ns, the MCP1640B/D
4.1 Device Option Overview
continues to switch at a constant frequency under light
The MCP1640/B/C/D family of devices is capable of load conditions. Figure 2-12 represents the input volt-
low start-up voltage and delivers high efficiency over a age versus load current for the pulse skipping threshold
wide load range for single-cell, two-cell, or three-cell in PWM-Only mode. At lighter loads, the MCP1640B/D
alkaline, NiCd, NiMH and single-cell Li-Ion battery devices begin to skip pulses.
inputs. A high level of integration lowers total system
cost, eases implementation and reduces board area. 4.1.3 TRUE OUTPUT DISCONNECT
MODE OPTION
The devices feature low start-up voltage, adjustable
output voltage, PWM/PFM mode operation, low IQ, The MCP1640/B devices incorporate a true output
integrated synchronous switch, internal compensation, disconnect feature. With the EN pin pulled low, the
low noise anti-ring control, inrush current limit, and soft output of the MCP1640/B is isolated or disconnected
start. from the input by turning off the integrated P-Channel
switch and removing the switch bulk diode connection.
There are two options for the MCP1640/B/C/D family:
This removes the DC path that is typical in boost con-
• PWM/PFM mode or PWM-Only mode verters, which allows the output to be disconnected
• “True Output Disconnect” mode or Input-to-Output from the input. During this mode, less than 1 µA of cur-
Bypass mode rent is consumed from the input (battery). True output
disconnect does not discharge the output; the output
4.1.1 PWM/PFM MODE OPTION voltage is held up by the external COUT capacitance.
The MCP1640/C devices use an automatic switchover
from PWM to PFM mode for light load conditions to 4.1.4 INPUT BYPASS MODE OPTION
maximize efficiency over a wide range of output The MCP1640C/D devices incorporate the Input
current. During PFM mode, higher peak current is used Bypass shutdown option. With the EN input pulled low,
to pump the output up to the threshold limit. While the output is connected to the input using the internal
operating in PFM or PWM mode, the P-Channel switch P-Channel MOSFET. In this mode, the current draw
is used as a synchronous rectifier, turning off when the from the input (battery) is less than 1 µA with no load.
inductor current reaches 0 mA to maximize efficiency. Input Bypass mode is used when the input voltage
In PFM mode, a comparator is used to terminate range is high enough for the load to operate in Sleep or
switching when the output voltage reaches the upper Low IQ mode. When a higher regulated output voltage
threshold limit. Once switching has terminated, the is necessary to operate the application, the EN input is
output voltage will decay or coast down. During this pulled high, enabling the boost converter.
period, very low IQ is consumed from the device and
TABLE 4-1: PART NUMBER SELECTION
input source, which keeps power efficiency high at light
load. Input
Part PWM/ PWM True -to-
The disadvantages of PWM/PFM mode are higher out-
Number PFM -Only Disconnect Output
put ripple voltage and variable PFM mode frequency.
Bypass
The PFM mode frequency is a function of input voltage,
output voltage and load. While in PFM mode, the boost MCP1640 X X
converter pumps the output up at a switching frequency MCP1640B X X
of 500 kHz.
MCP1640C X X
4.1.2 PWM-ONLY MODE OPTION MCP1640D X X
The MCP1640B/D devices disable PFM mode
switching, and operate only in PWM mode over the
entire load range. During periods of light load opera-
tion, the MCP1640B/D continues to operate at a con-
stant 500 kHz switching frequency, keeping the output
ripple voltage lower than PFM mode.
During PWM-Only mode, the MCP1640B/D P-Channel
switch acts as a synchronous rectifier by turning off (to
prevent reverse current flow from the output cap back
to the input) in order to keep efficiency high.

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MCP1640/B/C/D
4.2 Functional Description Figure 4-1 depicts the functional block diagram of the
MCP1640/B/C/D.
The MCP1640/B/C/D is a compact, high-efficiency,
fixed frequency, step-up DC-DC converter that
provides an easy-to-use power supply solution for
applications powered by either single-cell, two-cell, or
three-cell alkaline, NiCd, NiMH, and single-cell Li-Ion or
Li-Polymer batteries.

VOUT

Internal
VIN
Bias
IZERO

Direction
Control

SW Soft Start
.3V
0V
Gate Drive ILIMIT
and
EN Shutdown
Control
Logic
ISENSE

Slope
GND Oscillator
Comp.
S

PWM/PFM
Logic

1.21V
FB
EA

FIGURE 4-1: MCP1640/B/C/D Block Diagram.

4.2.1 LOW-VOLTAGE START-UP current is limited to 50% of its nominal value. Once the
The MCP1640/B/C/D is capable of starting from a low output voltage reaches 1.6V, normal closed-loop PWM
input voltage. Start-up voltage is typically 0.65V for a operation is initiated.
3.3V output and 1 mA resistive load. The MCP1640/B/C/D charges an internal capacitor
When enabled, the internal start-up logic turns the with a very weak current source. The voltage on this
rectifying P-Channel switch on until the output capacitor, in turn, slowly ramps the current limit of the
capacitor is charged to a value close to the input boost switch to its nominal value. The soft-start
voltage. The rectifying switch is current-limited to capacitor is completely discharged in the event of a
approximately 100 mA during this time. This will affect commanded shutdown or a thermal shutdown.
the start-up under higher load currents, and the device There is no undervoltage lockout feature for the
may not start to the nominal value. After charging the MCP1640/B/C/D. The device will start-up at the lowest
output capacitor to the input voltage, the device starts possible voltage and run down to the lowest possible
switching. If the input voltage is below 1.6V, the device voltage. For typical battery applications, this may result
runs open-loop with a fixed duty cycle of 70% until the in “motor-boating” (emitting a low-frequency tone) for
output reaches 1.6V. During this time, the boost switch deeply discharged batteries.

DS20002234D-page 12  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
4.2.2 PWM-ONLY MODE OPERATION 4.2.5 ENABLE PIN
In normal PWM operation, the MCP1640/B/C/D The enable pin is used to turn the boost converter on
operates as a fixed frequency, synchronous boost and off. The enable threshold voltage varies with input
converter. The switching frequency is internally voltage. To enable the boost converter, the EN voltage
maintained with a precision oscillator typically set to level must be greater than 90% of the VIN voltage. To
500 kHz. The MCP1640B/D devices will operate in disable the boost converter, the EN voltage must be
PWM-Only mode even during periods of light load less than 20% of the VIN voltage.
operation. By operating in PWM-Only mode, the output
ripple remains low and the frequency is constant. 4.2.6 INTERNAL BIAS
Operating in fixed PWM mode results in lower The MCP1640/B/C/D gets its start-up bias from VIN.
efficiency during light load operation (when compared Once the output exceeds the input, bias comes from
to PFM mode (MCP1640/C)). the output. Therefore, once started, operation is
Lossless current sensing converts the peak current sig- completely independent of VIN. Operation is only
nal to a voltage to sum with the internal slope compen- limited by the output power level and the input source
sation. This summed signal is compared to the voltage series resistance. When started, the output will remain
error amplifier output to provide a peak current control in regulation down to 0.35V typical with 1 mA output
command for the PWM signal. The slope current for low source impedance inputs.
compensation is adaptive to the input and output
voltage. Therefore, the converter provides the proper 4.2.7 INTERNAL COMPENSATION
amount of slope compensation to ensure stability, but is The error amplifier, with its associated compensation
not excessive, which causes a loss of phase margin. network, completes the closed-loop system by
The peak current limit is set to 800 mA typical. comparing the output voltage to a reference at the
input of the error amplifier, and feeding the amplified
4.2.3 PFM MODE OPERATION and inverted signal to the control input of the inner
The MCP1640/C devices are capable of operating in current loop. The compensation network provides
normal PWM mode and PFM mode to maintain high phase leads and lags at appropriate frequencies to
efficiency at all loads. In PFM mode, the output ripple cancel excessive phase lags and leads of the power
has a variable frequency component that changes with circuit. All necessary compensation components and
the input voltage and output current. The value of the slope compensation are integrated.
output capacitor changes the low-frequency compo-
nent ripple. Output ripple peak-to-peak values are not 4.2.8 SHORT CIRCUIT PROTECTION
affected by the output capacitor. With no load, the qui- Unlike most boost converters, the MCP1640/B/C/D
escent current draw from the output is typically 19 µA. allows its output to be shorted during normal operation.
This is not a switching current and is not dependent on The internal current limit and overtemperature
the input and output parameters. The no-load input cur- protection limit excessive stress and protect the device
rent drawn from the battery depends on the above during periods of short circuit, overcurrent and over-
parameters. Its variation is shown in Figure 2-13. The temperature. While operating in Bypass mode, the
PFM mode can be disabled in selected device options. P-Channel current limit is inhibited to minimize
PFM operation is initiated if the output load current falls quiescent current.
below an internally programmed threshold. The output
voltage is continuously monitored. When the output 4.2.9 LOW NOISE OPERATION
voltage drops below its nominal value, PFM operation The MCP1640/B/C/D integrates a low noise anti-ring
pulses one or several times to bring the output back switch that damps the oscillations typically observed at
into regulation. If the output load current rises above the switch node of a boost converter when operating in
the upper threshold, the MCP1640/C transitions the Discontinuous Inductor Current mode. This
smoothly into PWM mode. removes the high-frequency radiated noise.

4.2.4 ADJUSTABLE OUTPUT VOLTAGE 4.2.10 OVERTEMPERATURE

The MCP1640/B/C/D output voltage is adjustable with PROTECTION
a resistor divider over a 2.0V minimum to 5.5V Overtemperature protection circuitry is integrated into
maximum range. High-value resistors can be used to the MCP1640/B/C/D. This circuitry monitors the device
minimize quiescent current to keep efficiency high at junction temperature and shuts the device off if the
light loads. junction temperature exceeds the typical +150°C
threshold. If this threshold is exceeded, the device will
automatically restart when the junction temperature
drops by 10°C. The soft start is reset during an
overtemperature condition.

 2010-2015 Microchip Technology Inc. DS20002234D-page 13

MCP1640/B/C/D
NOTES:

DS20002234D-page 14  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
5.0 APPLICATION INFORMATION For boost converters, the removal of the feedback
resistors during operation must be avoided. In this
case, the output voltage will increase above the
5.1 Typical Applications
absolute maximum output limits of the MCP1640/B/C/D
The MCP1640/B/C/D synchronous boost regulator and damage the device.
operates over a wide input and output voltage range. The maximum device output current is dependent upon
The power efficiency is high for several decades of load the input and output voltage. For example, to ensure a
range. Output current capability increases with input 100 mA load current for VOUT = 3.3V, a minimum of
voltage and decreases with increasing output voltage. 1.0-1.1V input voltage is necessary. If an application is
The maximum output current is based on the powered by one Li-Ion battery (VIN from 3.0V to 4.2V),
N-Channel peak current limit. Typical characterization the minimum load current the MCP1640/B/C/D can
curves in this data sheet are presented to display the deliver is close to 300 mA at 5.0V output and a
typical output current capability. maximum of 500 mA (Figure 2-3).

5.2 Adjustable Output Voltage 5.2.1 VIN > VOUT SITUATION

Calculations and For VIN > VOUT, the output voltage will not remain in
Maximum Output Current regulation. VIN > VOUT is an unusual situation for a
boost converter, and there is a common issue when
To calculate the resistor divider values for the two Alkaline cells (2 x 1.6V typical) are used to boost to
MCP1640/B/C/D, the following equation can be used, 3.0V output. The Input-to-Output Bypass option is
where RTOP is connected to VOUT, RBOT is connected recommended to be used in this situation until the
to GND and both are connected to the FB input pin. batteries’ voltages go down to a safe headroom. A
minimum headroom of approximately 150 to 200 mV
EQUATION 5-1: between VOUT and VIN must be ensured, unless a low-
frequency, high-amplitude output ripple on VOUT is
 V OUT  expected. The ripple and its frequency is VIN and load
R TOP = RBOT   ---------------- – 1
 V FB  dependent. The higher the VIN, the higher the ripple
and the lower its frequency.

EXAMPLE 1: 5.3 Input Capacitor Selection

VOUT = 3.3V The boost input current is smoothed by the boost induc-
VFB = 1.21V tor reducing the amount of filtering necessary at the
input. Some capacitance is recommended to provide
RBOT = 309 k
decoupling from the source. Low ESR X5R or X7R are
RTOP = 533.7 k (Standard Value = 536 k) well suited since they have a low temperature coefficient
and small size. For most applications, 4.7 µF of capaci-
EXAMPLE 2: tance is sufficient at the input. For high-power applica-
tions that have high source impedance or long leads,
VOUT = 5.0V connecting the battery to the input 10 µF of capacitance
VFB = 1.21V is recommended. Additional input capacitance can be
RBOT = 309 k added to provide a stable input voltage.
RTOP = 967.9 k (Standard Value = 976 k) Table 5-1 contains the recommended range for the
input capacitor value.
The internal error amplifier is of transconductance type; its
gain is not related to the resistors' value. There are some 5.4 Output Capacitor Selection
potential issues with higher-value resistors. For small
surface-mount resistors, environment contamination can The output capacitor helps provide a stable output
create leakage paths that significantly change the resistor voltage during sudden load transients and reduces the
divider ratio and modify the output voltage tolerance. output voltage ripple. As with the input capacitor, X5R
and X7R ceramic capacitors are well suited for this appli-
Smaller feedback resistor values will increase the
cation. Using other capacitor types (aluminum or tanta-
current drained from the battery by a few µA, but will
lum) with large ESR has an impact on the converter's
result in good regulation over the entire temperature
efficiency and maximum output power (see AN1337).
range and environment conditions. The feedback input
leakage current can also impact the divider and change
the output voltage tolerance.

 2010-2015 Microchip Technology Inc. DS20002234D-page 15

MCP1640/B/C/D
The MCP1640/B/C/D is internally compensated, so 5.5 Inductor Selection
output capacitance range is limited (see Table 5-1 for
The MCP1640/B/C/D is designed to be used with small
the recommended output capacitor range). An output
surface-mount inductors; the inductance value can
capacitance higher than 10 µF adds a better load-step
range from 2.2 µH to 10 µH. An inductance value of
response and high-frequency noise attenuation, espe-
4.7 µH is recommended to achieve a good balance
cially while stepping from light current loads (PFM
between inductor size, converter load transient
mode) to heavy current loads (PWM mode). Over-
response and minimized noise.
shoots and undershoots during pulse load application
are reduced by adding a zero in the compensation TABLE 5-2: MCP1640/B/C/D
loop. A small capacitance (for example 100 pF) in par-
RECOMMENDED INDUCTORS
allel with an upper feedback resistor will reduce output

 (typ.)
spikes, especially in PFM mode. Size

Value

DCR
(µH)

ISAT
(A)
Part Number WxLxH
While the N-Channel switch is on, the output current is
(mm)
supplied by the output capacitor COUT. The amount of
output capacitance and equivalent series resistance Coilcraft
will have a significant effect on the output ripple EPL2014-472 4.7 0.23 1.06 2.0x2.0x1.4
voltage. While COUT provides load current, a voltage EPL3012-472 4.7 0.165 1.1 3.0x3.0x1.3
drop also appears across its internal ESR that results
MSS4020-472 4.7 0.115 1.5 4.0x4.0x2.0
in ripple voltage.
LPS6225-472 4.7 0.065 3.2 6.0x6.0x2.4
EQUATION 5-2: Coiltronics®
SD3110 4.7 0.285 0.68 3.1x3.1x1.0
I OUT = COUT   -------
dV
dt SD3112 4.7 0.246 0.80 3.1x3.1x1.2
Where: SD3114 4.7 0.251 1.14 3.1x3.1x1.4
dV = ripple voltage SD3118 4.7 0.162 1.31 3.8x3.8x1.2

dt = On time of the N-Channel switch SD3812 4.7 0.256 1.13 3.8x3.8x1.2

(D x 1/FSW) SD25 4.7 0.0467 1.83 5.0x5.0x2.5
Würth Elektronik®
Table 5-1 contains the recommended range for the WE-TPC Type TH 4.7 0.200 0.8 2.8x2.8x1.35
input and output capacitor value. WE-TPC Type S 4.7 0.105 0.90 3.8x3.8x1.65
TABLE 5-1: CAPACITOR VALUE RANGE WE-TPC Type M 4.7 0.082 1.65 4.8x4.8x1.8
WE-TPC Type X 4.7 0.046 2.00 6.8x6.8x2.3
CIN COUT
Sumida Corporation
Min. 4.7 µF 10 µF
CMH23 4.7 0.537 0.70 2.3x2.3x1.0
Max. — 100 µF
CMD4D06 4.7 0.216 0.75 3.5x4.3x0.8
CDRH4D 4.7 0.09 0.800 4.6x4.6x1.5
TDK-EPCOS
B82462A2472M000 4.7 0.084 2.00 6.0x6.0x2.5
B82462G4472M 4.7 0.04 1.8 6.3x6.3x3.0

Several parameters are used to select the correct

inductor: maximum rated current, saturation current
and copper resistance (ESR). For boost converters, the
inductor current is much higher than the output current;
the average of the inductor current is equal to the input
current drawn from the input. The lower the inductor
ESR, the higher the efficiency of the converter. This is
a common trade-off in size versus efficiency.
Peak current is the maximum or the limit, and
saturation current typically specifies a point at which
the inductance has rolled off a percentage of the rated
value. This can range from a 20% to 40% reduction in
inductance. As inductance rolls off, the inductor ripple
current increases; as does the peak switch current. It is
important to keep the inductance from rolling off too
much, causing switch current to reach the peak limit.

DS20002234D-page 16  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
5.6 Thermal Calculations estimate, assuming that most of the power lost is
internal to the MCP1640/B/C/D and not CIN, COUT and
The MCP1640/B/C/D is available in two different the inductor. There is some percentage of power lost in
packages: 6-Lead SOT-23 and 8-Lead 2 x 3 DFN. The the boost inductor, with very little loss in the input and
junction temperature is estimated by calculating the output capacitors. For a more accurate estimation of
power dissipation and applying the package thermal internal power dissipation, subtract the IINRMS2 x LESR
resistance (JA). The maximum continuous junction power dissipation.
temperature rating for the MCP1640/B/C/D is +125°C.
To quickly estimate the internal power dissipation for 5.7 PCB Layout Information
the switching boost regulator, an empirical calculation
using measured efficiency can be used. Given the Good printed circuit board layout techniques are
measured efficiency, the internal power dissipation is important to any switching circuitry, and switching
estimated by Equation 5-3. power supplies are no different. When wiring the
switching high-current paths, short and wide traces
should be used. Therefore, it is important that the input
EQUATION 5-3:
and output capacitors be placed as close as possible to
the MCP1640/B/C/D to minimize the loop area.
V OUT  I OUT The feedback resistors and feedback signal should be
 ------------------------------------- – V
 Efficiency  OUT  I OUT  = P Dis routed away from the switching node and the switching
current loop. When possible, ground planes and traces
should be used to help shield the feedback signal and
minimize noise and magnetic interference.
The difference between the first term – input power,
and the second term – power delivered, is the internal
MCP1640/B/C/D power dissipation. This is an

Via to GND Plane

RBOT RTOP

+VIN +VOUT

L CIN MCP1640 COUT

1
GND

GND Via for Enable

FIGURE 5-1: MCP1640/B/C/D SOT-23-6 Recommended Layout.

 2010-2015 Microchip Technology Inc. DS20002234D-page 17

MCP1640/B/C/D

Wired on Bottom
L Plane

+VIN
+VOUT
CIN COUT
GND MCP1640 RTOP

1
RBOT
Enable

GND

FIGURE 5-2: MCP1640/B/C/D DFN-8 Recommended Layout.

DS20002234D-page 18  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
6.0 TYPICAL APPLICATION CIRCUITS

L1
4.7 µH

VOUT
Manganese Lithium 5.0V @ 5 mA
Dioxide Button Cell SW V
OUT
VIN
+ 976 k
CIN COUT
2.0V to 3.2V
4.7 µF EN VFB 10 µF
-
309 k
From PIC® MCU I/O GND

Note: For applications that can operate directly from the battery input voltage during Sleep mode and
require a higher voltage during Normal Run mode, the MCP1640C device provides Input to
Output Bypass when disabled. The PIC® microcontroller is powered by the output of the
MCP1640C. One of its I/O pins is used to enable and disable the MCP1640C. While operating
in Sleep mode, the MCP1640C input quiescent current is typically less than 1 µA.

FIGURE 6-1: Manganese Lithium Coin Cell Application Using Bypass Mode.

L1
10 µH

VOUT
VIN 5.0V @ 350 mA
SW V
3.3V To 4.2V OUTS
VIN VOUTP 976 k
CIN COUT
+
10 µF EN VFB 10 µF
LI-ION

309 k
- PGND SGND

FIGURE 6-2: USB On-The-Go Powered by Li-Ion.

 2010-2015 Microchip Technology Inc. DS20002234D-page 19

MCP1640/B/C/D
NOTES:

DS20002234D-page 20  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
7.0 PACKAGING INFORMATION
7.1 Package Marking Information

6-Lead SOT-23 Example

Part Number Code

MCP1640T-I/CHY BZNN
MCP1640BT-I/CHY BWNN BZ25
MCP1640CT-I/CHY BXNN
MCP1640DT-I/CHY BYNN

8-Lead DFN Part Number Code Example

MCP1640-I/MC AHM
MCP1640T-I/MC AHM
AHM
MCP1640B-I/MC AHP 340
MCP1640BT-I/MC AHP 25
MCP1640C-I/MC AHQ
MCP1640CT-I/MC AHQ
MCP1640D-I/MC AHR
MCP1640DT-I/MC AHR

Legend: XX...X Customer-specific information

Y Year code (last digit of calendar year)
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code
e3 Pb-free JEDEC® designator for Matte Tin (Sn)
* This package is Pb-free. The Pb-free JEDEC designator ( e3)
can be found on the outer packaging for this package.

Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.

 2010-2015 Microchip Technology Inc. DS20002234D-page 21

MCP1640/B/C/D

6-Lead Plastic Small Outline Transistor (CHY) [SOT-23]

Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging

N 4

E
E1

PIN 1 ID BY
LASER MARK
1 2 3

e
e1

A A2 c φ

L
A1
L1

Units MILLIMETERS
Dimension Limits MIN NOM MAX
Number of Pins N 6
Pitch e 0.95 BSC
Outside Lead Pitch e1 1.90 BSC
Overall Height A 0.90 – 1.45
Molded Package Thickness A2 0.89 – 1.30
Standoff A1 0.00 – 0.15
Overall Width E 2.20 – 3.20
Molded Package Width E1 1.30 – 1.80
Overall Length D 2.70 – 3.10
Foot Length L 0.10 – 0.60
Footprint L1 0.35 – 0.80
Foot Angle I 0° – 30°
Lead Thickness c 0.08 – 0.26
Lead Width b 0.20 – 0.51
Notes:
1. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.127 mm per side.
2. Dimensioning and tolerancing per ASME Y14.5M.
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
Microchip Technology Drawing C04-028B

DS20002234D-page 22  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D

6-Lead Plastic Small Outline Transistor (CHY) [SOT-23]

Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging

 2010-2015 Microchip Technology Inc. DS20002234D-page 23

MCP1640/B/C/D


 

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DS20002234D-page 24  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D

Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging

 2010-2015 Microchip Technology Inc. DS20002234D-page 25

MCP1640/B/C/D
NOTES:

DS20002234D-page 26  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
APPENDIX A: REVISION HISTORY

Revision D (September 2015)

The following is the list of modifications:
1. Deleted maximum values for NMOS Switch
Leakage and PMOS Switch Leakage parame-
ters in DC Characteristics table.
2. Updated Figure 2-15 in Section 2.0 “Typical
Performance Curves”.
3. Minor typographical corrections.

Revision C (November 2014)

The following is the list of modifications:
1. Updated Features list.
2. Updated values in the DC Characteristics and
Temperature Specifications tables.
3. Updated Figures 2-6 and 2-15.
4. Updated Section 4.2.1 “Low-Voltage Start-
Up”.
5. Updated Section 5.2 “Adjustable Output
Voltage Calculations and Maximum Output
Current”.
6. Updated Section 5.4 “Output Capacitor
Selection”.
7. Updated markings and SOT-23 package specifi-
cation drawings for CHY designator in
Section 7.0 “Packaging Information”.
8. Minor editorial corrections.

Revision B (March 2011)

The following is the list of modifications:
1. Updated Table 5-2.
2. Added the package markings tables in
Section 7.0 “Packaging Information”.

Revision A (February 2010)

Original release of this document.

 2010-2015 Microchip Technology Inc. DS20002234D-page 27

MCP1640/B/C/D
NOTES:

DS20002234D-page 28  2010-2015 Microchip Technology Inc.

 MCP1640/B/C/D
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, contact your local Microchip representative or sales office.
PART NO. [X](1) X /XX Examples:
a) MCP1640-I/MC: 0.65V, PWM/PFM
Device Tape Temperature Package True Disconnect
and Reel Range Sync Reg.,
8LD-DFN pkg.
b) MCP1640T-I/MC: 0.65V, PWM/PFM
Device MCP1640: 0.65V, PWM/PFM True Disconnect, True Disconnect
Sync Boost Regulator Sync Reg.,
MCP1640B: 0.65V, PWM Only True Disconnect,
8LD-DFN pkg.
Sync Boost Regulator
MCP1640C: 0.65V, PWM/PFM Input to Output Bypass, Tape and Reel
Sync Boost Regulator
MCP1640D: 0.65V, PWM Only Input to Output Bypass, c) MCP1640B-I/MC: 0.65V, PWM-Only
Sync Boost Regulator True Disconnect
Sync Reg.,
8LD-DFN pkg.
Tape and Reel Option T = Tape and Reel (1)
blank = DFN only d) MCP1640BT-I/MC: 0.65V, PWM-Only
True Disconnect
Sync Reg.,
Temperature Range I = -40C to +85C (Industrial) 8LD-DFN pkg.
Tape and Reel
Package CHY* =Plastic Small Outline Transistor (SOT-23), 6-lead e) MCP1640C-I/MC: 0.65V, PWM/PFM
MC =Plastic Dual Flat, No Lead (2x3 DFN), 8-lead Input-to-Output Bypass
*Y = Nickel palladium gold manufacturing designator. Sync Reg.,
8LD-DFN pkg.
f) MCP1640CT-I/MC: 0.65V, PWM/PFM
Input-to-Output Bypass
Sync Reg.,
8LD-DFN pkg.
Tape and Reel
g) MCP1640D-I/MC: 0.65V, PWM-Only
Input-to-Output Bypass
Sync Reg.,
8LD-DFN pkg.
h) MCP1640DT-I/MC: 0.65V, PWM-Only
Input-to-Output Bypass
Sync Reg.,
8LD-DFN pkg.
Tape and Reel
i) MCP1640T-I/CHY: 0.65V, PWM/PFM
True Disconnect
Sync Reg.,
6LD SOT-23 pkg.
Tape and Reel
j) MCP1640BT-I/CHY: 0.65V, PWM-Only
True Disconnect
Sync Reg.,
6LD SOT-23 pkg.
Tape and Reel
k) MCP1640CT-I/CHY: 0.65V, PWM/PFM
Input-to-Output Bypass
Sync Reg.,
6LD SOT-23 pkg.
Tape and Reel
l) MCP1640DT-I/CHY: 0.65V, PWM-Only
Input-to-Output Bypass
Sync Reg.,
6LD SOT-23 pkg.
Tape and Reel
Note 1: Tape and Reel identifier only appears in the
catalog part number description. This identi-
fier is used for ordering purposes and is not
printed on the device package. Check with
your Microchip Sales Office for package
availability with the Tape and Reel option.

 2010-2015 Microchip Technology Inc. DS20002234D-page 29

MCP1640/B/C/D
NOTES:

DS20002234D-page 30  2010-2015 Microchip Technology Inc.

Note the following details of the code protection feature on Microchip devices:
• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Information contained in this publication regarding device Trademarks

applications and the like is provided only for your convenience The Microchip name and logo, the Microchip logo, dsPIC,
and may be superseded by updates. It is your responsibility to
FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer,
ensure that your application meets with your specifications.
LANCheck, MediaLB, MOST, MOST logo, MPLAB,
MICROCHIP MAKES NO REPRESENTATIONS OR
OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC,
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
SST, SST Logo, SuperFlash and UNI/O are registered
IMPLIED, WRITTEN OR ORAL, STATUTORY OR trademarks of Microchip Technology Incorporated in the
OTHERWISE, RELATED TO THE INFORMATION, U.S.A. and other countries.
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR The Embedded Control Solutions Company and mTouch are
FITNESS FOR PURPOSE. Microchip disclaims all liability registered trademarks of Microchip Technology Incorporated
arising from this information and its use. Use of Microchip in the U.S.A.
devices in life support and/or safety applications is entirely at Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo,
the buyer’s risk, and the buyer agrees to defend, indemnify and CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit
hold harmless Microchip from any and all damages, claims, Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet,
suits, or expenses resulting from such use. No licenses are KleerNet logo, MiWi, motorBench, MPASM, MPF, MPLAB
conveyed, implicitly or otherwise, under any Microchip Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach,
intellectual property rights unless otherwise stated. Omniscient Code Generation, PICDEM, PICDEM.net, PICkit,
PICtail, RightTouch logo, REAL ICE, SQI, Serial Quad I/O,
Total Endurance, TSHARC, USBCheck, VariSense,
ViewSpan, WiperLock, Wireless DNA, and ZENA are
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
GestIC is a registered trademark of Microchip Technology
Germany II GmbH & Co. KG, a subsidiary of Microchip
Technology Inc., in other countries.
All other trademarks mentioned herein are property of their
respective companies.
© 2010-2015, Microchip Technology Incorporated, Printed in
the U.S.A., All Rights Reserved.
ISBN: 978-1-63277-829-1

QUALITY MANAGEMENT SYSTEM Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
CERTIFIED BY DNV Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures

== ISO/TS 16949 ==
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.

 2010-2015 Microchip Technology Inc. DS20002234D-page 31

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07/14/15

DS20002234D-page 32  2010-2015 Microchip Technology Inc.