tps54362 q1
tps54362 q1
TPS54362-Q1
SLVS845G – MARCH 2009 – REVISED AUGUST 2014
EN
SS
• Qualified for Automotive Applications SYNC
VReg V(Vreg)
RST
BOOT
RT
PH
TPS54362x-Q1
Cdly VSENSE
COMP
RST_TH
GND
OV_TH
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TPS54362-Q1
SLVS845G – MARCH 2009 – REVISED AUGUST 2014 www.ti.com
Table of Contents
1 Features .................................................................. 1 7.2 Functional Block Diagram ....................................... 12
2 Applications ........................................................... 1 7.3 Feature Description................................................. 13
3 Description ............................................................. 1 7.4 Device Functional Modes........................................ 20
4 Revision History..................................................... 2 8 Application and Implementation ........................ 22
8.1 Application Information............................................ 22
5 Pin Configuration and Functions ......................... 4
8.2 Typical Application .................................................. 22
6 Specifications......................................................... 5
6.1 Absolute Maximum Ratings ...................................... 5 9 Power Supply Recommendations...................... 30
6.2 Handling Ratings....................................................... 5 10 Layout................................................................... 30
6.3 Recommended Operating Conditions....................... 6 10.1 Layout Guidelines ................................................. 30
6.4 Thermal Information ................................................. 6 10.2 Layout Example .................................................... 31
6.5 Electrical Characteristics........................................... 7 11 Device and Documentation Support ................. 32
6.6 Timing Requirements ................................................ 8 11.1 Trademarks ........................................................... 32
6.7 Switching Characteristics .......................................... 8 11.2 Electrostatic Discharge Caution ............................ 32
6.8 Typical Characteristics .............................................. 9 11.3 Glossary ................................................................ 32
7 Detailed Description ............................................ 12 12 Mechanical, Packaging, and Orderable
7.1 Overview ................................................................. 12 Information ........................................................... 32
4 Revision History
Changes from Revision F (May 2014) to Revision G Page
• Changed all text, tables and graphics to the new data sheet template. ................................................................................ 1
• Changed pinout drawing......................................................................................................................................................... 4
• Changed parameter symbols for JEDEC compliance throughout the data sheet ................................................................. 4
• Added a row for the Rslew pin to the Absolute Maximum Ratings table ............................................................................... 5
• Changed symbol for thermal resistance from θ to Rθ in the Thermal Information table ....................................................... 6
• Added Ilkg parameters for EN pin on TPS54362B-Q1 device................................................................................................. 7
• Revised Figure 22 ............................................................................................................................................................... 22
• Changed value of R4 in Output Voltage and Feedback Resistor Selection section ............................................................ 25
• Changed several values in the Overvoltage Resistor Selection section .............................................................................. 25
• Changed several values in the Reset-Threshold Resistor Selection section....................................................................... 25
• Changed the voltage value in the Undervoltage Threshold for Low-Power Mode and Load-Transient Operation section . 26
• Added the TPS54362B-Q1 part number to the text of the Soft-Start Capacitor section ...................................................... 26
• Changed calculated values for loop compensation components ......................................................................................... 27
• Removed TPS54362-Q1 and TPS54362 from data sheet; added -Q1 to TPS54362A part numbers. .................................. 1
• Removed Ordering Information table; see Package Option Addendum for ordering information. ......................................... 1
• Removed items 3 and 4 from the Soft Start (SS) section, also removed the sentence: Item 3 and item 4 are not
applicable for TPS54362A-Q1. ............................................................................................................................................. 15
• Removed the following sentence from the Soft-Start Capacitor section: Equation 4 has to be satisfied in addition to
the other conditions stated in the soft start section of this document (not applicable for TPS54362A-Q1). ........................ 26
NU 1 20 BOOT
NU 2 19 VIN
SYNC 3 18 VIN
LPM 4 17 PH
EN 5 16 VReg
RT 6 15 COMP
Rslew 7 14 VSENSE
RST 8 13 RST_TH
Cdly 9 12 OV_TH
GND 10 11 SS
NU – Make no external connection
Pin Functions
PIN
I/O DESCRIPTION
NAME NO.
BOOT 20 O External bootstrap capacitor to PH to drive the gate of the internal switching FET
Cdly 9 I/O External capacitor to ground to program power-on-reset delay.
COMP 15 I/O Error-amplifier output to connect external compensation components
EN 5 I Enable pin, internally pulled up. This pin requires an external pullup or pulldown to enable or disable the
device.
GND 10 O Ground pin
LPM 4 I Low-power mode control using digital input signal. An internal pulldown resistor of 62 kΩ (typical)
connects to ground.
NU 1 — Connect to ground
2
OV_TH 12 I Sense input for overvoltage detection on regulated output. This pin monitors the V(Vreg) output voltage as
divided by the external resistor network connecting between the VReg pin and ground. The resistor
network programs the threshold voltage.
PH 17 O Source of the internal switching FET
Rslew 7 O External resistor to ground to control the slew rate of the internal switching FET
RST 8 O Active-low, open-drain reset output connected to external bias voltage through a resistor, asserted high
after the device starts regulating
RST_TH 13 I Sense input for undervoltage and reset voltage detection on regulated output to initiate a reset-output
signal. This pin monitors the V(Vreg) output voltage as divided by the external resistor network connecting
between the VReg pin and ground. The resistor network programs the threshold voltage.
RT 6 O External resistor to ground to program the internal oscillator frequency
SS 11 I/O External capacitor to ground to program soft-start time
SYNC 3 I External synchronization clock input to override the internal oscillator clock. An internal pulldown resistor
of 62 kΩ (typical) connects to ground.
VIN 18 I Unregulated input voltage. Connect pin 18 and pin 19 together externally.
19
VReg 16 I Internal low-side FET to load output during start-up or limit overshoot
VSENSE 14 I Inverting node of error amplifier for voltage-mode control
Thermal pad — The thermal pad connects electrically to exposed ground pad on PCB for proper thermal performance.
6 Specifications
6.1 Absolute Maximum Ratings
(1)
over operating free-air temperature (unless otherwise noted)
MIN MAX UNIT
EN –0.3 60
VIN –0.3 60
VReg –0.3 20
LPM –0.3 5.5
Input voltage V
OV_TH –0.3 5.5
RST_TH –0.3 5.5
SYNC –0.3 5.5
VSENSE –0.3 5.5
BOOT –0.3 65
–0.3 60
30 ns –2 60
V
PH 200 ns –1 60
TJ = –40 –0.85 60
TJ = 125 –0.5 60
Output voltage
RT –0.3 5.5
RST –0.3 5.5
Rslew –0.3 5.5
V
Cdly –0.3 8
SS –0.3 8
COMP –0.3 7
TJ Operating virtual junction temperature range –40 150 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(1) AEC Q100-002 indicates HBM stressing is done in accordance with the ANSI/ESDA/JEDEC JS-001 specification.
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
Quiescent current; low-power I(VReg) < 1 mA, V(VIN) = 12 V, –40 < TJ < 150°C 75
I(q-LPM) μA PT
mode I(VReg) < 1 mA, V(VIN) = 24 V, TA = 25°C 85
I(VReg) < 1 mA, V(VIN) = 24 V, –40 < TJ < 150°C 85
V(EN) = 0 V, device is OFF, TA = –40°C to 125°C, 10
I(SD) Shutdown V(VIN) = 24 V μA PT
V(EN) = 0 V, device is OFF, TA = 25°C, V(VIN) = 12 V 1 4
TRANSITION TIMES (LOW-POWER AND NORMAL MODES)
Transition delay from normal
td(1) V(VIN) = 12 V, V(VReg) = 5 V, I(VReg) = 1 A to 1 mA 100 μs CT
mode to low-power mode
Transition delay from low-power
td(2) V(VIN) = 12 V, V(VReg) = 5 V, I(VReg) = 1 mA to 1 A 5 μs CT
mode to normal mode
SWITCH-MODE SUPPLY (VReg)
V(VReg) Regulator output V(VSENSE) = 0.8-V reference 0.9 18 V Info
V(VSENSE) Feedback voltage V(VReg) = 0.9 V to 18 V, V(VIN) = 7 V to 48 V 0.788 0.8 0.812 V CT
rDS(on) Internal switch resistance Measured across VIN and PH, I(VReg) = 500 mA 500 mΩ PT
Switch current limit, cycle-by-
I(CL) V(VIN) = 12 V 4 6 8 A Info
cycle
t(ON-Min) Duty-cycle pulse duration (ON) 50 100 150 ns Info
t(OFF-Min) Duty-cycle pulse duration (OFF) 100 200 250 ns Info
f(SW) Switch-mode frequency Set using external resistor on RT pin 0.2 2.2 MHz PT
Accuracy of f(SW) –10% 10% PT
Sink current in start-up V(OV_TH) = 0 V, V(VReg) = 10 V 1 mA
I(Sink) Info
condition
I(Limit) Sink-current limit 0 V < V(OV_TH) < 0.8 V, V(VReg) = 10 V 80 mA Info
ENABLE (EN)
VIL Low input threshold 0.7 V PT
VIH High input threshold 1.7 V PT
A-revision, V(EN) = 60 V 100 135
A-revision,, V(EN) = 12 V 8 15
Ilkg Leakage into EN pin μA PT
B-revision, V(EN) = 60 V 10
B-revision, V(EN) = 12 V 2
RESET DELAY (Cdly)
External capacitor charge
IO V(EN) = high 1.4 2 2.6 μA PT
current
VThreshold Switching threshold Output voltage in regulation 2 V PT
LOW-POWER MODE (LPM)
VIL Low input threshold V(VIN) = 12 V 0.7 V PT
VIH High input threshold V(VIN) = 12 V 1.7 V PT
Ilkg Leakage into LPM pin V(LPM) = 5 V 65 95 μA PT
RESET OUTPUT (RST)
V(RST_TH) Reset threshold for RST_TH pin 0.768 0.832 V PT
SOFT START (SS)
I(SS) Soft-start source current 40 50 60 μA PT
(1) PT = Production tested; CT = Characterization tested only, not production tested; Info = User information only, not production tested
Copyright © 2009–2014, Texas Instruments Incorporated Submit Documentation Feedback 7
Product Folder Links: TPS54362-Q1
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(2) The SYNC input clock can have a maximum frequency of 2× the programmed clock frequency up to a maximum value of 1.1 MHz.
(1) PT = Production tested; CT = Characterization tested only, not production tested; Info = User information only, not production tested
(2) The SYNC input clock can have a maximum frequency of 2× the programmed clock frequency up to a maximum value of 1.1 MHz.
(1) PT = Production tested; CT = Characterization tested only, not production tested; Info = User information only, not production tested
(2) The SYNC input clock can have a maximum frequency of 2× the programmed clock frequency up to a maximum value of 1.1 MHz.
90 95
85 90
85
80
Efficiency (%)
Efficiency (%)
80
75
75
70
70
65 65 V(VIN) = 6 V
Rslew = 5 kW
Rslew = 35 kW V(VIN) = 20 V
60 60
0 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 3
Load Current (A) Load Current (A)
V(VIN) = 12 V V(VReg) = 5 V f(SW) = 500 kHz V(VReg) = 5 V f(SW) = 500 kHz L = 22 µH
L = 22 µH C4 (output) = 100 µF TA = 25ºC C4 (output) = 100 µF Rslew = 5 kΩ TA = 25ºC
Figure 1. FET Switching (Slow Slew Rate) Figure 2. Fast Slew Rate on Switching FET
7
6.5 7
6
6
Intput Voltage (V)
5.5
Intput Voltage (V)
5
5
4.5
4 4
3.5 200 mA No Load
536 mA 10 mA
3 3
1.4 A 50 mA
2.5
3A 100 mA
2 2
0 1 2 3 4 5 6 2.5 3 3.5 4 4.5 5 5.5
Figure 3. Load Current > 100 mA Figure 4. Load Current < 100 mA
0
0 0.05 0.1 0.15 0.2
Load Current (A)
V(VReg) = 5 V TA = 25ºC
NOTE
Tracking: The input voltage at which the output voltage drops approximately –0.7 V of the
regulated voltage or for low input voltages (tracking function) over the load range.
Start: The input voltage required to achieve 5-V regulation on power up with the stated
load currents.
68 77
67 76
75
Quiescent Current (μA)
66
Quiescent Current (μA)
74
65
73
64
72
63
71
62 70
61 69
60 68
59 67
–40 –20 0 20 40 60 80 100 120 140 –40 –20 0 20 40 60 80 100 120 140
Free-Air Temperature (°C) Free-Air Temperature (°C)
V(VIN) = 12 V V(VIN) = 24 V
Figure 6. LPM, Quiescent Current Variation With Figure 7. LPM, Quiescent Current Variation with
Temperature Temperature
4 9
3.5 8
Shutdown Current (μA)
5.6
5.55
Current Consumption (mA)
5.5
5.45
5.4
5.35
5.3
5.25
–50 –30 –10 10 30 50 70 90 110 130 150
Free-Air Temperature (°C)
EN = High V(VIN) = 12 V
798.5 1006
Internal Reference Voltage (mV)
1004
Voltage Drop on Rslew (mV)
798
797.5 1002
797 1000
796.5 998
796 996
795.5 994
–40 –20 0 20 40 60 80 100 120 140 –40 –20 0 20 40 60 80 100 120 140
Free-Air Temperature (°C) Free-Air Temperature (°C)
V(VIN) = 12 V
Figure 11. Internal Reference Voltage Figure 12. Voltage Drop on Rslew for Current Reference
7 Detailed Description
7.1 Overview
The TPS54362-Q1 device is a 60-V, 3-A DC-DC step-down (buck) converter using a voltage-control-mode
scheme. The device features a supervisory function for power-on-reset during system power on. When the
output voltage has exceeded the threshold set by the resistor network connected to the RST_TH pin, a delay of 1
ms per nF (based on the capacitor value on the RSTDLY pin) occurs before the release to high of the RST pin.
Conversely on power down, once the output voltage falls below the same set threshold, the device pulls RST low
only after a de-glitch filter of approximately 20 μs (typical) expires. The implementation of this function prevents
the triggering of RST due to fast transient line noise on the output supply.
An overvoltage monitor function limits output voltage to the threshold set by OV_TH. The external resistor
network sets both the RST_TH and OV_TH monitoring voltages to be a pre-scale of the output voltage, and the
internal bias voltages of the voltage comparators (0.8 V typical) are the basis of the thresholds.
The RST_TH setting is the basis for detection of undervoltage on the output, which invokes low assertion of the
RST pin. The OV_TH setting is the basis for detection of overvoltage on the output, which does not invoke low
assertion of the RST pin. However, the device commands the internal switch to turn OFF.
In systems where power consumption is critical, implementation of low-power mode reduces the non-switching
quiescent current during light load conditions. The system entering discontinuous current mode (DCM) for at
least 100 μs determines PFM operation. When the device enters discontinuous mode depends on the selection
of external components.
If excessive power dissipation causes invocation of thermal shutdown, the device disables the internal switch,
and the regulated output voltage starts to decrease. Depending on the load line, the regulated voltage could
decay and the RST_TH threshold may assert the RST output low.
BOOT
20
Error R9
amp VSENSE R4
SYNC 3 - 14
SS R5
9 + 11
Cdly C8 C5
0.8-V Vref(1) C6
C2 V(Vreg) 15
+ 0.82-V Vref(3) COMP R6
R12 -
+ 0.8-V V R1
ref(1) RST_TH
8 - 13
RST Voltage C10
R2
Reset with comp OV_TH
- 12
GND Delay Timer
10 + 0.8-V V R3
ref(1) C9
OPERATING VOLTAGE
FUNCTION OUTPUT CURRENT CAPABILITY COMMENTS
RANGE
V(VReg) = 0.9 V to 18 V and I(VReg) up to 3 Optimum performance: always set V(VIN)-to-
A; however, at higher output power the V(VReg) ratios such that the minimum required
Buck 3.6 V to 48 V
device requires derating for maximum duty cycle pulse (t(ON-Min)) > 150 ns. The
temperature rating. minimum off-time is 250 ns for all conditions.
where
• R5 and R4 are feedback resistors
• Vref = 0.8 V (typical) (1)
The internal reference voltage has a ±1.5% tolerance. The overall output voltage tolerance depends on the
external feedback resistors. To determine the overall output voltage tolerance, use the following relationship:
V(VReg-tol) = V(VRef-tol) + (R4 / (R4 + R5)) ´ (R4-tol+ R5-tol)
where
• R4 and R5 are feedback resistors
• Vref = 0.8 V (typical) (2)
The VReg pin also connects internally to a load of 100 Ω, which turns ON in the following conditions:
• During startup conditions, when the device is powered up with no load, or whenever EN is toggled, the
internal load connected to the VReg pin turns ON for about 100 µs to charge the bootstrap capacitor to
provide gate drive voltage to the switching transistor.
• During normal operating conditions, when the regulated output voltage exceeds the overvoltage threshold
(preset by external resisitors R1, R2, and R3), the internal load turns ON, pulling this pin down to bring the
regulated output voltage down.
Typically, the output uses a capacitor within the range of 10 μF to 400 μF. This pin must have a filter capacitor
with low ESR characteristics in order to minimize output ripple voltage.
2000
8V
1800 14 V
1400 40 V
1200
1000
800
600
400
200
0 100 200 300 400 500 600
Resistor on RT (kW)
where
• C = capacitance on the Cdly pin (3)
VIN VIN
SS SS
Cdly
Cdly
td(POR)
RST
RST
20 ms (Typical
Deglitch Time)
Figure 14. Power-On Condition, Reset Line Figure 15. Power-Down Condition, Reset Line
Setting the overcurrent indicator to true triggers overcurrent protection. The MOSFET turns off for the rest of the
cycle after a propagation delay. The name of the overcurrent protection scheme is cycle-by-cycle current limiting.
If the sensed current continues to increase during cycle-by-cycle current limiting, the temperature of the device
starts rising. At the temperature limit, thermal shutdown (TSD) kicks in and shuts down switching until the device
cools sufficiently.
CAUTION
In certain conditions, device damage may occur under a shorted load condition,
depending on the supply voltage. The design of the TPS54362-Q1 devices is for
protection from damage due to a shorted load condition using a cycle-by-cycle current
limit, the short-circuit protection function, and/or the thermal shutdown function.
Short-circuit detection protects the device from damage when encountering a 0-Ω
short-circuit condition. However, damage to a device may occur when the shorted load
has some resistivity and the output level stays higher than the short-circuit detection
level of 0.2 V. In this case, the inductor current increases until the junction temperature
of the device hits the thermal shutdown threshold, but damage to the switching FET
may occur before thermal shutdown.
This failure only occurs during an output short circuit with some resistivity when the
supply voltage is above 18 V.
35 350
8V
30 300 14 V
24 V
25 250 40 V
Rise Time (ns)
20 200
15 150
10 8V 100
14 V
5 24 V 50
40 V
0 0
10 20 30 40 50 60 70 10 20 30 40 50 60 70
Slew Resistor (kW) Slew Resistor (kW)
Figure 16. FET Rise Time Figure 17. FET Fall Time
Example:
R1 = 36 kΩ
R2 = 600 Ω
R3 = 6.6 kΩ
V(VReg _RST) = 0.8 ´ (43.2 kW) / 7.2 kW = 4.8 V (7)
V(VReg _OV) = 0.8 ´ (43.2 kW) / 6.6 kW) = 5.24 V (8)
VReg
C4
R1
RST _TH
R2
C10
OV_TH
R3
C9
Typical values for the RST_TH and OV_TH capacitors are in the 10-pF to 100-pF range for total resistance on
the RST_TH-OV_TH divider of < 200 kΩ.
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Product Folder Links: TPS54362-Q1
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V(VReg_OV)
V(VReg_UL)
V(VReg_LL)
VReg Output
C7 R9 C5 R6
ESRC4 R4
C4 VSENSE
Error
Amplifier
R5
COMP
Vref = 0.8 V
(C5 + C8)
f (p1) =
2p ´ R6 ´ (C5 ´ C8) (15)
1
f (p2) =
2p ´ R9 ´ C7 (16)
1
f (z1) =
2p ´ R6 ´ C5 (17)
1
f (z2) =
2p ´ (R4 + R9 ) ´ C7 (18)
Modulator Gain
Compensation
Gain
Closed-Loop Gain
f(LC) f(ESR)
Frequency - Hz
NOTE
Being in LPM prevents enabling of the OV_TH circuit.
Active or normal mode: When the device is in CCM or DCM with LPM = High
LPM: When the device is in DCM with LPM = Low
1
C11 + C1 2
V(VIN) = 8 V to 28 V
0.1uF 220uF 1
U1 TPS54362x-Q1
2
1 20 C3 0.1uF
GND NC BOOT
2 19 GND
GND NC VIN
V(VReg)
3 18
SYNC VIN L1 22uH
4 17 1 2
GND LPM PH
J2
1
V(VReg) R11 102k 5 16 V(VReg) D2 R9
EN VReg GND
C12 + C4 2
R8 221k 6 15
C5 330pF 2.55k V(VReg) = 3.3 V
GND RT COMP
R4 0.1uF 100uF 1
R7 30.1k 7 14
IO = 2.5 A
2
GND Rslew VSENSE
C8 R6 C7 187k
V(VReg) R12 2k 8 13
RST RST_TH GND
22pF 274K 220pF
C2 199.2nF 9 12
GND CDLY OV_TH
10 11
GND AGND SS
PAD
C6 V(VReg) R5
21
150 nF R1 35.7k
GND
82.5k
GND GND
R2 C10
2.32k 22pF
C9 R3 GND
22pF 15k
GND GND
where
• f(SW-max) = 770 kHz
• t(ON-Min) = 150 ns from the Electrical Characteristics table (19)
Because the oscillator can vary 10%, decrease the frequency by 10%. Further, to keep the switching frequency
outside the AM band, one can select f(sw) as 400 kHz (500 kHz in the application example).
where
• I(Ripple) = 0.2 × 2.5 = 0.5 A (peak-to-peak) (20)
Calculate inductor L(O):
L (O-min) =
(VI(max) - VO ) × VO (Henries)
f (SW) × I(Ripple) × VI(max)
where
• f(SW) is the regulator switching frequency
• I(Ripple) = Allowable ripple current in the inductor, typically 20% of maximum IO (21)
The RMS (root-mean-square) and peak current flowing in the inductor is:
(I(Ripple) ) 2
IL(RMS) = (I O )2 + (Amperes)
12 (22)
Inductor peak current:
I(Ripple)
IL(pk) = I O + (Amperes)
2 (23)
The capacitance value determines the modulator pole and the rolloff frequency due to the LC output filter double
pole – Equation 9.
The output ripple voltage is a product of the output capacitor ESR and ripple current – Equation 27.
Using Equation 24, the minimum capacitance needed to maintain the desired output voltage during a high-to-low
load transition and prevent overshoot is 157 μF.
L ´ éI O(max)2 - I O(min)2 ù
C(O) = ë û (Farads)
2 2
VO(max) - VO(min)
where
• IO(max) is the maximum output current
• IO(min) is the minimum output current
The difference between the output current maximum-to-minimum is the worst-case load step in the system
• VO(max) is maximum tolerance of regulated output voltage
• VO(min) is the minimum tolerance of regulated output voltage (24)
The calculation of minimum capacitance needed for transient load response, using Equation 25, yields 53 μF.
2 ´ DI O
C(O) > (Farads)
f (SW ) ´ DVO (25)
The calculation of minimum capacitance needed for output voltage ripple specification, using Equation 26, yields
1.18 μF.
1 1
C(O) > ´ (Farads)
8 ´ f (SW ) æ VO(Ripple) ö
ç ÷
ç I(Ripple) ÷
è ø (26)
The most critical condition based on the foregoing calculations indicates that the output capacitance must be a
minimum of 157 μF to keep the output voltage in regulation during load transients.
Factoring in additional capacitance de-ratings for temperature, aging, and dc bias yields a value of 220 μF.
Equation 27 calculates the ESR required to meet the ripple-voltage tolerance of the system, but for system
stability the ESR should not exceed 100 mΩ.
Maximum ESR of the out capacitor based on output ripple voltage specification is:
VO(Ripple)
R (ESR) < (Ohms)
I(Ripple) (27)
Output capacitor root-mean-square (rms) ripple current. This is to prevent excess heating or failure due to high
ripple currents. This parameter is sometimes specified by the manufacturers.
I O(RMS) =
VO ´ (VI(max) ) - VO ) (Amperes)
12 ´ VI(max) ´ L (O) ´ f (SW ) (28)
æ é VI(max) - VO ù ´ I O ´ V(fd) ö æé 2 ö
ç VI - V(fd) ûù ´ f (SW ) ´ C j ÷
P(diode) = çë û ÷ +
ç
ë
÷ (Watts)
ç VI(max) ÷ ç 2 ÷
è ø è ø
where
• VF = forward conducting voltage of Schottky diode
• Cj = junction capacitance of the Schottky diode (29)
The recommended part numbers of the Flyback Schottky diodes are PDS360 and SBR8U60P5.
where
• IL(DCM) = Output load current at which the converter is operating in discontinuous mode
• IL(LPM) = Output load current at which the converter is operating in low-power mode
• D = Duty cycle (32)
1
C7 =
p ´ R9 ´ f (SW) (38)
8.2.2.14 Compensation
4.00
3.50
3.00
Power Dissipation (W)
2.50
2.00
1.50
1.00
0.50
0.00
-40 -20 0 20 40 60 80 100 120 140
Ambient Temperture (C)
Figure 24. Transition Response (IO from 0 A to 2 A) Figure 25. Transition Response (IO from 0 A to 3 A)
CH4: PH = 5 V/div
CH4: PH = 5 V/div
Figure 26. Output Ripple (IO = 0 A) Figure 27. Output Ripple (IO = 100 mA)
1 μs/div 1 μs/div
CH2: VIN CH3: Vreg CH4: PH (1 µs/div) CH2: VIN CH3: Vreg CH4: PH (1 µs/div)
V(VIN) = 12 V V(VReg) = 5 V CH4 = 519.1 kHz V(VIN) = 12 V V(VReg) = 5 V CH4 = 523.5 kHz
Figure 28. Output Ripple (IO = 1 A) Figure 29. Output Ripple (IO = 3 A)
10 Layout
10.1.1 Inductor
Use a low-EMI inductor with a ferrite-type shielded core. Other types of inductors may be used; however, they
must have low-EMI characteristics and be located away from the low-power traces and components in the circuit.
10.1.3 Feedback
Route the feedback trace such that there is minimum interaction with any noise sources associated with the
switching components. Recommended practice is to place the inductor away from the feedback trace to prevent
EMI noise.
Output
Capacitor
Topside Supply Area
Ground
Input Capacitor Plane
Output
Catch Diode Inductor
NC BOOT
NC VIN
SYNC VIN
LPM PH
EN VReg
Compensation Network
RT COMP
Rslew VSENSE
Resistor
RST RST_TH
Supervisor Network Divider
Cdly OV_TH
Thermal Via
Signal Via
11.3 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
www.ti.com 10-Dec-2020
PACKAGING INFORMATION
Orderable Device Status Package Type Package Pins Package Eco Plan Lead finish/ MSL Peak Temp Op Temp (°C) Device Marking Samples
(1) Drawing Qty (2) Ball material (3) (4/5)
(6)
TPS54362AQPWPRQ1 NRND HTSSOP PWP 20 2000 RoHS & Green NIPDAU Level-3-260C-168 HR -40 to 125 54362AQ1
TPS54362BQPWPRQ1 ACTIVE HTSSOP PWP 20 2000 RoHS & Green NIPDAU Level-3-260C-168 HR -40 to 125 54362BQ
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com 10-Dec-2020
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com 5-Dec-2023
B0 W
Reel
Diameter
Cavity A0
A0 Dimension designed to accommodate the component width
B0 Dimension designed to accommodate the component length
K0 Dimension designed to accommodate the component thickness
W Overall width of the carrier tape
P1 Pitch between successive cavity centers
Sprocket Holes
Q1 Q2 Q1 Q2
Pocket Quadrants
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com 5-Dec-2023
Width (mm)
H
W
Pack Materials-Page 2
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