PULAN TECHNOLOGY CO.
, LIMITED
PS3120A
Description Features
The PS3120A is a low noise switched capacitor Fixed 4.94V±3% Output
voltage doubler. It produces a regulated output VIN Range: 2.7V to 4.5V
voltage from a 2.7V to 4.5V input. Low external Output Current: Up to 110mA (VIN≥3V)
parts count (one flying capacitor and two small Up to 230mA (VIN≥3.6V)
bypass capacitors at VIN and VOUT) make the Low Noise Constant Frequency (360kHz)
PS3120A ideally suited for small,
Operation
battery-powered applications.
Shutdown Current <1μA
The PS3120A have thermal shutdown No Inductors
capability and can survive a continuous short Available in Low Profile 6-Lead SOT23
circuit from VOUT to GND. A low current Package
shutdown feature disconnects the load from VIN
and reduces quiescent current to <1μA. Applications
The PS3120A is available in the industry White LED Backlighting
standard SOT-23-6L power packages. Li-Ion Battery Backup Supplies
Smart Card Readers
PCMCIA Local 5V Supplies
Typical Application
C FLY 10µF
4 6
C- C+
DC+ 5 1 VOUT
VIN VOUT
2.7V ~ 4.5V 4.94V
CIN PS3120A COUT
10µF 3 10µF
EN
ON OFF
GND
2
Figure 1: Regulated 4.94V Output
PS3120A-GV2.3 PULAN TECHNOLOGY
1
PULAN TECHNOLOGY CO., LIMITED PS3120A
Pin Assignment and Description
PIN NAME DESCRIPTION
6 5 4
1 VOUT Output
2 GND Ground
3 EN ON/OFF Control (High Enable)
4 C- Flying Capacitor Negative Terminal.
1 2 3 5 VIN Input
SOT-23-6L
6 C+ Flying Capacitor Positive Terminal.
Absolute Maximum Ratings (Note 1)
V IN ……………………………….…………………………….…….….…..….………-0.3V ～ 6V
V OUT ………………………………………………………………………………….….-0.3V ～ 5.5V
V E N ……………………………………………………...…………………….…...……-0.3V ～ 6V
IOUT (Note 2) …………………….................................………………………...................... 300mA
Operating Temperature Range (Note 3)…………………………………………...……-40℃ ～ +85℃
Lead Temperature深圳百盛新纪元半导体有限公司一级代理商
(Soldering 10, sec.) ……………………………………..………………+265℃
Storage Temperature Range ………………………………………………..…..-65℃ ～ +125℃
Note 1: Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device.
Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability.
Note 2: Based on long term current density limitations.
Note 3: The PS3120A are guaranteed to meet performance specifications from 0 C to 70 C. Specifications over the
–40 C to 85 C operating temperature range are assured by design, characterization and correlation with statistical
process controls.
PS3120A-GV2.3 PULAN TECHNOLOGY
2
PULAN TECHNOLOGY CO., LIMITED PS3120A
Electrical Characteristics
Operating Conditions: TA = 25 ℃, VEN = VIN, CIN = COUT = CFLY = 10μF, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Voltage Range 2.7 4.5 V
2.7V <VIN < 5.5V, IOUT <
VOUT Output Voltage Range 65mA 4.8 4.94 5.1 V
ISHDN Shutdown Current VEN = 0V,VOUT = 0V 0.2 μA
INO-LOAD No Load Input Current IOUT = 0mA, VIN = 3V 0.17 mA
VRIPPLE Output Ripple VIN = 3.6V , IOUT = 100mA 20 mVP-P
EFFI Efficiency VIN = 3V, IOUT =100mA 78 %
fOSC Switching Frequency VIN = 3.6V , IOUT = 100mA 360 kHz
VEN EN Voltage High Enable VIN/2 V
PS3120A-GV2.3 PULAN TECHNOLOGY
3
PULAN TECHNOLOGY CO., LIMITED PS3120A
Typical Performance Characteristics
Operating Conditions: TA=25℃, VEN = VIN, CIN = COUT = CFLY = 10μF, unless otherwise noted.
Efficiency vs. Output Current Output Voltage vs. Output Current
90 5
80 VIN =3V 4.9
70 VIN =3.6V 4.8
4.7 VIN =3.6V
Output Voltage (V)
60 VIN =3V
Efficiency (%)
4.6
50
4.5 VIN =4.2V
40 VIN =4.2V 4.4
30
4.3
20 4.2
10 4.1
0 4
50 100 150 200 250 300 50 100 150 200 250 300
Output Current (mA) Output Current (mA)
Output Voltage vs. Supply Voltage Supply Current vs. Supply Voltage
(ILOAD=0mA) (ILOAD=0mA)
5.2 7
5.1
6
5
Supply Current (mA)
Output Voltage (V)
4.9 5
4.8
4
4.7
4.6 3
4.5
2
4.4
4.3 1
4.2 0
2.5 2.9 3.3 3.7 4.1 4.5 2.5 2.9 3.3 3.7 4.1 4.5
Supply Voltage (V) Supply Voltage (V)
PS3120A-GV2.3 PULAN TECHNOLOGY
4
PULAN TECHNOLOGY CO., LIMITED PS3120A
Oscillator Frequency vs.Supply Voltage
(ILOAD=100mA)
500
450
Oscillator Frequency (kHz)
400
350
300
250
200
150
100
50
0
2.5 2.9 3.3 3.7 4.1 4.5
Supply Voltage (V)
Output Noise（VIN=3.6V, ILOAD=100mA） SW Noise（VIN=3.6V, ILOAD=100mA）
PS3120A-GV2.3 PULAN TECHNOLOGY
5
PULAN TECHNOLOGY CO., LIMITED PS3120A
Output Noise（VIN=4.2V, ILOAD=100mA） SW Noise（VIN=4.2V, ILOAD=100mA）
PS3120A-GV2.3 PULAN TECHNOLOGY
6
PULAN TECHNOLOGY CO., LIMITED PS3120A
Pin Functions
VOUT (Pin 1): Regulated Output Voltage. VOUT should be bypassed with a low ESR ceramic capacitor
providing at least 2.2μF of capacitance as close to the pin as possible for best performance.
GND (Pin 2): Ground. These pins should be tied to a ground plane for best performance.
EN (Pin 3): Active Low Shutdown Input. This pin must not be allowed to float.
C- (Pin 4): Flying Capacitor Negative Terminal.
VIN (Pin 5): Input Supply Voltage. VIN should be bypassed with a low ESR ceramic capacitor providing
at least 2.2μF of capacitance as close to the pin as possible for best performance.
C+ (Pin 6): Flying Capacitor Positive Terminal.
Block Diagram
PS3120A-GV2.3 PULAN TECHNOLOGY
7
PULAN TECHNOLOGY CO., LIMITED PS3120A
Application Information
Operation
The PS3120A use a switched capacitor charge pump to boost VIN to a regulated output voltage.
Regulation is achieved by sensing the output voltage through an internal resistor divider and modulating
the charge pump output current based on the error signal. A 2-phase nonoverlapping clock activates the
charge pump switches. The flying capacitor is charged from VIN on the first phase of the clock. On the
second phase of the clock it is stacked in series with VIN and connected to VOUT. This sequence of
charging and discharging the flying capacitor continues at a free running frequency of 360kHz (typ).
In shutdown mode all circuitry is turned off and the PS3120A draw only leakage current from the VIN
supply. Furthermore, VOUT is disconnected from VIN. The EN pin is a CMOS input with a threshold
voltage of approximately 0.8V. The PS3120A is in shutdown when a logic low is applied to the EN pin.
Since the EN pin is high impedance CMOS input it should never be allowed to float. To ensure that its
state is defined it must always be driven with a valid logic level.
VIN, VOUT Capacitor Selection
The style and value of capacitors used with the PS3120A determine several important parameters such
as regulator control loop stability, output ripple, charge pump strength and minimum start-up time.
To reduce noise and ripple, it is recommended that low ESR (< 0.1Ω) ceramic capacitors be used for
both CIN and COUT. These capacitors should be greater than 2.2μF. Tantalum and aluminum capacitors
are not recommended because of their high ESR.
Flying Capacitor Selection
Warning: A polarized capacitor such as tantalum or aluminum should never be used for the flying
capacitor since its voltage can reverse upon start-up of the PS3120A. Low ESR ceramic capacitors
should always be used for the flying capacitor.
The flying capacitor controls the strength of the charge pump. In order to achieve the rated output
current it is necessary to have more than 2.2μF of capacitance for the flying capacitor.
Layout Considerations
Due to its high switching frequency and the high transient currents produced by the PS3120A, careful
board layout is necessary. A true ground plane and short connections to all capacitors will improve
performance and ensure proper regulation under all conditions. Figure 2 shows an example layout for
the PS3120A.
Figure 2: Recommended Layout
PS3120A-GV2.3 PULAN TECHNOLOGY
8
PULAN TECHNOLOGY CO., LIMITED PS3120A
Packaging Information
SOT-23-6L Package Outline Dimension
Dimensions In Millimeters Dimensions In Inches
Symbol
Min Max Min Max
A 1.050 1.250 0.041 0.049
A1 0.000 0.100 0.000 0.004
A2 1.050 1.150 0.041 0.045
b 0.300 0.500 0.012 0.020
c 0.100 0.200 0.004 0.008
D 2.820 3.020 0.111 0.119
E 1.500 1.700 0.059 0.067
E1 2.650 2.950 0.104 0.116
e 0.950(BSC) 0.037(BSC)
e1 1.800 2.000 0.071 0.079
L 0.300 0.600 0.012 0.024
θ 0° 8° 0° 8°
PS3120A-GV2.3 PULAN TECHNOLOGY
9
