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PL5920
21V, 1.8A, 600KHz Synchronous Step-Down DC/DC Converter
Description
The PL5920 is a synchronous step-down DC/DC converter that provides wide 4.5V to 21V input
voltage range and 1.8A continuous load current capability.
The PL5920 fault protection includes cycle-by-cycle current limit, UVLO, output overvoltage
protection and thermal shutdown. The adjustable soft-start function prevents inrush current at turn-on. This device uses current mode control scheme which provides fast transient response. Internal Compensation function reduces external compensation components and simplifies the design process. In shutdown mode, the supply current is less than 1μA.
The PL5920 is available in a SOT-23-6 package, provides good thermal conductance.
Features
● High Efficiency up to 94%
● Low Rds(on) Integrated Power MOSFET ● Internal Compensation Function ● Wide Input Voltage Range: 4.5V to 21V ● Adjustable Output Voltage from 0.8V to 17.85V ● 1.8A Output Current
● Fixed 600KHz Switching Frequency
● Current Mode Operation ● Cycle-by-Cycle Current Limit
● Over-Temperature Protection with Auto Recovery ● Output Overvoltage Protection ● Under Voltage Lockout ● <1μA Shutdown Current ● SOT-23-6 Package
Applications
● STB (Set-Top-Box) ● LCD Displays, TVs ● Distributed Power Systems ● Networking, XDSL Modems
DC-DC Synchronous Step Down PL5901A PL5902 PL5903 PL5920 VIN VOUT Iout(MAX) Efficiency (%) Oscillation Compact Frequency Package SOT23-5 SOT23-5 SOT23-6 SOT23-6 2.5V-5.5V ADJ 2.5V-5.5V 2.7V-5.5V 4.5V-21V VIN ADJ ADJ ADJ VOUT 1.2A 86% 1.5MHZ （VIN=4.2V/5V，Vout=3.3V） 2.0A 88% 1MHZ （VIN=4.2V/5V，Vout=3.3V） 3.0A % 1MHZ （VIN=4.2V/5V，Vout=3.3V） 1.8A / 2A 94% 600KHZ Iout(MAX) Accuracy …… LDO Low Dropout Regulator PL3501 PL3502 Quiescent Compact Current Package 1µA 35µA DFN-4L (EN Pin) SOT23-5 (EN Pin) 2.7V-5.5V 1.2V,1.8V,2.8V 150MA 3.0V,3.3V 2.0V-5.5V 1.2V,1.8V,2.8V 300MA 3.0V,3.3V ±1.5% ±2%
PL5920v2.10
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PULAN TECHNOLOGY CO.,LIMITED
PL5920
C30.1μFTypical Application Circuit
R3 100kΩ
4SHDNVIN4.5V to 21VC110μF/25V CERAMIC x 21BSTLX6L14.7μHVOUT3.3VR130.9kΩ 1% (optional)5VINPL5920FB3C4C222μF/6.3V CERAMIC x 2
GND2R29.76kΩ 1%
Figure 2. CIN /COUT use Ceramic Capacitors Application Circuit
R3 100kΩ
C30.1μF
VIN4.5V to 21V4SHDN5C4C10.1μF/25V100μF/25V EC x 1 CERAMIC x 11BSTLX6L14.7μHVOUT3.3VR130.9kΩ 1% C2100μF/6.3VEC x 1VIN
PL5920FBGND23
R29.76kΩ 1%
Figure 3. CIN /COUT use Electrolytic Capacitors Application Circuit
VOUT 1.2V 1.8V 2.5V 3.3V 5V 1.2V 1.8V 2.5V 3.3V 5V R1 4.99kΩ 4.99kΩ 4.99kΩ 30.9kΩ 30.9kΩ 4.99kΩ 4.99kΩ 4.99kΩ 30.9kΩ 30.9kΩ R2 10kΩ 3.92kΩ 2.32kΩ 9.76kΩ 5.76kΩ 10kΩ 3.92kΩ 2.32kΩ 9.76kΩ 5.76kΩ C4 10pF~1nF 10pF~1nF 10pF~1nF 10pF~1nF 10pF~1nF -- -- -- -- -- L1 2.2μH 2.2μH 4.7μH 4.7μH 4.7μH 2.2μH 2.2μH 4.7μH 4.7μH 4.7μH COUT 22μF MLCC x2 22μF MLCC x2 22μF MLCC x2 22μF MLCC x2 22μF MLCC x2 100μF EC x1 100μF EC x1 100μF EC x1 100μF EC x1 100μF EC x1
Table 1. Recommended Component Values
PL5920v2.10
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PULAN TECHNOLOGY CO.,LIMITED
PL5920
Pin Assignments
LXVINSHDN65243●1BSTGNDFB
Figure 1. Pin Assignment of PL5920
Functional Pin Description
Pin Name Pin No. FB VIN
Pin Function Voltage Feedback Input Pin. Connect FB and VOUT with a resistive voltage divider. This IC senses feedback voltage via FB and regulates it at 0.8V. Power Supply Input Pin. Drive VIN pin by 4.5V to 21V voltage to power on the chip. Enable Input Pin. This pin is a digital control input that turns the converter on or off. Connect to VIN with a 100KΩ resistor for self-startup. Ground Pin. Power Switching Output. LX is the output of the internal high side NMOS switch. High Side Gate Drive Boost Pin. A 10nF or greater capacitor must be connected from this pin to LX. It can boost the gate drive to fully turn on the internal high side NMOS. 3 5 4 2 6 SHDN GND LX BST 1
PL5920v2.10
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PULAN TECHNOLOGY CO.,LIMITED
PL5920
Block Diagram
VINISENInternalRegulator VCCSHDN1MUVLO&POROTPVCCOVPOscillatorBSTSFB CurrentCompROTPOVPUVLOPWMControlDriverLogicHigh-Side MOSFETLX0.8V Current LimitLow-Side MOSFETGND
Figure 4. Block Diagram of PL5920
Absolute Maximum Ratings (Note 1)
● Supply Voltage VIN ------------------------------------------------------------------------------------------- -0.3V to +23V ● Enable Voltage VSHDN -------------------------------------------------------------------------------------- -0.3V to +23V ● LX Voltage VLX (50ns) -------------------------------------------------------------------------------------- -1V to VIN+0.3V ● BST Pin Voltage VBST -------------------------------------------------------------------------------------- VLX-0.3V to VLX+6V ● All Other Pins Voltage ------------------------------------------------------------------------------------- -0.3V to +6V ● Maximum Junction Temperature (TJ) ------------------------------------------------------------------ +150°C ● Storage Temperature (TS) -------------------------------------------------------------------------------- -65°C to +150°C ● Lead Temperature (Soldering, 10sec.) ---------------------------------------------------------------- +260°C ● Power Dissipation @TA=25°C, (PD)
SOT-23-6 -------------------------------------------------------------------------------------------- +0.40W
● Package Thermal Resistance, (θJA):
SOT-23-6 -------------------------------------------------------------------------------------------- +250°C/W
● Package Thermal Resistance, (θJC):
SOT-23-6 -------------------------------------------------------------------------------------------- +130°C/W
Note 1：Stresses beyond this listed under “Absolute Maximum Ratings\" may cause permanent damage to the device.
PL5920v2.10
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PULAN TECHNOLOGY CO.,LIMITED
PL5920
Recommended Operating Conditions
● Supply Voltage VIN ------------------------------------------------------------------------------------------- +4.5V to +21V ● Enable Voltage VSHDN -------------------------------------------------------------------------------------- 0V to VIN ● Operation Temperature Range -------------------------------------------------------------------------- -40°C to +85°C
Electrical Characteristics
(VIN=12V, TA=25°C, unless otherwise specified.) Parameter Symbol VIN Input Supply Voltage VIN Quiescent Current VIN Shutdown Supply Current Feedback Voltage Feedback OVP Threshold Voltage High-Side MOSFET RDS(ON) (Note 2) Low-Side MOSFET RDS(ON) (Note 2) High-Side MOSFET Leakage Current High-Side MOSFET Current Limit (Note 2) Low-Side MOSFET Current Limit (Note 2) Error Amplifier Voltage Gain (Note 2) Oscillation frequency Short Circuit Oscillation Frequency Maximum Duty Cycle Minimum On Time (Note 2) Input UVLO Threshold Under Voltage Lockout Threshold Hysteresis Conditions Min 4.5 VSHDN=1.8V, VFB=1.0V VSHDN=0V 4.5V≦VIN≦21V Typ Max 21 2.5 Unit V mA 1 μA V V mΩ mΩ 10 μA A A V/V 720 KHz KHz % ns V mV 0.4 V V μA °C VIN IDDQ ISD VFB VOVP RDS(ON) RDS(ON) ILX(leak) ILIMIT(HS) ILIMIT(LS) 0.779 0.8 1.4 120 110 0.821 VSHDN=0V, VLX=0V Minimum Duty From Drain to Source 2.5 3 1.5 400 480 600 140 90 100 4.3 400 FOSC FOSC(short) DMAX TMIN VUVLO(Vth) VUVLO(HYS) VSHDN (L) VSHDN (H) ISHDN TSD VFB=0V VFB=0.6V VIN Rising SHDN Input Low Voltage SHDN Input High Voltage 2 VIN =2V SHDN Input Current 2 170 Thermal Shutdown Threshold (Note 2) Note 2：Not production tested.
PL5920v2.10
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PULAN TECHNOLOGY CO.,LIMITED
PL5920
Outline Information
SOT-23-6 Package (Unit: mm)
SYMBOLS UNIT DIMENSION IN MILLIME ER MIN MAX
A A1 A2 B D E E1 e 0.90 0.00 0.90 0.30 2.80 2.60 1.50 0.90 1.80 0.30 1.45 0.15 1.30 0.50 3.00 3.00 1.70 1.00 2.00 0.60
e1 L Note：Followed From JEDEC MO-178-C.
Carrier dimensions
PL5920v2.10
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