Document
XLSEMI
5A 150KHz 36V Buck DC/DC Converter With Constant Current Loop
Datasheet XL4501
Features
n Wide 8V to 36V Input Voltage Range n Output Adjustable from 1.25V to 32V n Minimum Drop Out 0.3V n Fixed 150KHz Switching Frequency n Maximum 5A Switching Current n Internal Optimize Power MOSFET n Excellent line and load regulation n With output constant current loop n Built in thermal shutdown function n Built in current limit function n Available in TO263-5L package
Applications
n Car Charger n Battery Charger n LCD Monitor and LCD TV n Portable instrument power supply n Telecom / Networking Equipment n Buck constant current driver n Monitor LED Backlighting n General purpose LED lighting
General Description
The XL4501 is a 150KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 4.5A load with high efficiency, low ripple and excellent line and load regulation. Requiring a minimum number of external components, the regulator is simple to use and include internal frequency compensation and a fixed-frequency oscillator.
The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An enable function, an over current protection function is built inside. An internal compensation block is built in to minimize external component count.
Rev1.0
Figure1. Package Type of XL4501
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XLSEMI
5A 150KHz 36V Buck DC/DC Converter With Constant Current Loop Pin Configurations
Datasheet XL4501
Figure2. Pin Configuration of XL4501 (Top View)
Table 1 Pin Description Pin Number Pin Name 1 GND
2 FB
3 SW 4 CS
5 VIN
Description
Ground Pin. Feedback Pin (FB). Through an external resistor divider network, Feedback senses the output voltage and regulates it. The feedback threshold voltage is 1.25V. Power Switch Output Pin (SW). Output is the switch node that supplies power to the output. Output Current Sense Pin; (Iload=0.11V/Rcs) Supply Voltage Input Pin. XL4501 operates from a 8V to 36V DC voltage. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input.
Rev1.0
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XLSEMI
5A 150KHz 36V Buck DC/DC Converter With Constant Current Loop Function Block
Datasheet XL4501
Figure3. Function Block Diagram of XL4501
Typical Application Circuit
Rev1.0
Figure4. XL4501 Typical Application Circuit
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XLSEMI
5A 150KHz 36V Buck DC/DC Converter With Constant Current Loop Typical System Circuit(Buck LED Constant Current Driver)
Datasheet XL4501
Figure5. XL4501 Typical Application Circuit(LED Constant Current Driver)
Ordering Information
Package
Temperature Part Number
Range
Lead Free
Marking ID Lead Free
Packing Type
TO263-5L -40℃~ 85℃ XL4501E1
XL4501E1
800 Units Tape & Reel
XLSEMI Pb-free products, as designated with “E1” suffix in the par number, are RoHS compliant.
Absolute Maximum Ratings(Note1)
Parameter
Symbol
Value
Unit
Input Voltage
Vin -0.3 to 40 V
FB Pin Voltage SW Pin Voltage Power Dissipation Thermal Resistance(TO263-5L) (Junction to Ambient, No Heatsink, Free Air)
VFB VSW PD
RJA
-0.3 to Vin -0.3 to Vin Internally limited
30
V V mW
ºC/W
Maximum Junction Temperature Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) ESD (HBM)
TJ TJ TSTG TLEAD
-40 to 150 -40 to 125 -65 to 150
260 >2000
ºC ºC ºC ºC V
Note1: Stresses greater than those listed under Maximum Ratings may cause permanent damage
to the device. This is a stress rating only and functional operation of the device at these or any
other conditions above those indicated in the operation is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect reliability.
Rev1.0
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XLSEMI
Datasheet
5A 150KHz 36V Buck DC/DC Converter With Constant Current Loop
XL4501
XL4501 Electrical Characteristics
Ta = 25℃;unless otherwise specified.
Symbol Parameter
Test Condition
System parameters test circuit figure4
VFB Efficiency
Feedback Voltage
ŋ
Vin = 8V to 36V, Vout=5V Iload=0.2A to 4A Vin=12V ,Vout=5V Iout=4A
Min. Typ. Max. Unit
1.231 1.25 1.269 V - 86 - %
Electrical Characteristics (DC Parameters)
Vin = 12V, GND=0V, Vin & GND parallel connect a 100uF/50V capacitor; Iout=500mA, Ta = 25℃; the others floating unless otherwise specified.
Parameters
Symbol Test Condition Min. Typ. Max. Unit
VIN operation voltage
Vin
8 36 V
VIN UVLO
Vuvlo
5V
Quiescent Supply Current
Iq
VFB =Vin
2 5 mA
Oscillator Frequency
Fosc
127 150 172 KHz
Switch Current Limit
IL
Output Power PMOS
Rdson
Constant current sense Voltage
VCS
VFB =0
VFB=0V, Vin=12V, ISW=5A
104.5
7A 75 100 mohm 110 115.5 mV
Rev1.0
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XLSEMI
5A 150KHz 36V Buck DC/DC Converter With Constant Current Loop Typical System Application (Car Charger)
Datasheet XL4501
Figure6. XL4501 System Parameters Test Circuit (VIN=8V~36V, VOUT=5V/0.1A~4.2A)
Output voltage(V)
Output voltage VS Output current
5.5
5.0
4.5
4.0
3.5
3.0 VIN=8V,VOUT=5V,IOUT=0.1A~4.2A
2.5
VIN=12V,VOUT=5V.