Features General Description

1 Datasheet 2A 150 KHz 40V Buck DC to DC Converter XL1509 Rev 1 Features Wide to 40V Input Voltage Range ,5V,12V, and adjustable versions Output Adjustable from to 37V Maximum Duty Cycle 100% Minimum Drop Out Fixed 150 KHz Switching Frequency 2A Constant Output Current Capability Internal Optimize Power Transistor High efficiency Excellent line and load regulation TTL shutdown capability ON/OFF pin with hysteresis function Built in thermal shutdown function Built in current limit function Built in second current limit function Available in SOP8 package Applications LCD Monitor and LCD TV Digital Photo Frame Set-up Box ADSL Modem Telecom / Networking Equipment General Description The

2 XL1509 is a 150 KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 2A 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. When second current limit function happens, the operation frequency will be reduced from 150 KHz to 50 KHz.

3 An internal compensation block is built in to minimize external component count. Figure1. Package Type of XL1509 Datasheet 2A 150 KHz 40V Buck DC to DC Converter XL1509 Rev 2 Pin Configurations XL150913524 GNDVINFEEDBACKOUTPUTON/OFF678

4 GNDGNDGND Figure2. Pin Configuration of XL1509 (Top View) Table 1 Pin Description Pin Number Pin Name Description 1 VIN Supply Voltage Input Pin. XL1509 operates from a to 40V DC voltage. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input. 2 OUTPUT Power Switch Output Pin (SW). Output is the switch node that supplies power to the output. 5~8 GND Ground Pin. Care must be taken in layout. This pin should be placed outside of the Schottky Diode to output capacitor ground path to prevent switching current spikes from inducing voltage noise into XL1509. 3 FEEDBACK Feedback Pin (FB).

5 Through an external resistor divider network, Feedback senses the output voltage and regulates it. The feedback threshold voltage is 4 ON/OFF Enable Pin. Drive ON/OFF pin low to turn on the device, drive it high to turn it off. Floating is default low. Datasheet 2A 150 KHz 40V Buck DC to DC Converter XL1509 Rev 3 Function Block Figure3.

6 Function Block Diagram of XL1509 Typical Application Circuit C1 105180uf 35VD1 L1 68uh/2A+12 VLOAD15~8423 GNDVINFEEDBACKOUTPUTON/OFFONOFF5V/2 ACOUT1N5820470uf 35V Figure4. XL1509 Typical Application Circuit 12V-5V/2A Datasheet 2A 150 KHz 40V Buck DC to DC Converter XL1509 Rev 4 Ordering Information Package

7 Temperature Range Marking ID Packing Type Supplied As Lead Free SOP8L -40oC ~ 85oC XL1509-ADJE1 2500 Units on Tape & Reel 2500 Units on Tape & Reel 2500 Units on Tape & Reel XL1509-12E1 2500 Units on Tape & Reel XLSEMI Pb-free products, as designated with E1 suffix in the par number, are RoHS compliant. XL1509 Circuit Type Type and Reel E1: Lead Free E1 Packing Version ADJ: Adjust : : 5V 12: 12V Datasheet 2A 150 KHz 40V Buck DC to DC Converter XL1509 Rev 5 Absolute Maximum Ratings Note1 Parameter Symbol Value Unit Input Voltage Vin to

8 45 V Feedback Pin Voltage(for the ADJ, , 5V) VFB to 7 V Feedback Pin Voltage(for the 12V) VFB to Vin V ON/OFF Pin Voltage VON/OFF to Vin V Output Switch Pin Voltage VOutput to Vin V Power Dissipation PD Internally limited mW Thermal Resistance (SOIC8) (Junction to Ambient, No Heatsink, Free Air) RJA 100 C/W Operating Junction Temperature TJ -40 to 125 C Storage Temperature TSTG -65 to 150 C Lead Temperature (Soldering, 10 sec) TLEAD 260 C ESD (HBM) 2000 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.

9 Exposure to absolute maximum rating conditions for extended periods may affect reliability. Datasheet 2A 150 KHz 40V Buck DC to DC Converter XL1509 Rev 6 Electrical Characteristics Ta = 25 C;unless otherwise specified.

10 Symbol Parameter Test Condition Min. Typ. Max. Unit System parameters test circuit figure5 VOUT Output Voltage Vin = to 40V Iload= to 2A V Efficiency Vin=12V ,Vout= Iout=2A - 75 - % Electrical Characteristics Ta = 25 C;unless otherwise specified. Symbol Parameter Test Condition Min. Typ. Max. Unit System parameters test circuit figure5 VOUT Output Voltage Vin = 7V to 40V Iload= to 2A 5 V Efficiency Vin=12V ,Vout=5V Iout=2A - 82 - % XL1509-12 Electrical Characteristics Ta = 25 C;unless otherwise specified. Symbol Parameter Test Condition Min. Typ. Max. Unit System parameters test circuit figure5 VOUT Output Voltage Vin = 15V to 40V Iload= to 2A 12 V Efficiency Vin=25V ,Vout=12V Iout=2A - 90 - % XL1509-ADJ Electrical Characteristics Ta = 25 C;unless otherwise specified.