AP1520 PWM CONTROL 2A STEP-DOWN CONVERTER Description Pin Assignments AP1520 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, oscillation circuit, (Top View) error amplifier and internal PMOS. AP1520 provides low-ripple power, high efficiency and excellent Vss FB 1 8 transient characteristics. The PWM control circuit is able to vary the duty ratio linearly from 0 up to 100%. This converter also contains an Vss 2 7 EN error amplifier circuit. An enable function, an over current protection AP1520 and a short circuit protection are built inside, and when OCP or SCP 3 6 Output OCSET happens, the operation frequency will be reduced from 300kHz to 30kHz. Also, an internal compensation block is built in to minimum 4 5 external component count. VCC Output With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function SO-8 as step-down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SO-8 package, providing such outstanding features as low current consumption. Applications Since this converter can accommodate an input voltage up to 23V, it is also suitable for the operation via an AC adapter. PC Motherboard LCD Monitor Graphic Card Features DVD-Video Player Input Voltage: 3.6V to 23V Telecom Equipment Output Voltage: 0.8V to V CC ADSL Modem Duty Ratio: 0% to 100% PWM Control Printer and Other Peripheral Equipment Oscillation Frequency: 300kHz Typ Microprocessor Core Supply Current Limit, Enable Function Networking Power Supply Thermal Shutdown Function Built-in Internal SW P-channel MOS Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free.Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See AP1520 Pin Descriptions Pin Number Pin Name Description Feedback pin 1 FB Enable Input pin H: Normal operation (Step-down operation) 2 EN L: Step-down operation stopped (All circuits deactivated) Add an external resistor to set max output current 3 OCSET IC power supply pin 4 V CC Switch Pin. Connect external inductor/diode here. Minimize trace area at this pin to reduce EMI 5, 6 Output GND Pin 7, 8 V SS Functional Block Diagram Output Oscillation Reference Voltage Circuit Source with Soft Start V cc + PWM-Switched FB Control Circuit - Thermal Shutdown 100uA V Vss EN OCSET EN Absolute Maximum Ratings Symbol Parameter Rating Unit V V Pin Voltage V - 0.3 to V + 25 V CC CC SS SS FB Pin Voltage V V V - 0.3 to V FB SS CC V EN Pin Voltage V - 0.3 to V + 0.3 V EN SS IN Output Pin Voltage V V V - 0.3 to V + 0.3 OUT SS IN P Power Dissipation Internally Limited mW D Operating Junction Temperature Range -20 to +125 C T OP T Storage Temperature Range -65 to +150 C ST Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. 2 of 9 AP1520 December 2017 Diodes Incorporated www.diodes.com Document number: DS31174 Rev. 6 - 2