PART OBSOLETE - NO ALTERNATE PART AP1534 PWM CONTROL 2A STEP-DOWN CONVERTER Description Pin Assignments AP1534 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, (Top View) oscillation circuit, error amplifier, internal PMOS. AP1534 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to vary the 8 V 1 FB SS duty ratio linearly from 0 up to 99%. This converter also contains an error amplifier circuit as well as a soft-start circuit that prevents 2 V EN 7 SS overshoot at startup. An enable function, an over current protect AP1534 function and a short circuit protect function are built inside, and Output 6 OCSET 3 when OCP or SCP happens, the operation frequency will be reduced from 300KHz to 50KHz. Also, an internal compensation V 5 Output CC 4 block is built in to minimize external component count. With the addition of an internal P-channel Power MOS, a coil, SO-8 capacitors, and a diode connected externally, these ICs can function as step-down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SO-8 mini- packages, providing such outstanding features as low current consumption. Since this converter can accommodate an input voltage up to 18V, it is also suitable for the operation via an AC adapter. Features Applications Input voltage: 3.6V to 18V PC Motherboard Output voltage: 0.8V to V LCD Monitor CC Duty ratio: 0% to 99% PWM control Graphic Card Oscillation frequency: 300KHz typical DVD-Video Player Current limit, Enable function Telecom Equipment Thermal Shutdown function ADSL Modem Built-in internal SW P-channel MOS Printer and other Peripheral Equipment SO-8: Available in Green Molding Compound Microprocessor Core Supply (No Br, Sb) Lead Free Finish/RoHS Compliant (Note 1) For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. AP1534 Pin Descriptions Pin Name Pin No. Description FB 1 Feedback pin Power-off pin H: Normal operation EN 2 (Step-down operation) L: Step-down operation stopped (All circuits deactivated) OCSET 3 Add an external resistor to set max output current V 4 IC power supply pin CC Switch Pin. Connect external inductor/diode here. Output 5, 6 Minimize trace area at this pin to reduce EMI V 7, 8 GND Pin SS Functional Block Diagram Output Oscillation Reference Voltage Circuit Source Vcc + PWM-Switched FB Control Circuit - Thermal Shutdown 100uA V Vss EN OCSET EN Absolute Maximum Ratings Symbol Parameter Rating Unit ESD HBM Human Body Model ESD Protection 4.5 KV ESD MM Machine Model ESD Protection 150 V V VCC Pin Voltage V - 0.3 to V + 20 V CC SS SS V Feedback Pin Voltage V - 0.3 to V V FB SS CC V EN Pin Voltage V - 0.3 to V V EN SS IN V Switch Pin Voltage V - 1.0 to V V OUT SS IN P Power Dissipation Internally limited mW D o T Operating Junction Temperature Range -40 to +125 C J o 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 AP1534 March 2020 Diodes Incorporated www.diodes.com Document number: DS31314 Rev. 7 - 4 OBSOLETE PART DISCONTINUED