Preliminary Datasheet 1.0MHz, 3.5A, Synchronous Step Down DC-DC Converter AP3435 General Description Features The AP3435 is a high efficiency step-down DC-DC High Efficiency Buck Power Converter voltage converter. The chip operation is optimized Output Current: 3.5A by peak-current mode architecture with built-in Low R Internal Switches:100m (V =5V) DS(ON) IN synchronous power MOS switchers. The oscillator Adjustable Output Voltage from 0.8V to 0.9V IN and timing capacitors are all built-in providing an Wide Operating Voltage Range: 2.7V to 5.5V internal switching frequency of 1MHz that allows Built-in Power Switches for Synchronous the use of small surface mount inductors and Rectification with High Efficiency capacitors for portable product implementations. Feedback Voltage: 800mV 1.0MHz Constant Frequency Operation Thermal Shutdown Protection Integrated Soft Start (SS), Under Voltage Lock Out Low Drop-out Operation at 100% Duty Cycle (UVLO), Thermal Shutdown Detection (TSD) and No Schottky Diode Required Short Circuit Protection are designed to provide Input Over Voltage Protection reliable product applications. The device is available in adjustable output voltage Applications versions ranging from 0.8V to 0.9V IN (2.7V V 5.5V), and is able to deliver up to 3.5A. IN LCD TV Set Top Box The AP3435 is available in PSOP-8 package. Post DC-DC Voltage Regulation PDA and Notebook Computer PSOP-8 Figure 1. Package Type of AP3435 Jun. 2013 Rev. 1. 1 BCD Semiconductor Manufacturing Limited 1 Preliminary Datasheet 1.0MHz, 3.5A, Synchronous Step Down DC-DC Converter AP3435 Pin Configuration MP Package (PSOP-8) 8 1 2 7 3 6 5 4 Figure 2. Pin Configuration of AP3435 (Top View) Pin Description Pin Number Pin Name Function 1 VCC Supply input for the analog circuit 2 NC No connection 3 GND Ground pin Feedback pin. Receive the feedback voltage from a 4 FB resistive divider connected across the output Chip enable pin. Active high, internal pull-high with 5 EN 200k resistor 6 PGND Power switch ground pin 7 SW Switch output pin 8 VIN Power supply input for the MOSFET switch Jun. 2013 Rev. 1. 1 BCD Semiconductor Manufacturing Limited 2