AP3785T PRIMARY SIDE REGULATED SWITCHING MODE POWER SUPPLY CONTROLLER Description Pin Assignments The AP3785T is a high performance AC/DC power supply controller for battery charger and adapter applications. It can meet less than (Top View) 10mW standby power for Super Star charger criteria. The device uses Pulse Frequency Modulation (PFM) method to build discontinuous conduction mode (DCM) flyback power supplies. 1 8 FB CS The AP3785T provides accurate constant voltage (CV), constant 7 CBC EM 2 current (CC) and outstanding dynamic performance without requiring an opto-coupler. It also eliminates the need of loop compensation 3 6 OTP VCC circuitry while maintaining stability. GND 4 5 OUT The AP3785T is equipped with both cable drop compensation function to meet various cables with different lengths and gauges and SO-8 adjustable line voltage compensation function. When AP3785T is used with AP4341 or synchronous rectifier series (for example APR343 + MOSFET, APR3415, APR34330), better Features under-shoot performance and higher conversion efficiency can be Primary Side Control for Eliminating Opto-coupler achieved. 10mW No-load Input Power Flyback Topology in DCM Operation The AP3785T has internal over temperature protection for itself, and External Adjustable Line Compensation for CC also provides dedicated pin for external over temperature protection. External Adjustable Cable Compensation for CV This IC is available in SO-8 package. Multiple PWM/PFM Control Mode to Improve Audio Noise and Efficiency V Jitter to Reduce System EMI CS Valley-on for the Higher Efficiency and Better EMI Multiple Protections: Applications Over Voltage Protection (OVP) Adapter/Chargers for Shaver, Cell/Cordless Phones, PDAs, MP3 Output Short Circuit Protection (SCP) and Other Portable Apparatus Transformer Saturation Protection (TSP) via Primary Peak Standby and Auxiliary Power Supplies Current Limitation OTP and External Over Temperature Protection (OTP) Matching AP4341 with Schottky or APR343/APR3415 Synchronous Rectifier Solution SO-8 Package 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 AP3785T Typical Applications Circuit (Note 4) FR1 L1 TR1 D8 C4 R9 R1 D1,D2, D3,D4 C1 C2 R11 R12 D7 + + + + R10 C5 C6 OUT VCC GND IC2 AP4341 R2 L2 V O D6 R7 C3 Q1 IC1 R8 AP3785T CY1 D5 VCC R5 OTP OUT CBC FB EM GND CS NTC1 R6 R4 R3 With Schottky (V =5V/1A or 2A) OUT FR1 L1 T1 C4 R9 R1 D1,D2, D3,D4 C1 C2 C9 R14 + + D7 + + C5 C6 R10 R2 Q2 L2 R12 D6 R7 C7 C3 Q1 IC2 IC1 AP3785T R8 D5 R13 VCC R5 OTP OUT APR343 CBC FB R11 EM GND CS NTC1 R6 R4 C8 R3 CY1 With Synchronous Rectifier (V =5V/2A) OUT 2 of 18 AP3785T September 2015 Diodes Incorporated www.diodes.com Document number: DS37552 Rev. 4 - 2 NEW PRODUCT DRISR VDET GND VCC AREF