SF6781

SF6781

TM

with Fast Dynamic Response

super-QR/PSR CV/CC Controller

FEATURES

◆ Meet EPS Level 6

◆ Fast Dynamic Response

super-QR/PSRTM (Quasi-◆ Proprietary

Resonant & Primary Side Regulation) Control for High Efficiency and Low EMI

◆ Proprietary “Zero-Output Startup” Control ◆ Proprietary “Smart Output Short Protection” ◆ Proprietary Cable Drop Compensation ◆ FB Short Protection

◆ Less than 100mW Standby Power ◆ ±5% CC and CV Precision

◆ Cycle-by-Cycle Current Limiting ◆ Leading Edge Blanking (LEB) ◆ Soft Start

◆ Output Over Voltage Protection ◆ VDD UVLO, OVP & Clamp

GENERAL DESCRIPTION

SF6781 is a high performance, highly integrated QR (Quasi Resonant Mode) and Primary Side Regulation (PSR) controller for offline small power converter applications. The IC can achieve fast dynamic response performance.

SF6781 has proprietary super-QR/PSRTM control for high efficiency and low EMI, which can ensure system to meet EPS Level 6 energy standard. The IC has proprietary “Zero-Output Startup” control to achieve startup when output is zero voltage. The IC has proprietary “Smart Output Short Protection”, which can limit maximum power when output is short. The IC also has built-in cable drop compensation function to achieve excellent CV performance.

SF6781 integrates functions and protections of FB Short Protection, Under Voltage Lockout (UVLO), VDD Over Voltage Protection (VDD OVP), Output Over Voltage Protection (Output OVP), Soft Start, Cycle-by-cycle Current Limiting (OCP), Pin Floating Protection, Gate Clamping, VDD Clamping. SF6781 is available in SOT23-6 package.

APPLICATIONS

◆ Battery chargers for cellular phones, cordless

phones, PDA, digital cameras, etc

◆ Replaces linear transformer and RCC SMPS ◆ AC/DC LED lighting

TYPICAL APPLICATION

SiFirst Confiden

tial

©SiFirst Technology - 1 - Confidential

SiFirst_DS_6781_V1.0

SF6781

Pin Configuration

GNDGATE

1SOT23-62354FBCC

6VDD

CS

Ordering Information

Part Number

Top Mark Package

Marking Information rst ConfidenSF6781LGT .81YWW SOT23-6 Green

Pin Num

1 GND P Ground 2 GATE O Totem-pole gate driver output to drive the external MOSFET. 3 CS I Current sense pin.4 CC O Connect a capacitor between this pin and GND for CC regulation. 5 FB I System feedback pin. This control input regulates both the output voltage

in CV mode and output current in CC mode based on the flyback voltage of the auxiliary winding.

6 VDD P IC power supply pin.

Si

©SiFirst Technology - 2 - Confidential

SiFirst_DS_6781_V1.0

FiPin Description

Pin Name I/O Description

tial

Tape & Reel

Yes