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SY22851FAC (SY6177FAC)

Production
Flyback Regulator with Primary Side CV/CC Control for Adapters and Chargers

Datasheet
SY22851FAC Flyback Regulator with Primary Side CV/CC Control for Adapters and Chargers Datasheet
Part number SY22851FAC
Channel(#) 1
Vin (min) (V) 18
Vin (max) (V) 75
Topology PSR flyback
Switching frequency (min)(kHz)
Switching frequency (max)(kHz) 120
Vout (min) (V) Programmable
Vout2 (min)(V)
Vout (max) (V) Programmable
Vout2 (max )(V)
Vref accuracy (±%) 1.5
Vout accuracy(±%)
Control mode Peak current mode
Duty cycle (max)(%)
Operation mode PWM/PFM
Iq (typ) (uA) 1000
Features PSR CV/CC,QR Flyback
Package SO8
Operating temperature range(°C) -40 to 125
Functional safety category
  • Integrated 200V MOSFET
  • Primary side CV/CC control eliminates the opto-coupler
  • Valley turn-on of the primary MOSFET to achieve low switching losses
  • Low start up current: 15μA typical
  • Maximum switching frequency limitation 120kHz
  • Compact package: SO8

SY22851 is a PWM controller with several features to enhance performance of Flyback converters. It integrates a 200V MOSFET to decrease physical volume. Both current and voltage regulation are achieved by primary side control technology for low cost application. To achieve higher efficiency and better EMI performance, SY22851 drives Flyback converters in the Quasi-Resonant mode.

Evaluation Board

  • 22851-9

    Photo of evaluation board

  • 22851-8

    Photo of evaluation board

EVB_SY22851FAC

The EVB_SY22851FAC is used to evaluate a PWM controller with several features to enhance performance of Flyback converters.

Technical Documentation

Title Date
Silergy_Catalog_Q2_2026 2026-06-12
SO8 2022-05-20