Multi-Mode Primary Side Regulation (PSR)/QR-Buck CV/CC Power Switch

General Description

KP2122 is a family of a high performance Primary Side Regulation (PSR) power switch with high precision CV/CC control ideal for charger applications. The IC can also support Quasi-Resonant (QR) Buck CC&CV topology for LED lighting if SEL pin is short to GND.

In CV mode, KP2122 adopts Multi Mode Control which uses the hybrid of AM (Amplitude Modulation) mode and (Frequency Modulation) FM mode to improve system efficiency and reliability. In CC mode, the IC uses PFM control with line and load CC compensation. The IC can achieve audio noise free operation and optimized dynamic response. The built-in Cable Drop Compensation (CDC) function can provide excellent CV performance.

KP2122 integrates functions and protections of Under Voltage Lockout (UVLO), VDD over Voltage Protection (VDD OVP), Cycle-by-cycle Current Limiting (OCP), Short Load Protection (SLP), and VDD Clamping.


l   Integrated with 650V MOSFET

l   Support Flyback and Buck Topology:

n  Flyback PSR Control (SEL= Floating)

n  QR-Buck Control (SEL= GND)

l   Multi Mode PSR Control

l   Audio Noise Free Operation for PSR

l   Optimized Dynamic Response for PSR

l   Low Standby Power <70mW

l   ±4% CC and CV Regulation

l   Programmable Cable Drop Compensation (CDC) in PSR CV Mode

l   Built-in AC Line & Load CC Compensation

l   Build in Protections:

n  Short Load Protection (SLP)

n  On-Chip Thermal Shutdown (OTP)

n  Cycle-by-Cycle Current Limiting

n  Leading Edge Blanking (LEB)

n  Pin Floating Protection

n  VDD UVLO, OVP & Clamp

l   Available with SOP-7 and DIP-8 Package


l   Battery Chargers for Cellular Phones

l   AC/DC Power Adapter and LED Lightings

Pin Configuration

Typical Application Circuit

  • Charger Application
  • Intelligent LED Lighting Application

Ordering Information

Part Number



SOP-7,Halogen free in T&R, 4000Pcs/Reel


DIP-8, Pb free, 50Pcs/Tube