A20112 Power Supply Schematic

The A20112 (often referred to as R2A20112 or R2A20112ASP) is an integrated circuit (IC) primarily used as a Power Factor Correction (PFC) controller in high-efficiency switching power supplies (SMPS) . Overview of R2A20112

11. Troubleshooting Guide

• No output: check fuse, bridge, bulk cap voltage, controller Vcc/startup.
• Output low or unstable: inspect feedback network, TL431 reference, optocoupler, compensation.
• High ripple: check output caps ESR, diode conduction, switching node waveform.
• Overheating: check component sizing, airflow, shorted traces.
• EMI problems: add snubbers, relocate noisy traces, add common-mode choke.

4.7 Indicators and Connectors

Interleaved Control: It manages two power stages in parallel but out of phase. This reduces the ripple current in the output capacitors and allows for smaller, more cost-effective inductors. a20112 power supply schematic