A20112 Power Supply Schematic [top] Official

Note:

The designation "A20112" is most commonly associated with proprietary power supply boards used in arcade hardware (specifically Namco System 246/256 platforms used for games like Tekken 4 , Time Crisis 3 , and Soul Calibur II ). Schematics for these specific AC/DC converter units are rarely released as public service manuals, as they are treated as "replaceable units" (FRUs) by the manufacturer.

Table of Contents

While full board-level schematics are often proprietary to manufacturers like HP or Renesas, the IC's official datasheet from Renesas a20112 power supply schematic

4. Common Failure Modes & Troubleshooting

• Input cap: 100–470 µF electrolytic + 0.1 µF ceramic.
• Output cap: 100–470 µF low-ESR (or polymer) + 1 µF ceramic.
• Inductor (buck): value tuned for ripple—e.g., for 5 V, 2 A, switching 500 kHz, L ≈ 10–22 µH.
• Schottky diode for non-synchronous: low V_f, rated >I_out.
• MOSFET: R_DS(on) low enough for conduction losses < acceptable; Vds margin 1.5× Vin_max.
• Controller IC: choose by topology (e.g., buck controller with internal MOSFET for compactness).