# EPC23111 60 V / 500 W / 200 kHz Buck Reference Layout Notes

Files:
- EPC23111_Eagle63_datasheetDraft.lbr: Eagle 6.3 library with symbol, package and deviceset.
- EPC23111_reference_placement_Eagle63.scr: starter script for placement and layout notes.

Important:
This footprint is generated from the two provided PNGs. It is a high-quality draft, not a released manufacturer CAD model. Verify Gerbers against EPC pages 15/16 before fabrication.

## 2-layer placement concept

Top layer:
1. U1 EPC23111 in the center.
2. VIN-PGND MLCCs immediately above/beside pins 10 and 8. Use several 100 nF / 1 uF / 2.2 uF ceramics in parallel.
3. SW node exits pin 9 directly to the inductor. Keep this copper compact and away from PWM/EN/feedback.
4. CBOOT directly between pins 13 VBOOT and 11 VPHASE.
5. CDD directly between pins 4 VDD and 7 AGND.
6. CDRV directly between pins 5 VDRV and 7 AGND.
7. RDRV between VDRV and RDRV. Start with 10 ohm.
8. RBOOT between VBOOT and RBOOT. Start with 10 ohm.

Bottom layer:
- continuous PGND plane.
- via stitching at PGND, VIN capacitor return, and output capacitor return.
- no signal routing under SW copper.

## For your 500 W / 60 V synchronous buck
- EPC23111 is rated 80 V recommended VIN operating range and 100 V absolute max.
- Use conservative snubber/probing margin: keep VIN overshoot below about 80 V recommended, absolute never above 100 V.
- 200 kHz is far below the 3 MHz maximum PWM rating, but thermal design dominates.
- For 60 V to 24 V / 500 W, output current is about 20.8 A. Use top-side heatsinking or a large copper area.

## First-pass external values
- VDRV = 5 V.
- CDRV = 2.2 uF X7R + 100 nF close to pins.
- CDD = 100 nF close to VDD/AGND.
- CBOOT = 2.2 uF X7R close to VBOOT/VPHASE.
- RDRV = 10 ohm.
- RBOOT = 10 ohm.
- PWM series resistor from MCU = 10 to 33 ohm close to MCU or connector.
- EN and SD/STB should have defined states during MCU reset.

## Routing priority
1. VIN-PGND input loop.
2. SW-to-inductor path.
3. bootstrap loop VBOOT/RBOOT/VPHASE.
4. VDRV/VDD bypass loops.
5. logic/control signals.
