# Waveguide Driver
## Description
Waveguide Driver - add U2 EN pull-down and U2_VOUT_NEG bleeder
## Project Details
- **Owner:** toshbeats
- **Created:** 2/2/2026
- **Last Updated:** 2/9/2026
- **Visibility:** Public
- **VIN (assumed):** 5V
- **VIN:** 3.3V
- **Passive sourcing notes:** Target: JLC/LCSC-friendly passives in 0201/0402 only. Voltage derating policy: 3.3 V <= 60% of Vrated -> Vrated >= 5.5 V (use 6.3 V min; 10 V required for LM27761 flying cap and CPOUT). Note DC-bias: 10 uF 0402 X5R/X7R may de-rate significantly; verify effective capacitance at applied bias.
- **Capacitor derating policy:** <=60% of voltage rating
- **Copies:** 5
## Key Components
### IC1 — [LM3881MMX/NOPB](https://www.flux.ai/adrian95/lm3881mmxnopb.md)
- Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Flm3881
- Manufacturer Part Number: LM3881MMX/NOPB
- Part Type: Integrated Circuit
- Manufacturer Name: Texas Instruments
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- EN [pin 2]
- FLAG1 [pin 8]
- FLAG2 [pin 7]
- FLAG3 [pin 6]
- GND [pin 3]
- INV [pin 4]
- TADJ [pin 5]
- VCC [pin 1]
### J1 — 5050701422 SPECIAL
- Part Type: Connector
- Manufacturer Name: Molex
- Manufacturer Part Number: 5050701422
**Pins:**
- CS_CHIP [pin 7]
- CS_FLASH [pin 4]
- DIO0 [pin 9]
- DIO1 [pin 13]
- DIO2 [pin 1]
- DIO3 [pin 5]
- GND [pin 10]
- GND [pin 12]
- GND [pin 14]
- P1 [pin 15]
- P1_1 [pin 17]
- P2 [pin 16]
- P2_2 [pin 18]
- PGMDB [pin 11]
- SCLK [pin 3]
- VCC2.5V [pin 6]
- WP_FLASH [pin 8]
- XIN [pin 2]
### U1 — [T55A107M6R3C0070](https://www.flux.ai/lcsc/t55a107m6r3c0070.md)
- Manufacturer Name: VISHAY(威世)
- LCSC Part Number: C3151610
- Package or Case Code: C1206
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: T55A107M6R3C0070
- Part Type: Tantalum Capacitors
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### U2 — [LM27761DSGT](https://www.flux.ai/lcsc/lm27761dsgt.md)
- Package or Case Code: WFDFN-8_L2.0-W2.0-P0.50-BL-EP
- Manufacturer Name: TI(德州仪器)
- Manufacturer Part Number: LM27761DSGT
- JLCPCB Part Class: Extended Part
- LCSC Part Number: C2070605
- Part Type: DC-DC Converters
**Pins:**
- C1- [pin 7]
- C1+ [pin 8]
- CPOUT [pin 3]
- EN [pin 6]
- GND [pin 2]
- PAD [pin 9]
- VFB [pin 5]
- VIN [pin 1]
- VOUT [pin 4]
### U6 — [ADM7155ACPZ-01-R7](https://www.flux.ai/lcsc/adm7155acpz-01-r7.md)
- Package or Case Code: LFCSP-8_L3.0-W3.0-P0.50-BL-EP-2
- LCSC Part Number: C658455
- Manufacturer Name: ADI(亚德诺)
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: ADM7155ACPZ-01-R7
**Pins:**
- BYP [pin 3]
- EN [pin 7]
- EP [pin 9]
- GND [pin 4]
- REF [pin 6]
- REF_SENSE [pin 5]
- VIN [pin 8]
- VOUT [pin 2]
- VREG [pin 1]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/toshbeats/waveguide-driver](https://www.flux.ai/toshbeats/waveguide-driver).*
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*Generated from [https://www.flux.ai/toshbeats/waveguide-driver](https://www.flux.ai/toshbeats/waveguide-driver)*