BQ25185 Charger Topology
Worked for 1 min 28 sec
Verificación preliminar confirma que AIRTAG_CHG_SYS contiene sólo U3.SYS y C5.P1, y que CE está en AIRTAG_PACK_NEG/GND, no en SYS; ahora cierro reporte y ERC/lista de errores.
Thought for 5 sec
Detecté un error real: U4.V− estaba flotante; lo corrijo conectándolo al resistor R8 como red V− de BQ29700. Mantendré PS/SYNC de U8 como decisión abierta, no lo ataré arbitrariamente.
Worked for 50 sec
Corrección U4.V− aplicada; ejecuto la verificación final de Fase 1 y actualizaré el reporte del proyecto.
Worked for 5 mins 22 sec
Fase 1 quedó ejecutada y detenida: construí el esquema sombra por bloques, sin crear PCB, placement físico, routing, antena ni conexiones a máquina/carga. Verifiqué que AIRTAG_CHG_SYS = U3.SYS + C5.1 solamente, y que U3.CE está a AIRTAG_PACK_NEG/GND, no a SYS.
Actualicé el reporte completo con BOM, conectividad, tabla pin-a-pin BQ25185, huecos de librería, ERC y decisiones abiertas: Shadow Build Report — Brand NewDay.
Quedan errores ERC intencionales/abiertos de Fase 1: U8 PS/SYNC sin política, AIRTAG_CELL_POS sin fuente/batería definida, RF abierto sin antena/matching, y redes LM5069 UVLO/OVLO/TIMER/PWRSET sin valores.
Fix ERC and gaps
Replace proxy parts
Review schematic only
Set PS/SYNC policy
Prepare Phase 2 plan
Refine this doc
Ask about this doc
Project Specification — Brand NewDay Flux Shadow PCB
Project Overview
Clean-room shadow reconstruction in Flux for the Brand NewDay system. Status: BENCH_ONLY / NOT FOR FABRICATION / NOT FOR ENERGIZATION.
Intended Use
Architecture, schematic, and PCB-placement/routing capability evaluation only. This project must not be treated as a fabrication release, equipment authorization, RF/impedance certification, DFM approval, or permission to overwrite KiCad candidates.
Non-Negotiable Source Constraints
- Authoritative input:
Brand_NewDay_Flux_Shadow_PCB_Brief_v1.txtplusBrand_NewDay_Flux_Shadow_Agent_Instruction_v1.txt. - Do not import, modify, overwrite, or claim to reproduce KiCad N039/N040/N041.
- Use exact MPN/value/reference-designator intent from the brief wherever available.
- Maximum starting envelope: 170 mm × 140 mm, 4 layers.
- Smaller board only after placement/clearance/thermal/relay/antenna/connector/service constraints are justified.
Main Features / Functional Blocks
- USB-C service input, USB ESD protection, CC resistors, CP2102N USB-UART bridge.
- BQ25185DLHR single-cell charger/power-path, BQ29700 protection, TPS63030 buck-boost.
- LM5069 + Q1 protected power entry, LM5164 5 V buck, TPS7A2033 3.3 V logic rail.
- CC1354P106 radio/controller, UART, SPI, reset, RF interfaces/keepouts.
- MCP41HV51 digital potentiometer.
- Three 5 V relay channels with MOSFET drivers, flyback diodes, gate resistors, and gate-bias resistors.
- Q2/Q3 experimental AirTag MOSFET paths: DNP / BENCH_ONLY only.
Critical BQ25185 Correction
Official BQ25185DLH/WSON-10 mapping required by the brief:
Table
| Pin | Function | Required handling |
|---|---|---|
| U3.1 | SYS | Belongs to SYS node only. |
| U3.2 | BAT | Battery-positive / cell-positive node per brief. |
| U3.3 | STAT2 | Status output; not SYS. |
| U3.4 | CE | Active-low charge enable; must connect to GND for this shadow build. Never connect to SYS. |
| U3.5 | GND | Ground / pack-negative side per brief. |
| U3.6 | TS/MR | Support network via R25 per brief. |
| U3.7 | ILIM/VSET | Programming network via R6 per brief. |
| U3.8 | ISET | Programming network via R7 and C3 per brief. |
| U3.9 | STAT1 | Status output; not SYS. |
| U3.10 | IN | AIRTAG_CHG_5V input. |
| U3.11 | Exposed pad | AIRTAG_PACK_NEG/GND. |
C5 / SYS Capacitor Requirement
- C5 = 10 µF, 25 V, 0805, SYS capacitor.
- Connect C5 from SYS to GND close to U3.
- Datasheet requirement recorded from brief: at least 10 µF ceramic nominal and at least 1 µF effective after DC-bias derating, from SYS to GND, close to SYS/GND pins.
- Do not connect CE to C5/SYS.
Verified Connectivity Ledger From Brief
USB Service
- USB_VBUS_RAW: J1 A4/A9/B4/B9.
- USB_CC1: J1 A5 to U1.4; USB_CC2: J1 B5 to U1.5; R1/R2 are 5.1 kΩ Rd resistors.
- USB_D_P: J1 A6/B6, U1.1, U2.4.
- USB_D_N: J1 A7/B7, U1.2, U2.5.
- DGND_SERVICE includes J1 shields/grounds, U1, U2, logic/power grounds, and U9 exposed pad.
- USB_UART_TXD_MCU_RX: U2.26 to U9.11.
- USB_UART_RXD_MCU_TX: U2.25 to U9.10.
BQ25185 / Battery / AirTag
- AIRTAG_CHG_5V: U3.10 (IN).
- AIRTAG_CELL_POS: U3.2 (BAT), U4.5, U8.5/U8.6/U8.8.
- AIRTAG_CELL_NEG: U4.4 and battery-side support parts.
- AIRTAG_PACK_NEG: U3.5, U3.11 exposed pad, U8 ground pins.
- AIRTAG_3V0: U8.1 output.
- AIRTAG_BUCK_L1: U8.4 to L2.1.
- AIRTAG_BUCK_L2: U8.2 to L2.2.
- AIRTAG_FB: U8.10.
- BQ25185_ISET_PROG: U3.8.
- BQ25185_TS_MR: U3.6.
- BQ25185_VSET_PROG: U3.7.
Power Input / 5 V
- VIN_RAW: U6.2.
- VIN_SENSE: U6.1.
- VIN_PROTECTED: U6.9 to U7.2.
- MACHINE_POWER_GOOD: U6.8, U7.3, U7.6.
- LM5069 control: U6.3 UVLO, U6.4 OVLO, U6.6 TIMER, U6.7 PWRSET, U6.10 Q_HS1_GATE.
- LM5164: U7.4 RON, U7.5 FB, U7.7 BST, U7.8 SW.
- RX_5V: K1.5, K2.5, K3.5, U5.1/U5.3.
CC1354 / Digital
- RX_3V3: U2.6/U2.7, U5.5, U9.13/U9.22/U9.34/U9.44, U10.1.
- MCP_SPI_SCK: U9.12 to U10.2.
- MCP_SPI_CS_N: U9.14 to U10.3.
- MCP_SPI_MOSI: U9.15 to U10.4.
- MCP_SPI_MISO: U9.16 to U10.5.
- MCP_SHDN_SAFE_N: U10.7.
- CC1354_RESET_N: U9.35.
- CC1354_DCOUPL: U9.23.
- CC1354_VDDR: U9.45/U9.48.
- RF915_N/P: U9.4/U9.3.
- RF_PA20_N/P: U9.6/U9.5.
Relay Channels
- RELAY_K1_DRIVE: U9.26; RELAY_K1_COIL_NEG: K1.4; RX_5V: K1.5.
- RELAY_K2_DRIVE: U9.27; RELAY_K2_COIL_NEG: K2.4; RX_5V: K2.5.
- RELAY_K3_DRIVE: U9.28; RELAY_K3_COIL_NEG: K3.4; RX_5V: K3.5.
- Relay contact pins K1/K2/K3 pads 1/2/3 intentionally unresolved external contacts; do not invent machine/load wiring.
Layout Requirements
- 4 layers; do not claim controlled impedance without manufacturer stack-up.
- USB-C, ESD, CC resistors, CP2102N as one service cluster.
- BQ25185/C4/C5/C6/programming network compact; minimize SYS/GND loop.
- LM5164/L1/C10/C11/C12 compact and isolated from RF/USB.
- RF/antenna interfaces and keepout reserved; do not invent antenna geometry.
- Relays/flyback/MOSFET drivers/high-current paths away from RF/control paths.
- Ordinary through vias only; no microvias/HDI.
- Do not relax DRC or rules to hide errors.
Open Decisions / Data Not To Assume
- Battery chemistry, capacity, protection arrangement, max charge voltage, allowed charge current.
- USB role/current contract beyond basic USB-C sink Rd intent, connector/ESD requirements.
- High-voltage input range and load current for LM5069/LM5164 path.
- Machine/load wiring for relay contacts.
- RF band, antenna part/geometry, matching network, keepout, compliance target.
- Final manufacturer stack-up, copper weight, dielectric data, impedance requirements, creepage/clearance, DFM capability.
- Environmental, thermal, enclosure, mounting, connector access, and test-point requirements.
Acceptance Criteria
- Distinguish verified facts from assumptions.
- U3.4/CE separate from SYS and tied to GND for this shadow build.
- Q2/Q3 preserved as DNP/BENCH_ONLY.
- Relay contacts pins 1/2/3 not connected to real load/machine nets.
- Return missing inputs before claiming complete/fabricable design.
- Final status: BENCH_ONLY / NOT FOR FABRICATION / NOT FOR ENERGIZATION.
Change Notes
- Created from attached v1 brief and agent instruction on 2026-07-27.
Project Overview
Intended Use
Non-Negotiable Source Constraints
Main Features / Functional Blocks
Critical BQ25185 Correction
C5 / SYS Capacitor Requirement
Verified Connectivity Ledger From Brief
USB Service
BQ25185 / Battery / AirTag
Power Input / 5 V
CC1354 / Digital
Relay Channels
Layout Requirements
Open Decisions / Data Not To Assume
Acceptance Criteria
Change Notes
