---
title: HBOX Watchdog v3 PROD — LCSC / JLC Assembly Parts List
project: Project Drogheda
date: 2026-07-06
status: §1 specialty parts VERIFIED against JLC live stock (2026-07-06). Passives/common semis → JLC auto-match. LCSC filled into production/HBOX_v3_PROD_bom.csv.
tags: [project-drogheda, hardware, pcb, jlcpcb, bom, lcsc]
---

# HBOX Watchdog v3 PROD — LCSC parts list (for JLC assembly)

**Quantities are per board** — JLC multiplies by your order qty (5). LCSC `C…` numbers below were
pulled from JLC's live parts search on **2026-07-06**; stock moves, so re-confirm at upload.

---

## ⚠️ Three decisions to make before ordering

1. **Inductors L2/L6/L7 — the Bourns SRU8028 are OUT OF STOCK at JLC** (pre-order only). I found
   in-stock **Sunlord MWSA0804** drop-in candidates below — but they're **8.8×8.2 mm** vs your
   footprint's **8.0×8.0 mm**. Confirm the pads overlap (they usually do for 2-pad molded 8×8s)
   before you commit, or pre-order the exact Bourns (adds weeks). The Sunlord are actually
   **higher-rated** (10 µH @6.5 A, 2.2 µH @14 A vs Bourns 2.2 A / 8 A).
2. **F1 PPTC voltage** — pick the rating for the rail F1 sits on. If it's on the **24 V** input,
   use the 24 V part; if on a **5 V / battery** node, the genuine Littelfuse 6 V is fine.
3. **MP1584EN (U2/U7)** has only **one in-stock** variant (C15051, SOIC-8-EP) — everything else is
   pre-order/consign. Fine, just don't let auto-match pick a 0-stock clone.

---

## §1 — Specialty parts — VERIFIED LCSC (live JLC, 2026-07-06)

| Ref(s) | Qty | LCSC # | MFR Part | Pkg | Type · Stock | Notes |
|---|---|---|---|---|---|---|
| **U6** | 1 | **C687163** | LTC4040EUFD#TRPBF (ADI) | QFN-24 4×5 | Ext · 2341 | The critical charger IC. |
| **U2, U7** | 2 | **C15051** | MP1584EN-LF-Z (MPS) | SOIC-8-EP | Ext · 10527 | Only in-stock variant. |
| **U3** | 1 | **C2848306** | SHT40-AD1B-R3 (Sensirion) | DFN-4 1.5×1.5 | Ext · 9534 | R2 alt: C2909890 (stock 12772). |
| **U4** | 1 | **C99269** | TMP102AIDRLR (TI) | SOT-563 | Ext · 898 | Cheaper high-stock UMW clone: C5692997 (10143). |
| **L2, L7** | 2 | **C17700171** | MWSA0804S-100MT (Sunlord) | 8.8×8.2 | Ext · 109 | 10 µH 6.5 A — **SUB** for SRU8028-100Y; verify pads. |
| **L6** | 1 | **C17700165** | MWSA0804S-2R2MT (Sunlord) | 8.8×8.2 | Ext · 261 | 2.2 µH 14 A — **SUB** for SRU8028-2R2Y; verify pads. |
| **Q10** | 1 | **C2624** | IRFR5305TRPBF (Infineon) | DPAK/TO-252 | Ext · 45808 | Genuine Infineon, huge stock. |
| **Q7** | 1 | **C35349** | AO4406AL (AOS) | SOIC-8 | Ext · 2039 | Cheap high-stock UMW: C2944312 (62071). |
| **RS1** | 1 | **C7420012** | FRM121WFR008TM (FOJAN) | 1206 | Ext · 20959 | 8 mΩ 1 W ±1% sense. Premium alt: Vishay WSLP C2076276. |
| **D10** | 1 | **C224019** | SMBJ33A (Littelfuse) | SMB DO-214AA | Ext · 28875 | Cheapest high-stock: C353366 (Jingdao). |
| **DZG** | 1 | **C80857** | BZX84C15LT1G (onsemi) | SOT-23 | Ext · 26047 | 15 V zener. |
| **F1** | 1 | **C20627123** | 1812L300/24GR (LUTE) | 1812 | Ext · 69432 | PPTC 3 A **24 V**. If node ≤6 V use genuine Littelfuse **C127824** (6 V). |
| **SW4G** | 1 | **C2689642** | PTS636SK25SMTRLFS (C&K) | SMD 6×3.5 | Ext · 7882 | Reset button. Gull-wing SMD — confirm vs footprint pads. |

---

## §2 — Common semiconductors → JLC **Basic**, let auto-match fill (search MPN to confirm)

| Ref(s) | Qty | MFR Part | Pkg |
|---|---|---|---|
| Q1 | 1 | AO3401A (P-ch) | SOT-23 |
| Q2, Q4 | 2 | AO3400A (N-ch) | SOT-23 |
| Q5, Q6 | 2 | MMBT3904 (NPN) | SOT-23 |
| D2, DBK, DBK2 | 3 | SS34 (40 V 3 A Schottky) | SMA |
| D5 | 1 | BAT54 | SOD-123 |
| D6 | 1 | 1N4148W | SOD-123 |
| D1, D4G, DB1–DB4 | 6 | LED 0805 | 0805 — pick color per function |

> These are all JLC Basic/common; on BOM upload JLC auto-suggests an in-stock part. Want me to
> fill exact LCSC #s for these too? Say the word.

---

## §3 — Resistors (0603 — auto-match, or pick any Basic)

**Standard (5%):** 1 k ×5 · 10 k ×10 · 100 k ×8 · 4.7 k ×2 · 330 R ×4 · 5.1 k ×2 · 40.2 k ×2 · 100 R ×2 · 22 k · 20 k
**Precision 1% (0603):** 19.1 k · 10 k ×2 · **825 R (R50, LTC4040 PROG)** · 287 k · 100 k ×3 · 499 k · 31.6 k

## §4 — Capacitors (auto-match; confirm voltages)

100 nF 0603 ×7 · 10 nF 0603 ×2 · 2.2 nF 0603 ×2 · 2.2 µF 0603 · 10 µF 0805 ×2 · 22 µF 0805 ×3 (≥16 V) ·
22 µF/16 V 0805 · 22 µF/50 V 1210 · 47 µF 1210 ×2 (≥25 V) · **electrolytics** 47 µF/50 V (C10), 47 µF (C3), 100 µF/6.3 V (C43) — 6.3×7.7 body, verify fit.

---

## §5 — Do NOT put on the JLC SMD BOM

**Hand-solder (THT):** Phoenix **P1** · JST **P2, P4, P5, P6, P8, P10, P11, P12** · sockets **J1, J2** (2.54) · **J7, J8** (2.0) · **MOD1** (Pro headers) · relay **K1** · tactile **SW1**.
**No part:** MH1–MH4 · TP1, TP2 · JP1–JP4.
**Modules (plug in after):** Blackpill → J1/J2 · simpleRTK2B Pro → MOD1 · 4G NTRIP Master → J7/J8.
**J9 USB-C (USB4085):** hand-solder recommended (or search `USB4085` to have JLC place it).
**DNP — drop before assembly:** **P3, P13, H3** (set the real DNP flag or delete their BOM rows; THT anyway).