# Placement rules (derived)

| type | constraint | weight | why |
|---|---|---|---|
| fixed | J3 |  | connector (mechanical interface) |
| fixed | J2 |  | connector (mechanical interface) |
| fixed | J4 |  | connector (mechanical interface) |
| fixed | J1 |  | connector (mechanical interface) |
| fixed | J5 |  | connector (mechanical interface) |
| near | C2.1 ≤ 1.85 mm from U2.3 (pad edge to edge) | 12.0 | U2 output cap 10uF at OUT (regulator stability) |
| near | C4.1 ≤ 0.85 mm from U1.3 (pad edge to edge) | 10.0 | decoupling U1 3V3 (+3V3), 100nF |
| near | C3.1 ≤ 5.35 mm from U1.3 (pad edge to edge) | 3.0 | bulk cap on +3V3 (10uF) near U1 (anchor chosen by proximity) |
| near | C1.1 ≤ 5.35 mm from U2.1 (pad edge to edge) | 3.0 | bulk cap on +5V_LDO (4.7uF) near U2 (anchor chosen by proximity) |
| near | C6.1 ≤ 4.35 mm from J2.2 (pad edge to edge) | 4.0 | input bulk cap 10uF on VM at power entry J2 |
| near | C9.1 ≤ 4.35 mm from J2.2 (pad edge to edge) | 4.0 | input bulk cap 22uF on VM at power entry J2 |
| near | C10.1 ≤ 4.35 mm from J2.2 (pad edge to edge) | 4.0 | input bulk cap 22uF on VM at power entry J2 |
| closer | C4.1 closer to U1.3 than C3.1 | 2.0 | C4 (smaller) closer to U1.3 than C3 |
| near | C5.1 ≤ 2.0 mm from U1.8 | 5.0 | C5 (1uF) filters U1 EN (EN) |
| near | C8.1 ≤ 2.0 mm from U4.14 | 5.0 | C8 (2.2uF) filters U4 VINT (VINT) |

## Review

- **WARN** WEAK_ANCHOR C1: C1 anchored only by proximity: bulk cap on +5V_LDO (4.7uF) near U2 (anchor chosen by proximity)
- **WARN** WEAK_ANCHOR C3: C3 anchored only by proximity: bulk cap on +3V3 (10uF) near U1 (anchor chosen by proximity)
- **WARN** UNANCHORED C7: C7 (10nF) has no placement rule
- **WARN** UNANCHORED F1: F1 (0.75A PTC) has no placement rule