# Voltage-domain ERC — valve-ecu

0 error(s), 1 warning(s). Ambient 85 °C. Specs: `specs/parts/`.

## Findings

| sev | code | where | detail |
|---|---|---|---|
| WARN | THERMAL | U4 | Tj 111 °C within 15 °C of 125 °C (P 290 mW) |
| INFO | INPUT_MAX | U1.12 | PA4 on AIN1_S reaches 3.6 V > operating max 3.53 V (VDD+0.3)  [waived: PA4 (AIN1_S) reaches 3.6 V only with AIN1 shorted to battery: the BAT54WS clamp to +3V3 holds it 0.07 V over the operating max and 0.4 V under the 4.0 V abs max; the 0-5 V sensor range is 0-3.13 V] |

## Rails (power budget)

| rail | source | V | load mA | rated mA | use | nets |
|---|---|---|---|---|---|---|
| +3V3 | U4 | 3.23..3.37 | 125.7 | 800 | 16 % | +3V3 |
| +5V | U3 (R4=52300 / R5=10000) | 4.83..5.13 | 225.7 | 3500 | 6 % | +5V, SW |
| KL30 | external | 6..38.9 | 0.0 | - |  | KL30 |
| VPROT | external | 5.9..38.9 | 214.0 | - |  | VPROT |

### Loads

| rail | net | ref.pin | mA |
|---|---|---|---|
| +3V3 | +3V3 | U2.5 | 0.30 |
| +3V3 | +3V3 | U1.1 | 0.00 |
| +3V3 | +3V3 | U1.20 | 1.40 |
| +3V3 | +3V3 | U1.21 | 20.00 |
| +3V3 | +3V3 | U1.24 | 99.00 |
| +3V3 | +3V3 | J2.3 | 5.00 |
| +5V | +5V | U5.6 | 10.00 |
| +5V | +5V | U6.6 | 10.00 |
| +5V | +5V | U2.3 | 70.00 |
| +5V | +5V | U4.in | 135.70 |
| VPROT | VPROT | U3.2 | 0.50 |
| VPROT | VPROT | U3.in | 213.46 |

### Beads / series inductors

| ref | from | to | mA | DCR Ω | drop mV | rated mA |
|---|---|---|---|---|---|---|
| L1 | +5V | SW | 0.0 | 0 | 0.0 | - |

## Thermal budget

| ref | part | P mW | basis | θJA °C/W | Tj °C | limit °C | |
|---|---|---|---|---|---|---|---|
| U1 | STM32G474CBT3 | 405 | Σ V·I_max of supply pins | 55.2 | 107 | 130 | ok |
| U2 | TCAN1044VDRQ1 | 360 | Σ V·I_max of supply pins | 128.1 | 131 | 150 | ok |
| U3 | TPS54360DDAR | 101 | 1159 mW out @ η 0.92 | 42 | 89 | 150 | ok |
| U4 | AMS1117-3.3 | 290 | (5.13-3.23) V x 126 mA | 90 | 111 | 125 | WARN |
| U5 | UCC27524AQDRQ1 | 51 | Σ V·I_max of supply pins | 126.4 | 91 | 140 | ok |
| U6 | UCC27524AQDRQ1 | 51 | Σ V·I_max of supply pins | 126.4 | 91 | 140 | ok |

## Power out through connectors

Regulator outputs that leave the board (declared in erc.yaml `connector_loads`; the regulator's total capacity is the lower of its rating and its thermal limit at the worst-case input and ambient).

| pin | rail | source | declared mA | rated mA | thermal mA | board's own mA | left mA | |
|---|---|---|---|---|---|---|---|---|
| J2.3 (Pin_3) | +3V3 | U4 | 5 | 800 | 207 | 121 | 86 | STDC14 T_VCC: only a sense input for the STLINK-V3 |

## Per-pin table

| ref | pin | name | type | net | V | limit | status |
|---|---|---|---|---|---|---|---|
| D1 | 1 | K | passive | VPROT | 5.9..38.9 |  | ok |
| D1 | 2 | A | passive | GND | 0 |  | ok |
| D2 | 1 | K | passive | VPROT | 5.9..38.9 |  | ok |
| D2 | 2 | A | passive | OUT1 | 0..3.37 |  | ok |
| D3 | 1 | K | passive | VPROT | 5.9..38.9 |  | ok |
| D3 | 2 | A | passive | OUT2 | 0..3.37 |  | ok |
| D4 | 1 | K | passive | VPROT | 5.9..38.9 |  | ok |
| D4 | 2 | A | passive | OUT3 | 0..3.37 |  | ok |
| D5 | 1 | K | passive | VPROT | 5.9..38.9 |  | ok |
| D5 | 2 | A | passive | OUT4 | 0..3.37 |  | ok |
| D6 | 1 | K | passive | SW | 4.83..5.13 |  | ok |
| D6 | 2 | A | passive | GND | 0 |  | ok |
| D7 | 1 | K | passive | +3V3 | 3.23..3.37 |  | ok |
| D7 | 2 | A | passive | AIN1_S | 0..3.6 |  | ok |
| D8 | 1 | K | passive | GND | 0 |  | ok |
| D8 | 2 | A | passive | LED_A | 0..3.37 |  | ok |
| J1 | 1 | 1 | passive | KL30 | 6..38.9 |  | ok |
| J1 | 2 | 2 | passive | GND | 0 |  | ok |
| J1 | 3 | 3 | passive | OUT1 | 0..3.37 |  | ok |
| J1 | 4 | 4 | passive | OUT3 | 0..3.37 |  | ok |
| J1 | 5 | 5 | passive | CAN_H | -27..40 |  | ok |
| J1 | 6 | 6 | passive | KL15 | 0..38.9 |  | ok |
| J1 | 7 | 7 | passive | AIN1 | 0..38.9 |  | ok |
| J1 | 8 | 8 | passive | CAN_L | -27..40 |  | ok |
| J1 | 9 | 9 | passive | OUT4 | 0..3.37 |  | ok |
| J1 | 10 | 10 | passive | OUT2 | 0..3.37 |  | ok |
| J1 | 11 | 11 | passive | GND | 0 |  | ok |
| J1 | 12 | 12 | passive | KL30 | 6..38.9 |  | ok |
| J2 | 1 | Pin_1 | passive | - | ? |  | nc |
| J2 | 2 | Pin_2 | passive | - | ? |  | nc |
| J2 | 3 | Pin_3 | passive | +3V3 | 3.23..3.37 |  | ok |
| J2 | 4 | Pin_4 | passive | SWDIO | 0..3.37 |  | ok |
| J2 | 5 | Pin_5 | passive | GND | 0 |  | ok |
| J2 | 6 | Pin_6 | passive | SWCLK | 0..3.37 |  | ok |
| J2 | 7 | Pin_7 | passive | GND | 0 |  | ok |
| J2 | 8 | Pin_8 | passive | SWO | 0..3.37 |  | ok |
| J2 | 9 | Pin_9 | passive | - | ? |  | nc |
| J2 | 10 | Pin_10 | passive | - | ? |  | nc |
| J2 | 11 | Pin_11 | passive | GND | 0 |  | ok |
| J2 | 12 | Pin_12 | passive | NRST | 0..3.37 |  | ok |
| J2 | 13 | Pin_13 | passive | VCP_RX | 0..3.37 |  | ok |
| J2 | 14 | Pin_14 | passive | VCP_TX | 0..3.37 |  | ok |
| Q1 | 1 | S | passive | VPROT | 5.9..38.9 |  | ok |
| Q1 | 2 | S | passive | VPROT | 5.9..38.9 |  | ok |
| Q1 | 3 | S | passive | VPROT | 5.9..38.9 |  | ok |
| Q1 | 4 | G | passive | RPG | 0..38.9 |  | ok |
| Q1 | 5 | D | passive | KL30 | 6..38.9 |  | ok |
| Q1 | 6 | D | passive | KL30 | 6..38.9 |  | ok |
| Q1 | 7 | D | passive | KL30 | 6..38.9 |  | ok |
| Q1 | 8 | D | passive | KL30 | 6..38.9 |  | ok |
| Q1 | 9 | D | passive | KL30 | 6..38.9 |  | ok |
| Q2 | 1 | S | passive | GND | 0 |  | ok |
| Q2 | 2 | S | passive | GND | 0 |  | ok |
| Q2 | 3 | S | passive | GND | 0 |  | ok |
| Q2 | 4 | G | passive | G1 | 0..5.13 |  | ok |
| Q2 | 5 | D | passive | OUT1 | 0..3.37 |  | ok |
| Q3 | 1 | S | passive | GND | 0 |  | ok |
| Q3 | 2 | S | passive | GND | 0 |  | ok |
| Q3 | 3 | S | passive | GND | 0 |  | ok |
| Q3 | 4 | G | passive | G2 | 0..5.13 |  | ok |
| Q3 | 5 | D | passive | OUT2 | 0..3.37 |  | ok |
| Q4 | 1 | S | passive | GND | 0 |  | ok |
| Q4 | 2 | S | passive | GND | 0 |  | ok |
| Q4 | 3 | S | passive | GND | 0 |  | ok |
| Q4 | 4 | G | passive | G3 | 0..5.13 |  | ok |
| Q4 | 5 | D | passive | OUT3 | 0..3.37 |  | ok |
| Q5 | 1 | S | passive | GND | 0 |  | ok |
| Q5 | 2 | S | passive | GND | 0 |  | ok |
| Q5 | 3 | S | passive | GND | 0 |  | ok |
| Q5 | 4 | G | passive | G4 | 0..5.13 |  | ok |
| Q5 | 5 | D | passive | OUT4 | 0..3.37 |  | ok |
| U1 | 1 | VBAT | supply | +3V3 | 3.23..3.37 | min 1.55 max 3.6 abs 4 | ok |
| U1 | 2 | PC13 | io | LED | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 3 | PC14-OSC32_IN | io | - | ? |  | nc |
| U1 | 4 | PC15-OSC32_OUT | io | - | ? |  | nc |
| U1 | 5 | PF0-OSC_IN | io | OSC_IN | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 6 | PF1-OSC_OUT | io | OSC_OUT | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 7 | PG10-NRST | io | NRST | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 8 | PA0 | io | OUT1_FB | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 9 | PA1 | io | OUT2_FB | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 10 | PA2 | io | OUT3_FB | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 11 | PA3 | io | OUT4_FB | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 12 | PA4 | io | AIN1_S | 0..3.6 | max 3.53 abs 4 | ERROR |
| U1 | 13 | PA5 | io | KL15_S | 0..2.99 | max 3.53 abs 4 | ok |
| U1 | 14 | PA6 | io | PWM1 | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 15 | PA7 | io | PWM2 | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 16 | PB0 | io | PWM3 | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 17 | PB1 | io | PWM4 | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 18 | PB2 | io | VBAT_S | 0..2.99 | max 3.53 abs 4 | ok |
| U1 | 19 | VSSA | ground | GND | 0 |  | ok |
| U1 | 20 | VREF+ | supply | +3V3 | 3.23..3.37 | min 1.62 max 3.37 abs 3.77 | ok |
| U1 | 21 | VDDA | supply | +3V3 | 3.23..3.37 | min 1.62 max 3.6 abs 4 | ok |
| U1 | 22 | PB10 | io | - | ? |  | nc |
| U1 | 23 | VSS | ground | GND | 0 |  | ok |
| U1 | 24 | VDD | supply | +3V3 | 3.23..3.37 | min 1.71 max 3.6 abs 4 | ok |
| U1 | 25 | PB11 | io | - | ? |  | nc |
| U1 | 26 | PB12 | io | DRV_EN | 0..3.37 | max 3.53 abs 4 | ok |
| U1 | 27 | PB13 | io | - | ? |  | nc |
| U1 | 28 | PB14 | io | - | ? |  | nc |
| U1 | 29 | PB15 | io | - | ? |  | nc |
| U1 | 30 | PA8 | io | - | ? |  | nc |
| U1 | 31 | PA9 | io | VCP_TX | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 32 | PA10 | io | VCP_RX | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 33 | PA11 | io | CAN_RX | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 34 | PA12 | io | CAN_TX | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 35 | VSS | ground | GND | 0 |  | ok |
| U1 | 36 | VDD | supply | +3V3 | 3.23..3.37 | min 1.71 max 3.6 abs 4 | ok |
| U1 | 37 | PA13 | io | SWDIO | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 38 | PA14 | io | SWCLK | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 39 | PA15 | io | - | ? |  | nc |
| U1 | 40 | PB3 | io | SWO | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 41 | PB4 | io | - | ? |  | nc |
| U1 | 42 | PB5 | io | CAN_STB | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 43 | PB6 | io | - | ? |  | nc |
| U1 | 44 | PB7 | io | - | ? |  | nc |
| U1 | 45 | PB8-BOOT0 | io | BOOT0 | 0..3.37 | max 5.5 abs 5.8 | ok |
| U1 | 46 | PB9 | io | - | ? |  | nc |
| U1 | 47 | VSS | ground | GND | 0 |  | ok |
| U1 | 48 | VDD | supply | +3V3 | 3.23..3.37 | min 1.71 max 3.6 abs 4 | ok |
| U2 | 1 | TXD | input | CAN_TX | 0..3.37 | max 3.53 abs 6 | ok |
| U2 | 2 | GND | ground | GND | 0 |  | ok |
| U2 | 3 | VCC | supply | +5V | 4.83..5.13 | min 4.5 max 5.5 abs 6 | ok |
| U2 | 4 | RXD | output | CAN_RX | 0..3.37 |  | ok |
| U2 | 5 | VIO | supply | +3V3 | 3.23..3.37 | min 1.7 max 5.5 abs 6 | ok |
| U2 | 6 | CANL | bus | CAN_L | -27..40 |  | ok |
| U2 | 7 | CANH | bus | CAN_H | -27..40 |  | ok |
| U2 | 8 | STB | input | CAN_STB | 0..3.37 | max 3.53 abs 6 | ok |
| U3 | 1 | BOOT | passive | BOOT | ? |  | ok |
| U3 | 2 | VIN | supply | VPROT | 5.9..38.9 | min 4.5 max 60 abs 65 | ok |
| U3 | 3 | EN | input | - | ? |  | nc |
| U3 | 4 | RT/CLK | passive | RT | 0 |  | ok |
| U3 | 5 | FB | passive | FB | 0..5.13 |  | ok |
| U3 | 6 | COMP | passive | COMP | ? |  | ok |
| U3 | 7 | GND | ground | GND | 0 |  | ok |
| U3 | 8 | SW | passive | SW | 4.83..5.13 |  | ok |
| U3 | 9 | PowerPad | ground | GND | 0 |  | ok |
| U4 | 1 | GND | ground | GND | 0 |  | ok |
| U4 | 2 | VOUT | supply_out | +3V3 | 3.23..3.37 |  | ok |
| U4 | 3 | VIN | supply | +5V | 4.83..5.13 | min 4.8 max 15 abs 15 | ok |
| U4 | 4 | TAB | passive | +3V3 | 3.23..3.37 |  | ok |
| U5 | 1 | ENA | input | DRV_EN | 0..3.37 | max 18 abs 20 | ok |
| U5 | 2 | INA | input | PWM1 | 0..3.37 | max 18 abs 20 | ok |
| U5 | 3 | GND | ground | GND | 0 |  | ok |
| U5 | 4 | INB | input | PWM2 | 0..3.37 | max 18 abs 20 | ok |
| U5 | 5 | OUTB | output | GDRV2 | 0..5.13 |  | ok |
| U5 | 6 | VDD | supply | +5V | 4.83..5.13 | min 4.5 max 18 abs 20 | ok |
| U5 | 7 | OUTA | output | GDRV1 | 0..5.13 |  | ok |
| U5 | 8 | ENB | input | DRV_EN | 0..3.37 | max 18 abs 20 | ok |
| U6 | 1 | ENA | input | DRV_EN | 0..3.37 | max 18 abs 20 | ok |
| U6 | 2 | INA | input | PWM3 | 0..3.37 | max 18 abs 20 | ok |
| U6 | 3 | GND | ground | GND | 0 |  | ok |
| U6 | 4 | INB | input | PWM4 | 0..3.37 | max 18 abs 20 | ok |
| U6 | 5 | OUTB | output | GDRV4 | 0..5.13 |  | ok |
| U6 | 6 | VDD | supply | +5V | 4.83..5.13 | min 4.5 max 18 abs 20 | ok |
| U6 | 7 | OUTA | output | GDRV3 | 0..5.13 |  | ok |
| U6 | 8 | ENB | input | DRV_EN | 0..3.37 | max 18 abs 20 | ok |
| Y1 | 1 | OSC1 | passive | OSC_IN | 0..3.37 |  | ok |
| Y1 | 2 | GND | ground | GND | 0 |  | ok |
| Y1 | 3 | OSC2 | passive | OSC_OUT | 0..3.37 |  | ok |
| Y1 | 4 | GND | ground | GND | 0 |  | ok |

## Spec sources

- `examples/valve-ecu/specs/SMBJ24A.yaml` (SMBJ24A): research/SMBJ24A.pdf (sha256 95385273b500...), MDD SMBJ5.0(C)A - SMBJ440(C)A 600 W TVS
- `examples/valve-ecu/specs/SS56B.yaml` (SS56B): research/SS56B.pdf (sha256 9b14cccd6d43...), MDD SS52B-SS5200B Schottky rectifier, DO-214AA
- `specs/parts/BAT54WS.yaml` (BAT54WS-7-F): https://datasheet.lcsc.com/datasheet/pdf/ae1de730e539e7c2ce35366c970d58e6.pdf?productCode=C124205 (sha256 a910241faa21...), Diodes BAT54WS surface mount Schottky barrier diode
- `examples/valve-ecu/specs/KT-0603G.yaml` (KT-0603G): research/KT-0603G.pdf (sha256 770831ccd4b3...), Hubei KENTO KT-0603G spec for approval rev A.0 (LCSC C12624): Absolute Maximum Ratings, Electrical Optical Characteristics
- `examples/valve-ecu/specs/DTM13-12PB.yaml` (DTM13-12PB): research/DTM13-12PB.pdf (sha256 295a19396408...), TE C-DTM13-12PX rev D1: receptacle 12 #20 size contacts, key arrangements A-D, 90 deg, DTM series (customer drawing)
- `examples/valve-ecu/specs/STDC14.yaml` (FTSH-107-01-L-DV-K): Plain 2x7 1.27 mm SMD header (Samtec FTSH-107-01-L-DV-K, the STLINK-V3 STDC14 target connector); generic header, no electrical limits used by ERC. Pinout per ST UM2448 (STLINK-V3SET): 3 T_VCC, 4 SWDIO, 5/7/11 GND, 6 SWCLK, 8 SWO, 12 NRST, 13 T_VCP_RX (target RX), 14 T_VCP_TX (target TX); 1, 2, 9, 10 not used for SWD.
- `examples/valve-ecu/specs/AON6407.yaml` (AON6407): research/AON6407.pdf (sha256 e87c93c653c5...), AOS AON6407 30 V P-channel MOSFET (battery protection)
- `examples/valve-ecu/specs/BUK9Y3R5-40E.yaml` (BUK9Y3R5-40E): research/BUK9Y3R5-40E.pdf (sha256 cfaeaa43ed72...), Nexperia BUK9Y3R5-40E N-channel 40 V logic level MOSFET in LFPAK56 (AEC-Q101)
- `examples/valve-ecu/specs/STM32G474CBT3.yaml` (STM32G474CBT3): https://datasheet.lcsc.com/datasheet/pdf/a99955f86e1b6873dffbae2a2058f698.pdf?productCode=C730123 (sha256 d493fe0ab22e...), ST DS12288 Rev 4 (June 2020; LCSC copy C730123, also cross-checked against Rev 1 May 2019 from Farnell - pin table and limits identical): Table 12 pin definition (LQFP48 column), Table 14 Voltage characteristics (abs max), Table 15 Current characteristics, Table 16 Thermal characteristics, Table 17 General operating conditions, Table 21 Run-mode current (flash single bank), Table 35 Peripheral current consumption, Table 66 ADC characteristics, Table 123 Package thermal characteristics, Section 7 Ordering information
- `specs/parts/TCAN1044V.yaml` (TCAN1044VDRQ1): https://www.ti.com/lit/ds/symlink/tcan1044-q1.pdf (sha256 380f6b3a37fc...), TI SLLSF17D TCAN1044-Q1 family (Aug 2019, rev. Mar 2025): Table 5-1 Pin Functions (D SOIC-8), 6.1 Abs Max, 6.4 Recommended Operating Conditions, 6.5 Thermal Characteristics, 6.6 Supply Characteristics, 6.7 Electrical Characteristics
- `examples/valve-ecu/specs/TPS54360DDAR.yaml` (TPS54360DDAR): research/TPS54360DDAR.pdf (sha256 8c7b9eff00b5...), TI TPS54360 4.5-60 V, 3.5 A step-down converter with Eco-mode, SLVSBB4E (Mar 2014)
- `examples/valve-ecu/specs/AMS1117-3.3.yaml` (AMS1117-3.3): research/AMS1117-3.3.pdf (sha256 189a2651878a...), AMS1117 1 A low dropout voltage regulator
- `examples/valve-ecu/specs/UCC27524AQDRQ1.yaml` (UCC27524AQDRQ1): research/UCC27524AQDRQ1.pdf (sha256 1f30e5b9fc0d...), TI UCC27524A-Q1 dual 5 A low-side gate driver (AEC-Q100): 4 Pin Configuration, 5.1 Abs Max, 5.3 Recommended Operating Conditions, 5.4 Thermal Information
- `specs/parts/X322516MLB4SI.yaml` (X322516MLB4SI): https://datasheet.lcsc.com/datasheet/pdf/a84bd8d530dd46e4b0f6d0ee59d8a89c.pdf?productCode=C13738 (sha256 7bc18549e407...), YXC YSX321SL Crystal Unit datasheet (1 page, LCSC C13738): Specifications table + ESR table; CL from LCSC listing