Cirkit

Source: https://www.cirkit.us/demo/

ISENSE_AMP p3

Goes to the over-current comparator (U6A) on page 4

+24V_IN p1

Protected input rail, after F1 and D1

CAN bus p5

Split termination fitted (R30, R31, C22). Remove R30/R31 when this board isn't at the end of the bus.

Fault logic p4

Either comparator pulls FAULT_N low. The relay closes only when RELAY_EN = 1 and FAULT_N = 1.

Load current sense p3

ISENSE_AMP = 1.25 V + 0.2 V per amp. At 5 A it reads 2.25 V, the over-current trip on page 4.

Buck controller (U1)p1

TPS54360 buck converter, 24 V → 5 V. Bench: 5.02 V at 2 A, 38 mV ripple.

JP1 p5

Jumper 2-pos 2.54 mm

J7 p5

Sensor board connector. The I²C pull-ups (R34, R35) are on this board only.

J6 p5

USB4105-GF-A · USB-C receptacle, USB 2.0

J5 p5

Header 3-pos 2.54 mm

J4 p5

Header 3-pos 2.54 mm

J2 p2

Tag-Connect TC2030 pads (no part fitted)

J3 p4

Terminal block 2-pos 5.08 mm

J1 p1

Terminal block 2-pos 5.08 mm

TP4 p3

5019 · Test point, SMD

TP3 p3

5019 · Test point, SMD

TP2 p1

5019 · Test point, SMD

TP1 p1

5019 · Test point, SMD

SW1 p2

PTS645SM43SMTR92 LFS · Tactile switch

Y1 p2

Crystal 8 MHz, 12 pF load

K1 p4

Coil draws about 17 mA at 24 V. D8 clamps the flyback when Q1 turns off.

L1 p1

Power inductor 22 µH 3.5 A

FB1 p2

BLM18PG601SN1D · Ferrite bead 600 Ω at 100 MHz

F1 p1

Fuse 1.5 A fast-acting

D8 p4

1N4148W-7-F · Switching diode 100 V

D7 p3

BAT54,215 · Schottky diode 30 V

D6 p2

LTST-C191KRKT · LED red

D5 p2

LTST-C191TBKT · LED blue

D4 p1

LTST-C191KGKT · LED green

D3 p1

B560C-13-F · Schottky diode 60 V 5 A

D2 p1

SMBJ28A · TVS diode 28 V

D1 p1

Schottky diode 40 V 5 A

Q1 p4

2N7002LT1G · N-channel MOSFET 60 V 115 mA

U12 p5

USBLC6-2SC6 · USB ESD protection

(USBLC6-2SC6 datasheet.pdf)

U11 p5

TCAN1042HGVDR · CAN FD transceiver

U9 p5

THVD1450DR · RS-485 transceiver, 3.3–5 V

(THVD1450DR datasheet.pdf)

U8 p4

SN74LVC1G08DBVR · Single 2-input AND gate

(SN74LVC1G08DBVR datasheet.pdf)

U7 p4

SN74LVC1G02DBVR · Single 2-input NOR gate

(SN74LVC1G02DBVR datasheet.pdf)

U6 p4

LM393DR · Dual differential comparator

(LM393DR datasheet.pdf)

U6 p4

U6A trips over-current at 2.25 V (5 A), U6B over-voltage at 1.44 V (30 V in). Open-collector, pulled up by R23 / R26.

(LM393DR datasheet.pdf)

U5 p3

REF3312AIDBZR · Voltage reference 1.25 V

(REF3312AIDBZR datasheet.pdf)

U4 p3

OPA2333AIDR · Dual zero-drift op amp

(OPA2333AIDR datasheet.pdf)

U4 p3

OPA2333AIDR · Dual zero-drift op amp

(OPA2333AIDR datasheet.pdf)

U3 p2

Firmware samples ADC_ISENSE at 10 kHz. RELAY_EN stays low until the power-on self-test passes.

(STM32G431CBT6 datasheet.pdf)

U2 p1

TLV1117-33IDCYR · LDO regulator 3.3 V 800 mA

(TLV1117-33IDCYR datasheet.pdf)

U1 p1

24 V → 5 V buck at 600 kHz (R3 = 162k). Output set by R1/R2 against the 0.8 V reference: 0.8 × (1 + 53.6k/10.2k) = 5.00 V.

(TPS54360DDAR datasheet.pdf)

C18 p3

GRM188R71H103KA01D · CAP CER 10 nF 50 V X7R

C20 p3

GRM188R71C105KA12D · CAP CER 1 µF 16 V X7R

C16 p2

GRM188R71C105KA12D · CAP CER 1 µF 16 V X7R

C11 p2

GRM1885C1H120JA01D · CAP CER 12 pF 50 V C0G

C10 p2

GRM1885C1H120JA01D · CAP CER 12 pF 50 V C0G

C9 p1

GRM21BR61A226ME51L · CAP CER 22 µF 10 V X5R

C8 p1

GRM21BR61C106KE15L · CAP CER 10 µF 16 V X5R

C7 p1

GRM1885C1H470JA01D · CAP CER 47 pF 50 V C0G

C22 p5

GRM188R71H472KA01D · CAP CER 4700 pF 50 V X7R

C6 p1

GRM188R71H472KA01D · CAP CER 4700 pF 50 V X7R

C5 p1

GRM32ER71A476KE15L · CAP CER 47 µF 10 V X7R

C4 p1

GRM32ER71A476KE15L · CAP CER 47 µF 10 V X7R

C21 p3