```mermaid
flowchart LR
subgraph Power Tree
VIN["28V Input"] --> BUCK12["12V Buck Regulator"] --> Rail12["12V Rail"]
VIN --> BUCK5["5V Buck Regulator"] --> Rail5["5V Rail"]
VIN --> LDO3V3["3.3V Regulator"] --> Rail3V3["3.3V Rail"]
BUCK12 --> IND12["Inductor & EMI Filter"]
BUCK5 --> IND5["Inductor & EMI Filter"]
LDO3V3 --> IND3["Inductor & EMI Filter"]
end
subgraph Microcontroller & CAN
MCU["Microcontroller w/ CAN"] -->|"3.3V, 5V, 12V"| Rail3V3 & Rail5 & Rail12
MCU -->|"CAN_TX/CAN_RX"| ISO_CAN["Isolated CAN Transceiver"]
ISO_CAN --> CHOKE["Common-Mode Choke"] --> TERM["Selectable 120Ω Termination"] --> ESD["ESD Protection"] --> CAN_CONN["J1939 CAN Connector"]
end
subgraph BMS System
BMS_AFE["7S Li-ion BMS AFE"] --> CELL_TAPS["Cell Voltage Taps"]
BMS_AFE --> SHUNT["Current Sense (Shunt/Hall)"]
BMS_AFE --> TH["NTC Thermistors"]
BMS_AFE --> CONTACTOR["Contactor Driver"]
BMS_AFE --> PRECHARGE["Precharge Path"]
VIN --> PROT["TVS, Fuse, Reverse-Polarity FET"] --> BMS_AFE
BMS_AFE --> PACK_CONN["Pack/Charger Connector"]
end
% Interconnections
Rail3V3 & Rail5 & Rail12 --> MCU
Rail3V3 --> ISO_CAN & BMS_AFE
ISO_CAN --> MCU
MCU --> BMS_AFE
```