# Internal Circuits ## Power, CAN Block Diagram The Helot modules contain transient voltage suppression and reverse polarity protection. An internal fuse is included between the +VSUPPLY bus and the module power circuitry to reduce the risk of a faulty module taking down the entire bus and other connected devices.

## Isolation Block Diagram The modules are designed to provide 1kV of isolation between the Power, CAN Interface (J2/J3) and the Battery Cell Interface (J1). This isolation is implemented with two digital isolators spanning the GND and IGND references, between the MCU and Battery ASIC.

## Balancing Front-end Circuit Diagram All cell tap interfaces are fused ([Bel Fuse C2Q-250](https://www.belfuse.com/product/part-details?partn=C2Q-250)) to mitigate the risk of cell damage in the event of an internal module failure or short circuit. 47 Ohm, automotive grade pulse withstanding resistors are used for dissipative shunting of cell currents.

BMS100 - Balancing Front-end Circuit Diagram

## NTC Input Circuit Diagram The internal Battery ASIC provides a switched +2.5V reference bias, via a 10K pull-up for each of the two (2) external NTC temperature sensors. {% hint style="warning" %} Never injected voltage into the VTEMP pins, as it may damage the internal circuitry. {% endhint %}