ST STEVAL-BMS1T User Manual

Getting started with the STEVAL-BMS1T, SPI to isolated SPI dongle based on the
Introduction
The STEVAL-BMS1T board allows converting SPI signals into ISOSPI signals, reducing the number of necessary wires from 4
to 2, and ensuring an isolated differential communication that is highly immune to noise.
An ISOSPI signal can travel for several meters, maintaining a high ratio between signal and noise.
The ISOSPI protocol features differential communication to ensure higher noise immunity and robustness for long distance
communication.
The STEVAL-BMS1T board is based on the
transceiver, which can transfer communication data incoming from a classical 4-wire based SPI interface to a 2-wire isolated
interface (and vice versa).
The L99BM1T hosted on the
any protocol of 8-to-64-bit SPI frames. The SPI peripheral can work up to 10 MHz when configured as a slave. The SPI clock
frequency can be programmed (250 kHz, 1 MHz, 4 MHz, or 8 MHz) when the device is configured as a master.
The transceiver is natively compatible with the L99BM114 IC isolated SPI port, allowing its usage in battery management
system (BMS) applications. The basic BMS analog front-end node board is the STEVAL-BMS114. From the microcontroller side,
the STEVAL-BMS1T board can be connected via SPI with STM32 microcontroller families.
UM3422 - Rev 1 - January 2025
For further information, contact your local STMicroelectronics sales office.
Figure 1. SPI to ISOSPI conversion block diagram
L99BM1T integrated circuit, a general-purpose SPI to isolated SPI bi-directional
STEVAL-BMS1T can be configured either as a slave or as a master of the SPI bus and supports
UM3422
User manual
L99BM1T transceiver
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