JAJSP50A May 2023 – September 2023 AMC131M03-Q1
PRODUCTION DATA
This section describes the use of the AMC131M03-Q1 in a typical battery management system (BMS). The device serves as a voltage monitor for various subsystems that are connected to the battery pack using contactors. As illustrated in Figure 9-4, the battery pack is typically supervised by a battery pack monitor, which measures battery current using a low-side current shunt sensor, battery-pack voltage using a high-voltage resistor divider, and shunt temperature using a linear negative temperature coefficient (NTC) thermistor. The battery pack terminals (PACK+ and PACK– in Figure 9-4) are connected to the high voltage load (for example, the traction inverter), that is the LINK+ and LINK– nodes, through contactors S1 (A and B) and S2. These contactors are critical to disconnect the battery from the load in case a system failure is detected. In Figure 9-4, the AMC131M03-Q1 supervises the CHARGE+ and CHARGE– voltages of the DC fast charger, which is connected to the LINK+ and LINK– nodes through contactors S3 and S4.
Monitoring the CHARGE+ and CHARGE– voltages with the AMC131M03-Q1 serves several objectives:
An isolated measurement is required to protect the digital control circuitry in the low voltage domain from the high voltage levels at the CHARGE+ and CHARGE– nodes.
Other subsystems, such as a heater, that are also connected to the LINK+ and LINK– nodes can be monitored with additional AMC131M03-Q1 devices similar to Figure 9-4.