9 Use case No. 5: IGBT module overtemperature detection

As shown in Figure 9-1, a negative temperature coefficient thermistor (NTC) is typically placed inside the IGBT module for the detection of long-term overload conditions. These NTC terminals are routed to the main power board, where the AMC23C14 can be used for overtemperature detection.

Figure 9-2 shows the output waveform for an overtemperature event, where OUT2 pulls high when the input voltage exceeds the threshold values defined by the internal 300-mV reference. The reference pin of the AMC23C14 connects to a 100-μA current source that can bias the NTC.

As the demand to improve system reliability and the adoption of faster switching devices proliferates, the AMC23C14 family of low-latency reinforced isolated comparators solves the critical need for accurate and fast detection in electric motor drives