SBASAJ8A June 2022 – August 2022 AMC22C12
PRODUCTION DATA
Fast overcurrent detection is a common requirement in DC/DC converter and motor-control applications, and can be implemented with an AMC22C12 isolated window comparator as shown in Figure 8-1.
The load current flowing through an external shunt resistor RSHUNT produces a voltage drop that is sensed by the AMC1200 for control purposes. The same voltage is monitored by the AMC22C12 that is connected in parallel to the current-sensing amplifier and provides a fast sensing path for positive and negative fault-current detection. The overcurrent detection threshold is set by the external resistor R1 and the overcurrent event is signaled on the open-drain output OUT.
As depicted in Figure 8-1, the integrated low-dropout (LDO) regulator on the high-side allows direct connection of the VDD1 input to a commonly used floating gate-driver supply. Alternatively, the AMC22C12 can share a regulated supply with the AMC1200. In that case, the VDD1 pin of the AMC22C12 connects directly to the VDD1 pin of the AMC1200 and R4 is not needed. The fast response time and high common-mode transient immunity (CMTI) of the AMC22C12 ensure reliable and accurate operation even in high-noise environments.