The A4412 is a power management IC that uses a buck or buck/boost pre-regulator to efficiently convert automotive battery voltages into a tightly regulated intermediate voltage complete with control, diagnostics and protections. The output of the preregulator supplies a 5 V / 100 mA protected linear regulator, a 3.3 V / 90 mA linear regulator, a 5 V / 200 mA linear regulator, a 5 V / 55 mA linear regulator, a 5 V / 30 mA linear regulator and an adjustable 400 mA synchronous buck regulator. Designed to supply CAN transceiver, sensor, and microprocessor power supplies in high-temperature environments, the A4412 is ideal for under-hood applications.
Enable inputs to the A4412 include a logic level (ENB) and a high-voltage (ENBAT). The A4412 also provides flexibility with disable function of the individual 5 V rails through a serial peripheral interface (SPI).
Diagnostic outputs from the A4412 include a power-on-reset output (NPOR), an ENBAT status output, and a fault flag output to alert the microprocessor that a fault has occurred. The microprocessor can read fault status through SPI. Dual bandgaps, one for regulation and one for fault checking, improve safety coverage and fault detection of the A4412.
The A4412 contains a Window Watchdog timer with a detect period of 2 ms. The watchdog timer is activated once it receives valid 2 ms pulses from the processor. The watchdog can be put into flash mode or be reset via secure SPI commands.
Protection features include undervoltage and overvoltage on all output rails. In case of a shorted output, all linear regulators feature foldback overcurrent protection. In addition, the V5P output is protected from a short-to-battery event. Both switching regulators include pulse-by-pulse current limit, hiccup mode short-circuit protection, LX short-circuit protection, missing asynchronous diode protection (VREG only) and thermal shutdown.
The A4412 is supplied in a low-profile (1.2 mm maximum height) 38-lead eTSSOP package (suffix “LV”) with exposed power pad.