A81407: Multi-Output Regulator with Buck or Buck-Boost Pre-Regulator, 4× LDO Outputs, Watchdog, 4× Gate Drivers, and SPI

The A81407 is ideal for both Automotive and Industrial applications, where high temperature operation, a high level of integration, and robust solutions are required.

The IC integrates a buck or buck/boost pre-regulator, four LDOs, and four floating gate drivers. The pre-regulator uses a buck or buck/boost topology to efficiently convert input voltages into a tightly regulated intermediate voltage. Frequency dithering and slew control help reduce EMI. The output of the pre-regulator supplies a 3.3 V / 375 mA linear regulator, a 5 V / 150 mA linear regulator, and two 5 V / 120 mA linear regulators. All of the outputs are protected against short circuits, and two are further protected from short-to-supply voltage in case they are used remotely.

The independent floating gate drivers can be used for switched loads such as motor phases, solid state relays, and solenoid valves. They have the capability of controlling N-channel MOSFETs through SPI. An integrated charge pump allows the driver outputs to maintain the power MOSFETs in the on state over the full supply range with high phase-voltage slew rates.

Diagnostic outputs from the A81407 include a Watchdog Fault (WD_Fn), power-on reset (NPOR), and a fault flag (FFn) to alert the microprocessor that a fault has occurred. The microprocessor can read fault registers through SPI and operational status via an analog multiplexor.

• A2-SIL™ pending—device features for safety-critical systems
• Automotive AEC-Q100 qualified
• Wide input voltage range, 3.8 to 36 VIN operating range,40 VIN maximum
• 2.2 MHz buck or buck/boost pre-regulator (VREG: 5.35 V) with low EMI frequency dithering
• Four internal linear regulators with foldback short-circuit protection
• VUC: selectable output (3.3 V / 5.0 V) regulator for microcontroller
• V5A: 5 V general purpose LDO regulator
• V5P1 and V5P2: two LDO regulators with short-to-battery protection for remote sensors
• OV and UV protection for all output rails provide the ability to monitor health of outputs
• Pulse Width Watchdog (PWWD), Window Watchdog (WWD), and Q&A Watchdog (QAWD)
• Floating gate drivers (with charge pumps) for external switched load control
• Analog multiplexor (AMUX) reports operational values of multiple important parameters
• Safety signal (POE) can disable a separate function (e.g., Motor Driver) due to a Watchdog Failure