Description
The A4407 is an automotive power management IC that uses a 2.2 MHz constant on-time (COT) buck pre-regulator to supply a 5 V linear regulator, a 5 V tracking/protected linear regulator, a 3.3 V linear FET controller/driver, and a 1.2 V/1.5 V/1.8 V linear FET controller/driver. The A4407 provides a pin to set the master reference for the 5 V tracking regulator to either the 3.3 V or the 5 V output. The on-time of the buck is internally adjusted as a function of VINto maintain the 2.2 MHz switching frequency. Efficient operation is achieved by using the buck pre-regulator to drop the input voltage before supplying the linear regulators. Designed to supply CAN and microprocessor power supplies in high temperature environments, the A4407 is ideal for under hood applications.

FEATUREs and Benefits
• AEC Q100 Grade 0 qualified
• Internal buck pre-regulator followed by LDO outputs
• 5.5 to 36 V V
IN operating range (50 V maximum);
for start/stop, cold crank, and load dump requirements
• Constant on-time (COT) buck pre-regulator
• Valley current sensing achieves shortest buck on-times
• 2.2 MHz (VIN- adjusted) switching frequency
• 5 V internal low-dropout tracking linear regulator with
foldback short circuit and short-to-battery protections
• 5 V internal low-dropout linear regulator with foldback
short circuit protection
• 3.3 V external FET controller/driver with programmable
current limit and foldback short circuit protection
• 1.2 V/1.5 V/1.8 V external FET controller/driver with
programmable current limit and foldback protection
• Power-on reset (NPOR) with adjustable rising delay
• Logic enable input (ENB) for microprocessor control
• Ignition enable input (ENBAT) for remote startup
• Ignition status indicator (ENBATS) output
• Buck pulse-by-pulse overcurrent protection
• Buck LX short circuit protection (latched)
• Missing asynchronous diode protection (latched)
• UVLO for VIN, charge pump, and the internal rail
• Thermal shutdown protection
• −40ºC to 150ºC junction temperature range