
Allegro MicroSystems
Description
The A4405 is an automotive power management IC that uses a high frequency constant on-time 5.45 V pre-regulator to supply two internal 5 V linear regulators and a 3.3 V linear DMOS driver. Designed to supply CAN and microprocessor power supplies in high temperature environments, the A4405 is ideal for under hood applications. Efficient operation is achieved by using a buck pre-regulator to efficiently drop the input voltage
before supplying the linear regulators; this reduces power dissipation and increases overall regulator efficiency.
FEATUREs and Benefits
• AEC Q100 Grade 0 qualified
• Internal buck pre-regulator followed by LDO outputs
• 5.5 to 36 V VIN operating range (50 V maximum);
for start/stop, cold crank, and load dump requirements
• 2.2 MHz constant on-time buck regulator
• Valley current sensing achieves shortest buck on-times
• 50 V absolute maximum input voltage for surges
• 5.5 to 46 V input voltage range
• −40ºC to 150ºC junction temperature range
• Power-on reset (NPOR pin) with adjustable rising delay
• 5 V (V5P pin) internal low dropout tracking linear regulator with both overcurrent foldback and short-to-battery protection
• 5 V (V5 pin) internal low dropout linear regulator with overcurrent foldback protection
• 3.3 V (V33 pin) external linear regulator DMOS driver with a programmable current limit (up to 500 mA) and overcurrent foldback protection
• Logic enable input (ENB pin)
• Ignition enable input (ENBAT pin)
• Ignition status indicator (ENBATS pin)
• Buck pulse-by-pulse overcurrent protection
• Buck LX short circuit protection (latched)
• Missing asynchronous diode protection (latched)
• Switcher (VREG pin), 3.3 V (V33 pin), and charge pump (VCP pin) undervoltage lockout protection (UVLO)
• Thermal shutdown protection (TSD)
APPLICATIONs:
Automotive Control Modules, such as:
• Electronic power steering (EPS)
• Transmission control (TCU)
• Antilock braking (ABS)
• Emissions control