GENERAL DESCRIPTION
The TDA3618AJR is a multiple output voltage regulator with a power switch and ignition buffers, intended for use in car radios with or without a microcontroller. It contains:
• Two fixed voltage regulators with foldback current protection (regulators 1 and 3) and one fixed voltage regulator (regulator 2) intended to supply a microcontroller, that also operates during load dump and thermal shutdown
• A power switch with protection, operated by an enable input
• Reset and hold outputs that can be used to interface with the microcontroller; the reset signal can be used to wake up the microcontroller
• A supply pin that can withstand load dump pulses and negative supply voltages
• Regulator 2, which is switched on at a backup voltage greater than 6.5 V and off when the output voltage of regulator 2 drops below 1.9 V
• A provision for the use of a reserve supply capacitor that will hold enough energy for regulator 2 (5 V continuous) to allow a microcontroller to prepare for loss of voltage
• An inverted ignition 1 input with open collector output stage
• An ignition 2 input Schmitt trigger with push-pull output stage.

FEATURES
General
• Extremely low noise behaviour and good stability with very small output capacitors
• Two VP-state controlled regulators and a power switch
• Regulator 2, reset and ignition buffer operate during load dump and thermal shutdown
• Separate control pins for switching regulator 1, regulator 3 and the power switch
• Supply voltage range from −18 to +50 V
• Low reverse current of regulator 2
• Low quiescent current when regulator 1, regulator 3 and the power switch are switched off
• Hold output for low VP
• Hold output for regulators 1 and 3
• Hold output for foldback mode switch
• Hold output for load dump and temperature protection
• Reset (push-pull) and hold (open collector) outputs
• Adjustable reset delay time
• High ripple rejection
• Backup capacitor for regulator 2
• Two independent ignition buffers, one inverted and with open collector output.

Protection
• Reverse polarity safe, down to −18 V
• Able to withstand voltages up to 18 V at the outputs
   (supply line may be short-circuited)
• ESD protected on all pins
• Thermal protections with hysteresis
• Load dump protection
• Foldback current limit protection for regulators 1, 2 and 3
• Delayed second current limit protection for the power switch at short-circuit
• The regulator outputs and the power switch are DC short-circuit safe to ground and VP.