GENERAL DESCRIPTION
The TDA3609JR 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 a foldback current protection (regulator 1 and regulator 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 protections, operated by an enable input
• Reset and hold outputs that can be used to interface by the microcontroller. The reset-signal can be used to call up the microcontroller and the hold output indicates regulator 1 voltage available and within range.

• A supply pin which can withstand load dump pulses and negative supply voltages.
• Regulator 2 that will be switched on at a back-up voltage greater than 6.5 V and off when the output voltage of regulator 2 drops below 1.9 V.
• A provision for 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.