General description
1.1 Amplifiers
The TDF8553 has a complementary quad audio power amplifier that uses BCDMOS technology. It contains four amplifiers configured in Bridge Tied Load (BTL) to drive speakers for front and rear left and right channels. The I2C-bus allows diagnostic information of each amplifier and its speaker to be read separately. Both front and both rear channel amplifiers can be configured independently in line driver mode with a gain of 20 dB (differential output) or amplifier mode with a gain of 26 dB (BTL output).

1.2 Voltage regulators
The TDF8553 has a multiple output voltage regulator with two power switches.
The voltage regulator contains the following:
• Four switchable regulators and two standby regulators
• Two power switches with loss-of-ground protection and surge protection
• Second supply pin to reduce dissipation by means of an external DC-to-DC converter

FEATUREs
Amplifiers
  I2C-bus control
  Can drive a 2Ωload with a battery voltage of up to 16 V and a 4 Ωload with a
  battery voltage of up to 18 V
  DC load detection, open, short and present
  AC load (tweeter) detection
  Programmable clip detect; 1 % or 4 %
  Programmable thermal protection pre-warning
  Independent short-circuit protection per channel
  Selectable line driver (20 dB) and amplifier mode (26 dB)
  Loss-of-ground and open VPsafe
  All outputs protected from short-circuit to ground, to VPor across the load
  All pins protected from short-circuit to ground
  Soft thermal-clipping to prevent audio holes
  Low battery detection

Voltage regulators
  I2C-bus control
  Good stability for any regulator with almost any output capacitor value
  Six voltage regulators (microcontroller, display, audio processor, tuner, bus, mechanical digital and drive)
  Selectable output voltages for regulators 1, 4 and 5
  Low dropout voltage PNP output stages
  High supply voltage ripple rejection
  Low noise for all regulators
  Two power switches (antenna switch and amplifier switch)
  Standby regulators 2 and 6 (microcontroller and bus supply) operational during load dump and thermal shut-down
Low standby quiescent current (only regulators 2 and 6 operational)
Second supply pin for connecting optional external DC-to-DC converter to reduce internal dissipation
Backup functionality for regulator 2

Protection
  If connection to the battery voltage is reversed, all regulator voltages will be zero
  Able to withstand output voltages up to 18 V (supply line may be short-circuited)
  Thermal protection to avoid thermal breakdown
  Load-dump protection
  Regulator outputs protected from DC short-circuit to ground or to supply voltage
  All regulators protected by foldback current limiting
  Power switches protected from loss-of-ground and surge conditions

APPLICATIONs
Boost amplifier and voltage regulator for car radios and CD/MD players