描述 Description

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

特性 Features

Amplifiers
? I2C-bus control
? Can drive a 2?load with a battery voltage of up to 16 V and a 4 ?load 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 2Protection
? 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 conditionsApplications
Boost amplifier and voltage regulator for car radios and CD/MD players