TDF8553J NXP Semiconductors, TDF8553J Datasheet - Page 12

• Manufacturer Part Number: TDF8553J
• Description: I2C-bus controlled 4 X 50 Watt power amplifier and multiple voltage regulator
• Manufacturer: NXP Semiconductors

www.DataSheet4U.com
NXP Semiconductors
TDF8553J_1
Objective data sheet
8.6.1 Standby regulator outputs
8.6.2 Backup capacitor
8.6 Voltage regulators
The voltage regulator section contains:
The TDF8553 uses low dropout voltage regulators for use in low voltage applications.
All of the voltage regulators except for the standby regulators can be controlled via the
I
capable of delivering unregulated continuous current, and has several fail-safe protection
modes. It conforms to peak transient tests and protects against continuous high voltage
(24 V), short-circuits and thermal stress. Standby regulators 2 and 6 will try to maintain
output for as long as possible even if a thermal shut-down or any other fault condition
occurs. During overvoltage stress conditions, all outputs except regulators 2 and 6 will
switch off and the device will be able to supply a minimum current for an indefinite amount
of time sufficient for powering the memory of a microcontroller and bus controller
functionality. Provision is made for an external reserve supply capacitor to be connected
to pin BUCAP which can store enough energy to allow regulator 2 to supply a
microcontroller for a period long enough for it to prepare for a loss-of-voltage.
Standby outputs (regulators 2 and 6) are used for the microcontroller and bus controller
supply. These regulators will not shut down with the switched regulators and cannot be
controlled by the I
transients or by high temperature protection.
The backup capacitor (C
the battery supply voltage (V
2
Fig 4.
•
•
•
•
C-bus. The voltage regulator section of this device has two power switches which are
Four switchable regulators and two standby regulators
Two power switches with loss-of-ground and surge protection
Second supply pin to reduce dissipation by means of an external DC-to-DC converter
Backup functionality for regulator 2
8.4
(V)
14
V
7
Amplifier output during supply voltage drop
V
SVR voltage
P
2
C-bus. The standby regulators will not shut down during load dump
Rev. 01 — 3 December 2008
backup
4
P
) is used as a backup supply for the regulator 2 output when
) cannot support the regulator 2 voltage.
vehicle engine start
50 Watt power amplifier and multiple voltage regulator
headroom voltage
TDF8553J
© NXP B.V. 2008. All rights reserved.
amplifier
DC output voltage
t (s)
001aai692
12 of 47