TDA8922B NXP Semiconductors, TDA8922B Datasheet - Page 5

• Manufacturer Part Number: TDA8922B
• Description: The TDA8922B is a high efficiency class-D audio power amplifier with very lowdissipation
• Manufacturer: NXP Semiconductors

Philips Semiconductors
8. Functional description
9397 750 13357
Preliminary data sheet
8.1 General
Table 3:
The TDA8922B is a two channel audio power amplifier using class-D technology.
The audio input signal is converted into a digital Pulse Width Modulated (PWM) signal via
an analog input stage and PWM modulator. To enable the output power transistors to be
driven, this digital PWM signal is applied to a control and handshake block and driver
circuits for both the high side and low side. In this way a level shift is performed from the
low power digital PWM signal (at logic levels) to a high power PWM signal which switches
between the main supply lines.
A 2nd-order low-pass filter converts the PWM signal to an analog audio signal across the
loudspeakers.
The TDA8922B one-chip class-D amplifier contains high power D-MOS switches, drivers,
timing and handshaking between the power switches and some control logic. For
protection a temperature sensor and a maximum current detector are built-in.
The two audio channels of the TDA8922B contain two PWMs, two analog feedback loops
and two differential input stages. It also contains circuits common to both channels such
as the oscillator, all reference sources, the mode functionality and a digital timing
manager.
The TDA8922B contains two independent amplifier channels with high output power, high
efficiency, low distortion and a low quiescent current. The amplifier channels can be
connected in the following configurations:
Symbol
SGND1
V
PROT
V
BOOT1
OUT1
V
STABI
n.c.
V
OUT2
BOOT2
V
V
•
•
SSA1
DDP1
SSP1
SSP2
DDP2
SSD
Mono Bridge-Tied Load (BTL) amplifier
Stereo Single-Ended (SE) amplifiers.
Pin description
Pin
TDA8922BTH TDA8922BJ
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Rev. 01 — 1 October 2004
…continued
5
6
7
8
9
10
11
12
-
13
14
15
16
17
Description
signal ground for channel 1
negative analog supply voltage for channel 1
decoupling capacitor for protection (OCP)
positive power supply voltage for channel 1
bootstrap capacitor for channel 1
PWM output from channel 1
negative power supply voltage for channel 1
decoupling of internal stabilizer for logic supply
not connected
negative power supply voltage for channel 2
PWM output from channel 2
bootstrap capacitor for channel 2
positive power supply voltage for channel 2
negative digital supply voltage
2
50 W class-D power amplifier
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
TDA8922B
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