TDA8950_2
© NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 02 — 11 June 2009
5 of 39
NXP Semiconductors
TDA8950
2
×
150 W class-D power amplifier
7.2 Pin description
8.
Functional description
8.1 General
The TDA8950 is a two-channel audio power amplifier that uses Class D technology.
For each channel, the audio input signal is converted into a digital PWM signal using an
analog input stage and a PWM modulator; see
. To drive the output power
transistors, the digital PWM signal is fed to a control and handshake block and to high-
and low-side driver circuits. This level-shifts the low-power digital PWM signal from a logic
level to a high-power PWM signal switching between the main supply lines.
A 2nd-order low-pass filter converts the PWM signal to an analog audio signal that can be
used to drive a loudspeaker.
Table 3.
Pin description
Symbol
Pin
Description
TDA8950TH
TDA8950J
VSSA
1
18
negative analog supply voltage
SGND
2
19
signal ground
VDDA
3
20
positive analog supply voltage
IN2M
4
21
channel 2 negative audio input
IN2P
5
22
channel 2 positive audio input
MODE
6
23
mode selection input: Standby, Mute or Operating
mode
OSC
7
1
oscillator frequency adjustment or tracking input
IN1P
8
2
channel 1 positive audio input
IN1M
9
3
channel 1 negative audio input
n.c.
10
4
not connected
n.c.
11
5
not connected
n.c.
12
6
not connected
PROT
13
7
decoupling capacitor for protection (OCP)
VDDP1
14
8
channel 1 positive power supply voltage
BOOT1
15
9
channel 1 bootstrap capacitor
OUT1
16
10
channel 1 PWM output
VSSP1
17
11
channel 1 negative power supply voltage
STABI
18
12
decoupling of internal stabilizer for logic supply
n.c.
19
-
not connected
VSSP2
20
13
channel 2 negative power supply voltage
OUT2
21
14
channel 2 PWM output
BOOT2
22
15
channel 2 bootstrap capacitor
VDDP2
23
16
channel 2 positive power supply voltage
VSSD
24
17
negative digital supply voltage
