JBL SP-150, Service Manual, Page: 33 / 51

TDA8920C_1 © NXP B.V. 2008. All rights reserved.
Preliminary data sheet Rev. 01 — 29 September 2008 5 of 40
NXP Semiconductors
TDA8920C
2
×
110 W class-D power amplifier
7.2 Pin description
8. Functional description
8.1 General
The TDA8920C is a two-channel audio power amplifier using class-D technology.
The audio input signal is converted into a digital pulse-width modulated signal using an
analog input stage and PWM modulator; see
Figure 1 . To enable the output power
transistors to be driven, the digital PWM signal is applied to a control and handshake
block and driver circuits for both the high side and low side. 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 across the
loudspeakers.
Table 3. Pin description
Symbol Pin Description
TDA8920CTH TDA8920CJ
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
JBL 150P / 230V Service Manual
Page 32 of 50