NXP Semiconductors
UM10340_5
TFA9879 demonstration PCB
© NXP B.V. 2011. All rights reserved.
User manual
Rev. 05 — 30 aug. 2011
5 of 20
2. Setup demonstration PCB
2.1 Hardware setup
Figure 2 is showing the hardware setup of the TFA9879 mono demonstration PCB with
screw terminals for connecting the power supply (X3) and the speaker cables (X7).
The speaker can be driven by the Class-D amplifier with:
•
A digital audio signal via the headers X4 (I2S input 1) or X5 (I2S input 2);
•
An analog stereo audio signal via the RCA Jacks X14 and X11 (I2S input 2).
Remark: Default the ADC is connected to the I2S input 2 of the TFA9879 via R35, R36
and R37 (10R, see schematic in paragraph 4). These 10R resistors must be removed
from the PCB when driving I2S via X5.
The USM interface (USB to I2C converter) including the 4-wire flat cable, which are
provided with the board, should be connected between demonstration PCB (connector
X9) and USM interface. The USB port should be connected to the PC.
Important remark:
First install the GUI software (see paragraph 2.2.1), which includes the
USB driver, before connecting the USM interface to the PC.
+ OUT - Supply I2C
input
Right Left
Analog Class-D input
S3
X7 X3
X14 X11
S2
S4
S1
X4 X5
X9
Digital
Class-D input
I2S input 1
I2S input 2
S5
3
Figure 2: Setup demonstration PCB
Figure 3: USM interface
Table 1. Input/output connector assignment
REF TYPE
Pin
Label
Description
X3
Terminal block, screw
1
GND
Ground
2
V
P
Positive supply input (2.5V…5.5V)
X4
Header, double row
1, 2, 9, 10
Not connected
3
SDI1
Data input 1
