NXP Semiconductors
UM10340_5
TFA9879 demonstration PCB
© NXP B.V. 2011. All rights reserved.
User manual
Rev. 05 — 30 aug. 2011
3 of 20
1. Introduction
This User Manual describes the TFA9879 digital input mono Class-D amplifier
demonstration PCB based on NXP Semiconductors’ TFA9879HN device. Extension “HN”
is referring to the HVQFN24 package dedicated for reflow soldering.
The TFA9879 demonstration PCB is designed in such a way that it is easy to operate the
TFA9879 device for demonstration purposes and for validation. Therefore the
demonstration PCB facilitates the following circuitry (see Figure 1):
•
TFA9879 Class-D amplifier requires only three external components that are
stuffed at a translation PCB.
•
Analog to digital converter (ADC + clock generator, I2S format, fs = 48kHz) to
drive the speaker via the Class-D amplifier with analog signals.
•
3.3V buck boost converter (DCDC) for the ADC and I2C pull-up voltage.
•
1.8V linear regulator for the digital core of the TFA9879.
•
External 15kV ESD protection at amplifier output.
Figure 1: Block diagram demonstration PCB
Demonstration PCB
Speaker
TFA9879
OUTA
Class-D
Class-D
Volume control
5-band parametric EQ
DRC
Bass-treble control
High-pass filter
Power limiter
PWM
modulator
PLL
I2C
control
interface
Interface
I2S input 1
I2S input 2
I2C control input
Protections
OCP
OTP
Mono speaker driver
Digital processor
Digital
audio
receiver
MUX
Input
protections
OFP
UFP
IBP
VDDP
VDDD
Supply 2.5V...5.5V
Feedback
loop
Feedback
loop
OUTB
C
STABA
STABA
1.8V
Address select
A/D converter
3.3V
Analog input
Class-D amplifier
1.8V linear
regulator
3.3V buck boost
converter
12.29 MHz
Left
ADC
SYSCLK
Right
LRCK1
SCK1
SDI1
3.3V
V
P
SDA
S1
1.8V
1.8V
LRCK2
SCK2
SDI2
S3
S4
S2
Shutdown
DCDC
Shutdown
LDO
Shutdown
ADC
GNDP
GNDD
GND
S5
SCL
ADSEL1
ADSEL2
