AN10436 PHILIPS [NXP Semiconductors], AN10436 Datasheet - Page 12

• Manufacturer Part Number: AN10436
• Description: TDA8932B/33(B) Class-D audio amplifier
• Manufacturer: PHILIPS [NXP Semiconductors]

NXP Semiconductors
AN10436_1
Application note
2.5 Device synchronization
Where:
The oscillator frequency can be set between 250 kHz and 500 kHz.
Example:
The use of a 39 kΩ resistor will result in a oscillator frequency of about 320 kHz.
Remark: A decouple capacitor of 100 nF should be connected across R
reduction.
Remark: Synchronization is recommended when two or more TDA8932B/33(B) devices
are used in the same application (see
Synchronization is recommended to avoid possible audible beat tones from the speakers
when two or more TDA8932B/33(B) devices are used in the same application.
Synchronization can be achieved by connecting all OSCIOs (pin 31) together and
configuring one of the devices as master, while the other TDA8932B/33(B) device is
configured as slave (see
A device is configured as master when a resistor is connected between OSCREF (pin 10)
and V
configured as an oscillator output for synchronization. The OSCREF (pin 10) of the slave
devices should be shortened to V
Remark: In a 2.1 system, the SE device for the L/R channel should be configured as
master.
Remark: The maximum number of slaves driven by one master is 12.
Fig 7. Device synchronization in a 2.1 system
R
osc
SSA
= resistor to set the oscillator frequency.
to set the oscillator frequency. The OSCIO (pin 31) of the master is then
V
SSA
Rev. 01 — 12 December 2007
9
V
TDA8932B/33(B)
SSA
Figure
L/R CHANNEL
39 k
R osc
MASTER
10
OSCREF
7).
SSA
C osc
100 nF
to configure the OSCIO as an input.
Section
31
OSCIO
V
SSA
TDA8932B/33(B) Class-D audio amplifier
2.5).
SUBWOOFER CHANNEL
9
V
TDA8932B/33(B)
SSA
SLAVE
10
OSCREF
010aaa001
31
OSCIO
AN10436
© NXP B.V. 2007. All rights reserved.
osc
for noise
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