TDA7491LP13TR STMicroelectronics, TDA7491LP13TR Datasheet - Page 27

• Manufacturer Part Number: TDA7491LP13TR
• Description: IC AMP AUD CLASS D BTL PWRSSO36
• Manufacturer: STMicroelectronics
• Type: Class Dr

Specifications of TDA7491LP13TR

• Output Type: 2-Channel
• Max Output Power X Channels @ Load: 5W x 2 @ 8 Ohm
• Voltage - Supply: 5 V ~ 14 V
• Features: Depop, Differential Inputs, Mute, Short-Circuit and Thermal Protection, Standby
• Mounting Type: Surface Mount
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-11056-2

TDA7491LP
5.5
5.5.1
5.5.2
Internal and external clocks
The clock of the class-D amplifier can be generated internally or can be driven by an
external source.
If two or more class-D amplifiers are used in the same system, it is recommended that all
devices operate at the same clock frequency. This can be implemented by using one
TDA7491LP as master clock, while the other devices are in slave mode, that is, externally
clocked. The clock interconnect is via pin SYNCLK of each device. As explained below,
SYNCLK is an output in master mode and an input in slave mode.
Master mode (internal clock)
Using the internal oscillator, the output switching frequency, f
resistor, R
where R
In master mode, pin SYNCLK is used as a clock output pin, whose frequency is:
For master mode to operate correctly then resistor R
below in
Slave mode (external clock)
In order to accept an external clock input, pin ROSC must be left open, that is, floating. This
forces pin SYNCLK to be internally configured as an input as given in
The output switching frequency of the slave devices is:
Table 8.
Figure 30. Master and slave connection
Master
Slave
f
f
f
SW
SYNCLK
SW
OSC
Table
= 10
= f
OSC
SYNCLK
Mode
How to set up SYNCLK
is in kΩ.
= 2 * f
6
, connected to pin ROSC:
Cosc
100 nF
8.
/ ((16 * R
SW
/ 2
ROSC
OSC
TDA7491LP
Master
Rosc
39 kΩ
+ 182) * 4) kHz
Doc ID 13541 Rev 5
R
Floating (not connected)
OSC
SYNCLK
< 60 kΩ
Output
ROSC
OSC
SYNCLK
must be less than 60 kΩ as given
TDA7491LP
Input
SW
Output
Input
Slave
, is controlled by the
Applications information
Table
ROSC
SYNCLK
8.
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