TDF8599A NXP Semiconductors, TDF8599A Datasheet - Page 8

• Manufacturer Part Number: TDF8599A
• Description: The TDF8599A is a dual Bridge-Tied Load (BTL) car audio amplifier comprising anNDMOST-NDMOST output stage based on SOI BCDMOS technology
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDF8599A_2
Product data sheet
8.3.2 Spread spectrum mode (Master mode)
The value of the resistor R
In Master mode, Spread spectrum mode and frequency hopping can be enabled. In Slave
mode, phase staggering and phase lock operation can be selected. An external clock can
be used as the master-clock on pin OSCIO of the slave devices. When using an external
clock, it must remain active during the shutdown sequence to ensure that all devices are
switched off and able to enter the off state as described in
In Slave mode, an internal watchdog timer on pin OSCIO is triggered when the TDF8599A
is switched off by pulling down pin EN. If the external clock fails, the watchdog timer forces
the TDF8599A to switch off.
Spread spectrum mode is a technique of modulating the oscillator frequency with a slowly
varying signal to broaden the switching spectrum, thereby reducing the spectral density of
the EMI. Connecting a capacitor (C
Figure
f
Fig 4.
Fig 5.
osc
=
6). When pin SSM is connected to pin AGND, Spread spectrum mode is disabled.
12.45 10
--------------------------- - Hz
Clock frequency as a function of R
Master and slave configuration
R
osc
TDF8599A
9
Master
OSCSET
R
(k )
OSCIO
osc
Rev. 02 — 30 June 2009
50
40
30
20
10
0
300
osc
I
sets the clock frequency based on
2
C-bus controlled dual channel class-D power amplifier
R osc
f
osc
350
SSM
C osc
) to pin SSM enables Spread spectrum mode (see
R
osc
TDF8599A
400
Slave 1
OSCSET
OSCIO
450
f
osc
001aai771
(kHz)
Section 8.2 on page
TDF8599A
Slave 2
500
OSCSET
OSCIO
Equation
001aak075
TDF8599A
© NXP B.V. 2009. All rights reserved.
1:
6.
8 of 54
(1)