TDA8929T NXP Semiconductors, TDA8929T Datasheet - Page 16

• Manufacturer Part Number: TDA8929T
• Manufacturer: NXP Semiconductors

Specifications of TDA8929T

• Lead Free Status / Rohs Status: Compliant

Philips Semiconductors
14 SWITCHING CHARACTERISTICS
V
Notes
1. Frequency set with R
2. For tracking the external oscillator has to switch around SGND + 2.5 V with a minimum voltage of V
14.1
The minimum obtainable pulse width of the PWM output signal of a class-D system, sets the maximum output voltage
swing after the demodulation filter and also the maximum output power. Delays in the power stages are the main cause
for the minimum pulse width being not equal to zero. The TDA8926 and TDA8927 power stages have a minimum pulse
width of t
two during clipping. For the calculation of the maximum output power at clipping the effective minimum pulse width during
clipping is 0.5t
For the practical useable minimum and maximum duty factor
Using the typical values of the TDA8926 and TDA8927 power stages:
3.5% <
2001 Dec 11
t
-------------------------------
Switching frequency
f
f
V
V
f
V
W(min)
osc
osc(r)
track
P
OSC
OSC(trip)
OSC(ext)
Controller class-D audio amplifier
= 25 V; T
SYMBOL
2
Minimum pulse width
W(min)
f
< 96.5%.
osc
amb
W(min)
= 220 ns (typical). Using the TDA8929T controller, the effective minimum pulse is reduced by a factor of
100% <
= 25 C; measured in Fig.10; unless otherwise specified.
oscillator frequency
oscillator frequency range
maximum voltage at pin OSC
trip level at pin OSC for tracking frequency tracking
frequency range for tracking
voltage at pin OSC for tracking
.
OSC
<
PARAMETER
, according to the formula in the functional description.
1
–
t
------------------------------ -
W(min)
2
f
osc
100%
R
R
see Fig.12
note 1
frequency tracking
frequency tracking
note 2
OSC
OSC
CONDITIONS
= 30.0 k
= 27 k ;
16
which determines the maximum output power:
309
210
200
MIN.
317
360
SGND + 2.5
5
TYP.
Preliminary specification
329
600
SGND + 12
600
TDA8929T
MAX.
OSC(ext)
.
kHz
kHz
kHz
V
V
kHz
V
UNIT