TDA8950 datasheet(7/39 Pages) NXP

7 / 39 page

TDA8950_1

Preliminary data sheet

Rev. 01 — 9 September 2008

7 of 39

NXP Semiconductors

TDA8950

× 150 W class-D power ampliﬁer

In order to fully charge the coupling capacitors at the inputs, the ampliﬁer will remain

automatically in the Mute mode before switching to the Operating mode. A complete

overview of the start-up timing is given in Figure 5.

(1) First 1

⁄

4 pulse down.

Upper diagram: When switching from standby to mute, there is a delay of approximately 100 ms

before the output starts switching. The audio signal is available after VMODE has been set to

operating, but not earlier than 150 ms after switching to mute. For pop noise-free start-up it is

recommended that the time constant applied to pin MODE is at least 350 ms for the transition

between mute and operating.

Lower diagram: When switching directly from standby to operating, there is a ﬁrst delay of 100 ms

before the outputs starts switching. The audio signal is available after a second delay of 50 ms. For

pop noise-free start-up it is recommended that the time constant applied to pin MODE is at least

500 ms for the transition between standby and operating.

Fig 5.

Timing on mode selection input

2.2 V

< VMODE < 3 V

audio output

operating

standby

mute

50 %

duty cycle

> 4.2 V

0 V (SGND)

time

001aah657

VMODE

100 ms

50 ms

modulated PWM

> 350 ms