TDF8599 datasheet(22/52 Pages) NXP

22 / 52 page

TDF8599_1

Product data sheet

Rev. 01 — 13 November 2008

22 of 52

NXP Semiconductors

TDF8599

Class-D power ampliﬁer with load diagnostics

In Parallel mode, disabling clip detection on both channels requires both bits to be set to

bit IB1[D5] = 1 and bit IB2[D5] = 1.

8.6.3 Start-up and shutdown sequence

To prevent the switch on or switch off ‘pop noise’, a capacitor (CSVR) connected to pin SVR

is used to smooth start-up and shutdown. During start-up and shutdown, the output

voltage tracks the voltage on pin SVR. Increasing CSVR results in a longer start-up and

shutdown time. Enhanced pop performance is achieved by muting the ampliﬁer until the

SVR voltage reaches its ﬁnal value and the outputs start switching. The capacitor on the

pin SEL_MUTE (CON) determines the unmute and mute timing. The voltage on pin

SEL_MUTE determines the ampliﬁer gain. Increasing CON increases the unmute and

mute times. In addition, a larger CON value increases the DC load detection cycle.

When the ampliﬁer is switched off with an I2C-bus command or by pulling pin EN low, the

ampliﬁer is ﬁrst muted and then capacitor (CSVR) is discharged.

In Slave mode, the device enters the off state immediately after capacitor (CSVR) is

discharged. In Master mode, the clock is kept active by an additional delay (td(2)) of

approximately 50 ms to allow slave devices to enter off state.

When an external clock is connected to pin OSCIO (in Slave mode), the clock remains

active during the shutdown sequence (td(1)) to ensure that the slaved TDF8599 devices

are able to enter the off state.

(1) Shutdown hold delay

(2) Master mode shutdown delay

(3) Shutdown delay

Fig 21. Start-up and shutdown timing in I2C-bus mode with DC load detection

001aai790

VDDA

DIAG

ACGND

IB1[D0] and

IB2[D0]=0

SEL_MUTE

SVR

OUT

td(2)

td(1)

mute on delay

td(stb-mute)

twake

tdet(DCload)

td(3)

TDF8599 Datasheet(PDF) 22 Page - NXP Semiconductors

TDF8599 Datasheet(HTML) 22 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

Datasheet Download

Link URL