tea6324t NXP Semiconductors, tea6324t Datasheet - Page 27

• Manufacturer Part Number: tea6324t
• Description: Sound Control Circuit
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Selection of input signals by using the zero crossing
mute mode
The zero cross mute mode provides for a selection of input
sources (A and B) for both left and right channels.
The following example (see Fig.15), shows a typical
selection for the left input source signals IAL and IBL.
The initial selection of these channels produces a
modulation click. The click is determined by the difference
of the signal values at the time of switching.
At t
7 V (p-p) (see Fig.15) and gives a large click. Using the
cross detector no modulation click is audible.
With the selection enabled at t
the zero cross bit (ZCM = 1) and then the mute bit
(GMU = 1) via the I
input A signal from 4 V, until the next zero crossing
occurs and then activates mute.
1997 Mar 13
handbook, full pagewidth
Sound control circuit
1
(1) Input A (IAL).
(2) Output.
(3) Input B (IBL).
the maximum possible difference between signals is
2
V
C-bus. The output signal follows the
4
3
2
1
0
1
2
3
4
1
, the microcontroller sets
Fig.15 Zero cross function; only one channel shown.
t 1
27
After a fixed delay time at t
bits for input switching and mute inactive.
The output signal remains muted until the next signal zero
crossing of input B (IBL) occurs, and then follows that
signal up to 3 V.
With a delay time of 40 ms (t
C
operating at the lowest frequency of 40 Hz determined by
the C
m
= 3.3 nF. This results with the zero cross function
t 2
m
capacitor.
(1)
(2)
(3)
2
, the microcontroller sends the
2
MED436
t
1
Preliminary specification
), the external capacitor
t
TEA6324T