TEA6323T Philips Semiconductors (Acquired by NXP), TEA6323T Datasheet - Page 6

• Manufacturer Part Number: TEA6323T
• Description: TEA6323T; Sound Fader Control Circuit
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
The last section of the circuit is the volume II block. The
balance and fader functions are performed using the same
control blocks. This is realized by 4 independently
controllable attenuators, one for each output. The control
range of these attenuators is 55 dB in steps of 1 dB with an
additional mute step.
The circuit provides 3 mute modes:
1. Zero crossing mode mute via I
2. Fast mute via MUTE pin.
3. Fast mute via I
The mute function is performed immediately if ZCM is
cleared (ZCM = 0). If the bit is set (ZCM = 1) the mute is
activated after changing the GMU bit. The actual mute
switching is delayed until the next zero crossing of the
audio frequency signal. As the two audio channels (left and
right) are independent, two comparators are built-in to
control independent mute switches.
To avoid a large delay of mute switching when very low
frequencies are processed or the output signal amplitude
is lower than the DC offset voltage a second I
transmission is needed. Both transmissions have the
same data and the second transmission a delay time of
e.g. 100 ms. The first transmission starts the zero cross
circuit, but second transmission moves the mute switch
immediately if the circuit has no zero cross detected.
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
Note
1. Human body model: C = 100 pF; R = 1.5 k ; V
1995 Dec 20
V
V
T
T
V
amb
stg
CC
n
es
Sound fader control circuit
SYMBOL
2 independent zero crossing detectors (ZCM,
see Tables 2 and 9).
see Tables 2 and 9) or volume II block setting
(see Table 4).
supply voltage
voltage at pins 1, 2 and 5 to 40
to pins 3 and 4
operating ambient temperature
storage temperature
electrostatic handling
2
C-bus either by general mute (GMU,
PARAMETER
2
C-bus using
2
C-bus
note 1
2 kV. Charge device model: C = 200 pF; R = 0 ; V
CONDITIONS
6
The mute function can also be controlled externally. If the
mute pin is switched to ground all outputs are muted
immediately (except the outputs volume left and right (OVL
and OVR) and hardware mute). This mute request
overwrites all mute controls via the I
pin is held LOW. The hardware mute position is not stored
in the TEA6323T.
The mute pin can also be used as output. The mute pin
voltage is low when all outputs are in mute position.
For the turn on/off behaviour the following explanation is
generally valid. To avoid AF output caused by the input
signal coming from preceding stages, which produces
output during drop of V
the V
or by grounding the MUTE pin.
For use where is no mute in the application before turn off,
a supply voltage drop of more than 1
mute during the voltage drop.
The power supply should include a V
which provides a discharging time constant. If the input
signal does not disappear after turn off the input will
become audible after certain time. A 4.7 k resistor
discharges the V
current of the IC does not discharge it completely.
The hardware mute function is favourable for use in Radio
Data System (RDS) applications. The zero crossing mute
avoids modulation plops. This feature is an advantage for
mute during changing presets and/or sources (e.g. traffic
announcement during cassette playback).
CC
will drop. This can be achieved by I
CC
0
0
40
65
buffer capacitor, because the internal
MIN.
CC
, the mute has to be set, before
10
V
+85
+150
CC
Preliminary specification
MAX.
2
C-bus for the time the
CC
TEA6323T
V
buffer capacitor,
BE
2
will result in a
C-bus control
V
V
C
C
500 V.
UNIT