Block and pin description diagrams TDA7391
6/13 DocID1509 Rev 5
Table 2. Pin functional description
Pin# Pin name Description
1, 2 INPUTS
The input stage is a high impedance type also capable of operation in single
ended mode with one input capacitively coupled to the signal GND. The
impedance seen by the inverting and non inverting input pins must be
matched.
3,9 +V
Supply voltage.
4CD
The TDA7391 is equipped with a diagnostic circuitry able to detect the clipping
in the Output Signal (distortion = 10%).
The CD pin (open collector) gives out low level signal during clipping.
5, 7 OUTPUTS
The output stage is a bridge type able to drive loads as low as 3.2. It consists
of two class AB fully complementary PNP/NPN stages fully protected.
A rail to rail output voltage swing is achieved without need of bootstrap
capacitors. No external compensation is necessary.
6 GND Ground.
8 STAND-BY
The device features a standby function which shuts down all the internal bias
supplies when the STAND-BY pin is low. In standby mode the amplifier sinks a
small current (in the range of few A). When the STAND-BY pin is high the IC
becomes fully operational.
10 SYNC
A resistor (R
2
) has to be connect between pin 10 and GND in order to program
the current that flows in the C
3
capacitor (pin 11). The values of C
3
and R
2
determine the time required to bias the amplifier.
11 MUTE
The pin will have a capacitor (C
3
) tied to GND to set the MUTE/STAND-BY
time. An automatic Mute during turn on/off is provided to prevent noisy
transients.
