E-TDA7396 Datasheet, PDF (4/11 Pages) STMicroelectronics – 45W/2W BRIDGE CAR RADIO AMPLIFIER WITH DIAGNOSTIC FACILITY

TDA7396
FUNCTIONAL DESCRIPTION
Pin
Function
Description
The input stage is a high impedance differential type also capable of operation in single
1, 2
INPUTS
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.
The TDA7396 is equipped with a diagnostics circuitry able to detect the following events:
- Clipping in the Output Signal
- Thermal Shutdown
- Open Load (before turn-on)
4
CD - DIA
- Shorted Output: to GND, to Vs, across the load (after turn-on)
The CD-DIA(open collector) pin gives out the diagnostics signal (low during clipping or
output fault condition).
The device does not work as long as the faulty condition holds; the normal operation is
automatically restored after the fault removal.
The output stage is a bridge type able to drive loads as high as 2Ω.
5, 7
OUTPUTS
It consists of two class AB fully complementary PNP/NPN stages fully protected.
A rail to rail output voltage swing is achieved with no need of bootstrap capacitors.
No external compensation is necessary.
The device features a ST-BY function which shuts down all the internal bias supplies
8
STAND-BY
when the ST-BY input is low.
In ST-BY mode the amplifier sinks a small current (in the range of few µA).
When the ST-BY pin is high the IC becomes fully operational.
A resistor (R_S) has to be connect between pin 10 and GND in order to program the
10
SYNC
current that flows into C_M capacitor (pin 11). The values of C_M and R_S determine the time
required to bias the amplifier.
a) The pin will have a capacitor (C_M) tied to GND to set the MUTE/STAND-BY time. An
automatic Mute during turn on/off is provided to prevent noisy transients
11
MUTE
b) If a independent Mute function is needed, an external transistor circuit (see fig. 4) may
be connected to this pin; 1% precision resistors have to be used for R_EXT / R_S in to order
to reach the fixed limits 0.63 ≤ R_EXT / R_S ≤ 0.69
Figure 3: Application Circuit with External Mute Control
0.22µF
IN+
0.22µF
IN-
STANDBY
TO µC or VS
REXT
TO µC
23
100nF
9
OUT+
7
1
OUT-
TDA7396 5
8
CD-DIA
11
10
64
GND
CM
RS
+VS
1000µF
Vref
10KΩ
TO µC
D93AU007
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