ST TDA7396 User Manual

®

45W/2Ω BRIDGE CAR RADIO AMPLIFIER

HIGH POWER CAPABIL ITY:

- 65W/2Ω MAX

- 60W/2Ω EIAJ

- 45W/2Ω @ V
DIFFERENTIAL INPUTS (EITHER SINGLE

ENDED OR DI FFERENTIAL INPU T SIGNALS
ARE ACC EPTED)

MINIMUM EXTERNAL COMPONENT COUNT:

- NO BOOTSTRAP CAPACITORS

- NO BOUCHEROT CELLS

- INTERNALLY FIXED GAIN (26dB)

- NO SVR CAPACITOR
ST.-BY FUNCTION (CMOS COMPA TIBLE)
AUTOMATIC MUTE DURING TURN-ON /OFF
AUTOMU T E AT MINIM UM SUPPLY

VOLTAGE DETECTION
SYNCHRONIZING PIN FOR SIMULTANEOUS

TURN-ON IN MULTI-DEVICE APPLICATIONS
NO AUDIBLE POP DURING MUTE AND ST-

BY OPERATIONS

Diagnostic Facilities:

CLIPPING DETECTOR

Figure 1: Test And Application Circuit

S

= 14.4V, f = 1KHz, d = 10%

TDA7396

WITH DIAGNOSTIC FACILITY

Multiwatt11

ORDERING NUMBER:

SHORT CIRCUIT
OPEN LOAD
THERMAL SHUTDOWN

PROTECTIONS:

SHORT CIRCUIT ( TO GND, TO VS, ACROSS
THE LOAD)

VERY INDUCTIVE LOADS
CHIP OVER-TEMPERATURE
LOAD DUMP
OPEN GND
ESD

TDA7396

+V

S

7

5

4

GND

100nF

OUT+

OUT-

CD-DIA

0.22µF

IN+

0.22µF

IN-

STANDBY

TO µC or V

April 2002

This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

S

CM

10µF

D93AU004

39

2

1

TDA7396

8

11

10 6

RS

51KΩ

1000µF

Vref

10KΩ

TO µC

1/11

TDA7396

DESCRIPTION

The TDA7396 is a BRIDGE class AB audio power
amplifier especially intended for car radio High
Power applications.
The 2Ω power capability together with the possi­bility to operate eit her in DIFFERENTIAL INPUT
MODE or SINGLE ENDED INPUT MODE makes
it suitable for boosters and high end car r adio ap-

Figure 2: Block Diagram

V

CC1VCC2

39

IN-

IN+

+

-

ST ANDBY THRESHOLD

1

ICM

2

500Ω

500Ω

-

+

gm

REFERENCES

10K

COMMON

MODE

-

+

V

CC/2

10K

plications.
The exclusive fully complementary output stage
and the internally fixed gain configuration drop the
external component count.
The on board clipping detector allows easy imple­mentation of gain compression systems.
The diagnostics facility allows to detect any mis­takes during car radio set assembly and wiring in
the car.

SHORT CIRCUIT

DUMP & THERMAL

PROTECTION

5

POWER AMP

LTS

POWER AMP

DETECT

THD

V=f
(Tj)

LTS

DISABLE

OUT-

4

DIAGN

CD

7

OUT+

+

-

MUTE THRESHOLD

MUTE SYNC GND STANDBY

PIN CONNECTION (Top view)

TAB CONNECTED TO PIN 6

THERMAL DATA

PROGRAMMABLE

CURRENT CIRCUIT

1011 8

11
10

DIAGNOSTIC

CIRCUIT

6

D94AU107

MUTE

SYNC
9
8
7
6
5
4
3
2
1

D93AU003A

+V

S

STAND-BY

OUT+

GND

OUT-

CD-DIA (CLIPPING DETECTOR - DIAG.)

+V

S

IN+

IN-

Symbol Description Value Unit

R

th j-case

Thermal Resistance Junction-case Max 1.5

2/11

C/W

°

TDA7396

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

DC Supply Voltage 28 V

S

Operating Supply Voltage 18 V
Peak Supply Voltage (t = 50ms) 50 V
Output Peak Current repetitive (f > 10Hz)

Output Peak Current non repetitive
Power Dissipation (T

= 85°C) 43 W

CASE

6
7

, TjStorage and Junction-Case -40 to 150

A
A

C

°

T

V

V

V

OP

PEAK

I

P

stg

O

tot

ELECTRICAL CHARACTERISTICS (V

= 14.4V; RL = 2Ω, f = 1KHz, T

S

= 25°C, unless otherwise

amb

specified)

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

S

I

q

V

OS

I

SB

I

SBin

V

SBon

V

SBoff

ATT

ST-BY

R

EXT/RS

I

M in

A

M

P

O

d Distortion PO = 0.1 to 20W

G

V

f

H

R

IN

E

IN

CMRR Input Common Mode Rejection f = 1KHz; V

SVR Supply Voltage Rejection Rg = 0Ω; Vr = 1Vrms 60 dB
CDL Clipping Detection Level 0.5 %

T

sd

Supply Voltage Range 8 18 V
Total Quiescent Current 100 mA
Output Offset Voltage 150 mV
ST-BY Current V
ST-BY Input Bias Current V

= 1.5V 100

ST-BY

= 5V 10

ST-BY

ST-BY On Threshold Voltage 1.5 V
ST-BY Off threshold Voltage 3.5 V
ST-BY Attenuation 90 dB
Mute Resistor Ratio for External

(see Application Circuit of fig. 4) 0.63 0.69 V

Mute Control
Mute Input Bias Current V

= 5V 10

MUTE

Mute Attenuation 90 dB
RMS Output Power d = 10%

d = 1%
d = 10%; R

EIAJ Output Power V

= 13.7V 60 W

S

L

= 4

Ω

45
35
27

0.06

= 0.1 to 15W; RL = 4

P

O

Ω

0.03
Voltage Gain 25 26 27 dB
High Frequency rolloff PO = 1W; -3dB 75 KHz
Input Impedance Differential 60 K

Single Ended 55 K

Input Noise Voltage Rg = 0Ω ; f = 22Hz to 22KHz 4

= 1Vrms 70 dB

IN

Absolute Thermal Shutdown

160 dB

Junction Temperature

A

µ

A

µ

A

µ

W
W
W

%
%

Ω
Ω

V

µ

3/11

TDA7396

FUNCTIONAL DESCRIPTION

Pin Function Description

1, 2 INPUTS

4 CD - DIA

5, 7 OUTPUTS

8 STAND-BY

10 SYNC

11 MUTE

The input stage is a high impedance differential 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.

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)

- 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.
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
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
current that flows into C
required to bias the amplifier.

a) The pin will have a capacitor (C
automatic Mute during turn on/off is provided to prevent noisy transients
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
to reach the fixed limits 0.63 ≤ R

) has to be connect between pin 10 and GND in order to program the

S

capacitor (pin 11). The values of CM and RS determine the time

M

) tied to GND to set the MUTE/STAND-BY time. An

M

/ R

0.69

EXT

≤

S

/ RS in to order

EXT

Figure 3: Application Circuit with External Mute Control

0.22µF

IN+

39

2

0.22µF

IN-

1

TDA7396

TO µC

STANDBY

TO µC or V

S

REXT

8

11

10 6

CM

RS

7

5

4

GND

100nF

OUT+

OUT-

CD-DIA

1000µF

Vref

10KΩ

D93AU007

+V

S

TO µC

4/11

TDA7396

Figure 4: Quiescent Current vs Supply Voltage Figure 5: EIAJ power vs Supply Voltage

RL = 2

Ω

RL = 4

Ω

Figure 6: Output Power vs Supply Voltage (R

RL = 2

Ω

f = 1KHz

Figure 8: Output Power vs Supply Voltage (R

RL = 4

Ω

f = 1KHz

=2Ω)

L

=4Ω)

L

Figure 7: Distortion vs Frequency (R

VS = 14.4V
R

= 2

Ω

L

P

= 18W

O

f (Hz)

Figure 9: Distortion vs Frequency (R

VS = 14.4V
R

= 4

Ω

L

P

= 15W

O

=2Ω)

L

=4Ω)

L

f (Hz)

5/11

TDA7396

Figure 10: Supply Voltage Rejection vs Fre-

quency

VS = 14.4V
V

= 1Vrms

r

R

= 2

Ω

L

R

= 0

g

f (Hz)

Figure 12: Total Power Dissipat ion & Effic iency vs .

Output Power (R

VS = 14.4V
R

= 2

Ω

L

f = 1KHz

= 2Ω)

L

Figure 11: Common Mode Rejection vs. Fre-

quency

VS = 14.4V
V

= 1Vrms

cm

R

= 2

Ω

L

R

= 0

g

f (Hz)

Figure 13: Total Power Dissipation & Efficiency vs.

Output Power (R

= 4Ω)

L

VS = 14.4V
R

= 4

Ω

L

f = 1KHz

6/11

TDA7396

Figure 14: Application Circuit

+V

S

IN+

C2 0.22µF

C1 0.22µF

39

2

C5 100nF

OUT+

7

C4 1000µF

IN-

1

TDA7396

J1

V

S

SW1

D93AU108

Figure 15: P.C. Board and Component Layout (1:1 scale)

ST-BY

C3

10µF

8

11

10 6

R2

51KΩ

5

4

GND

OUT-

CD-DIA

R1 15KΩ

100nF

5V

R3

100KΩ

TO µC

C6

7/11

TDA7396

CLIPPING DETECTION & DIAGNOSTICS

(see fig. 16)
An active pull-down circuit is provided to signal

out the occurrence of any of the conditions de­scribed later. In order to use this function, the CD­DIA pin (#4) has to be resistively connected to a
positive voltage reference (between 5V and Vs).

A) Clipping Detection

Current is sunk whenever the output clipping dis­tortion level reaches a fixed 0.5% threshold; this
function allows gain compression facility when the
amplifier is overdriven.

B) Output Fault Diagnostics
Current is sunk as soon as one of the following

output faults is recognized:

- short-circuit to GND

- short-circuit to Vs

- short-circuit across the load (after turn-on)

- open load (before turn-on)
The diagnostics signal remains steadily on until

the fault is removed.
All the output fault conditions (listed above) can

be distinguished from the clipping detection (A)
because of their different time duration.

THERMAL WARNING (see fig. 17)
Thermal protection has been implemented in ac-

cordance to a new principle involving different
steps:

1) Thermal foldback (Linear Thermal Shutdown)

2) Shutdown with soft restart (Absolute Thermal
Shutdown)

As long as the junction temper ature remains be­low the preset threshold (140°C) the IC delivers
the full power. Once the threshold has been
reached, a thermal foldback starts limiting the out­put signal level; the output power is then reduced,
thus decreasing also the temperature without out­put signal interruption (LTS). Supposing the ther­mal foldback does not reduce the junction tem­perature to a safe level, a complete shutdown will
occur at 160°C (ATS).
Soft restart avoids large voltage disturbance
across the loudspeaker, due to the presence of
high input signals when the IC comes out of ther­mal shutdown.

Current is sunk from the CD-DIA pin (#4)when the
thermal protection is acting. The voltage at pin #4
bounces back and forth (depending on the ampli­fier input signal magnitude ) during t he linear ther­mal intervention (LTS) and stays low (sinking cur­rent) after the amplifier has been eventually
shut-down (Absolute Thermal Shutdown)

Figure 16: Clipping Detection & Diagnostics Waveforms

Vo

CLIPPING

CLIPPING

DETECTOR/

DIAGNOSTICS

OUTPUT

(pin 4)

0

NORMAL OPERATION FAULT DIAGNOSTICS NORMAL OPERATION

8/11

S/C TO GND

D93AU005A

TDA7396

Figure 17: Thermal Protection & Diagnostic Waveforms

MAX OUTPUT

VOLTAGE

SWING

DIAGNOSTICS

OUTPUT

(pin 4)

LINEAR

THERMAL

SHUT DOWN

ABS THERMAL

SHUTDOWN

0

140˚C 160˚C

D93AU006A

9/11

TDA7396

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 5 0.197
B 2.65 0.104
C 1.6 0.063
D 1 0.039
E 0.49 0.55 0.019 0.022
F 0.88 0.95 0.035 0.037

G 1.45 1.7 1.95 0.057 0.067 0.077
G1 16.75 17 17.25 0.659 0.669 0.679
H1 19.6 0.772
H2 20.2 0.795

L 21.9 22.2 22.5 0.862 0.874 0.886
L1 21.7 22.1 22.5 0.854 0.87 0.886
L2 17.4 18.1 0.685 0.713
L3 17.25 17.5 17.75 0.679 0.689 0.699
L4 10.3 10.7 10.9 0.406 0.421 0.429
L7 2.65 2.9 0.104 0.114

M 4.25 4.55 4.85 0.167 0.179 0.191

M1 4.73 5.08 5.43 0.186 0.200 0.214

S 1.9 2.6 0.075 0.102

S1 1.9 2.6 0.075 0.102

Dia1 3.65 3.85 0.144 0.152

mm inch

OUTLINE AND

MECHANICAL DATA

Multiwatt11 V

10/11

TDA7396

Information furnishe d is beli eved to be accu rate and reliable. However, STMicroelec tronics assumes no res ponsibility for the consequences
of use of such i nformation nor for any i nfringement of patents or ot her rights of third par ties which may result from its use. No license i s
granted by impli cation or otherwis e under any patent or patent righ ts of STMicroelect ronics. Specifica tion mentioned in this publication are
subject to change without notic e. This public ation supers edes and replaces all information prev iously supplied. STMic roelec tronic s products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

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11/11