Datasheet TDA7296AV, TDA7296A Datasheet (SGS Thomson Microelectronics)

TDA7296A

70V - 60W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY

PRODUCT PREVIEW

VERY HIGH OPERATING VOLTAGE RANGE
(±35V)

DMOSPOWERSTAGE
HIGH OUTPUT POWER (UP TO 60W MUSIC

POWER)
MUTING/STAND-BYFUNCTIONS
NO SWITCH ON/OFFNOISE
NO BOUCHEROTCELLS
VERYLOW DISTORTION
VERYLOW NOISE
SHORTCIRCUITPROTECTION
THERMALSHUTDOWN
CLIPPINGDETECTION OUTPUT

DESCRIPTION

The TDA7296A is a monolithic integrated circuit
in Multiwatt15 package, intended for use as audio
class AB amplifier in Hi-Fi field applications
(Home Stereo, self powered loudspeakers, Top­class TV). Thanks to the wide voltage range and
to the high out current capability it is able to sup­ply the highest power into both 4Ω and 8Ω loads

Figure 1: Typical Applicationand Test Circuit

MULTIPOWER BCD TECHNOLOGY

Multiwatt 15

ORDERING NUMBER: TDA7296AV

even in presence of poor supply regulation, with
high Supply Voltage Rejection.

The built in muting function with turn on delay
simplifiesthe remote operation avoidingswitching
on-off noises.

The device provides a circuit for the detection of
clipping in the output stages. The output, on open
collector, is able to drive system with automatic
levelcontrol.

+VsC7 100nF C6 1000µF

R3 22K

+PWVs+Vs

CD

S/C

PROTECTION

158

-Vs

VM

VSTBY

C2

R2

22µF

680Ω

C1 470nF

R1 22K

R5 10K

R4 22K

C3 10µFC410µF

IN- 2

IN+

IN+MUTE

MUTE

STBY

3

4

10
9

MUTE

STBY

1
STBY-GND

713

-

+

THERMAL

SHUTDOWN

-Vs -PWVs

C9 100nF C8 1000µF

June 1996

This is preliminaryinformationon a new productnow in development. Details aresubject to change withoutnotice.

14

6
5

D96AU494

OUT

C5

22µF

BOOTSTRAP

+5V

1/13

TDA7296A

PIN CONNECTION (Topview)

BLOCK DIAGRAM

15
14
13
12
11
10

9
8
7
6
5
4
3
2
1

BOOTSTRAP

D96AU495

-V

(POWER)

S

OUT
+V

(POWER)

S

N.C.
N.C.
MUTE
STAND-BY

(SIGNAL)

-V

S

+V

(SIGNAL)

S

BOOTSTRAP
CD
SVR
NON INVERTING INPUT
INVERTING INPUT
STAND-BY GND

+

-

+

+V

S

BOOTSTRAP

IN+

OUTPUT

IN-

BIPOLAR

TRANSCONDUCTANCE

INPUT STAGE

MOS GAIN &

LEVEL SHIFTING

STAGE

MOS OUTPUT STAGE SHORT CIRCUIT

CD

+

-

+

PROTECTION

CD

-V

D96AU496

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

I

O

P

tot

T

op

T

stg,Tj

Supply Voltage

S

Output Peak Current 5 A
Power Dissipation T

=70°C50W

case

Operating Ambient Temperature Range 0 to 70
Storage and Junction Temperature 150

2/13

35 V

±

S

C

°

C

°

TDA7296A

THERMAL DATA

Symbol Description Value Unit

R

th j-case

Thermal Resistance Junction-case Max 1.5

C/W

°

ELECTRICALCHARACTERISTICS

R

=50Ω;T

g

=25°C,f = 1 kHz; unlessotherwisespecified.

amb

(Refer to the Test Circuit V

= ±24V, RL=8Ω,GV= 30dB;

S

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

I
I

V

I

OS

P

Operating Supply Range ±10 ±35 V

S

Quiescent Current 20 30 60 mA

q

Input Bias Current 500 nA

b

Input Offset Voltage +10 mV

OS

Input Offset Current +100 nA
RMS Continuous Output Power d = 0.5%:

O

Music Power (RMS) (*)

t=1s

∆

d Total Harmonic Distortion (**) P

V

=±24V,RL=8

S

V

=±21V, RL=6Ω

S

ς

=±18V, RL=4Ω

S

Ω

d = 10%;
R

=8Ω ;VS=±29V

L

R

=6Ω ;VS=±24V

L

R

=4Ω;VS=±22V

L

= 5W; f = 1kHz

O

P

=0.1to 20W; f= 20Hzto20kHz

O

=±18V, RL=4

V

S

P

= 5W; f = 1kHz

O

P

=0.1to 20W; f= 20Hzto20kHz

O

Ω:

27
27
27

30
30
30

60
60
60

0.005

0.01

0.1

0.1

W
W
W

W
W
W

%
%

%

%
SR Slew Rate 7 10 V/µs
G
G

e

f

L,fH

R

SVR Supply Voltage Rejection f = 100Hz; V

T

STAND-BY FUNCTION (Ref: -V

V

ST on

V

ST off

ATT

I

q st-by

MUTE FUNCTION (Ref: -V

V

Mon

V

Moff

ATT

DC Off Clipping detector OFF.

Open Loop Voltage Gain 80 dB

V

Closed Loop Voltage Gain 24 30 40 dB

V

Total Input Noise A = curve

N

f = 20Hz to 20kHz

1

25
Frequency Response (-3dB) PO= 1W 20Hz to 20kHz
Input Resistance 100 kΩ

i

= 0.5Vrms 60 75 dB

ripple

Thermal Shutdown 145

S

or GND)

S

Stand-by on Threshold 1.5 V
Stand-by off Threshold 3.5 V
Stand-by Attenuation 70 90 dB

st-by

Quiescent Current @ Stand-by 1 3 mA

or GND)

S

Mute on Threshold 1.5 V
Mute off Threshold 3.5 V
Mute AttenuatIon 60 80 dB

mute

THD = 1% TBD %

µV

V

µ

C

°

CD output Duty Cycle

DC On Clipping detector On.

THD = 10% TBD %

CD output Duty Cycle

Note (*):

MUSIC POWERis the maximalpower which the amplifieris capableof producing across therated load resistance (regardless ofnon linearity)
1 sec after the applicationofasinusoidalinput signal of frequency 1KHz.

Note (**): Tested with optimized ApplicationBoard (see fig. 2)

3/13

TDA7296A

Figure 2:

P.C.B.and componentslayout of thecircuit of figure 1. (1:1 scale)

TDA7296A

Note:

The Stand-by and Mute functions canbe referred eitherto GND or -VS.
On the P.C.B. is possibletosetboth the configuration throughthe jumperJ1.

4/13

TDA7296A

APPLICATIONSUGGESTIONS(seeTestand Application Circuitsof the Fig. 1)

The recommended values of the external components are those shown on the application circuit of Fig­ure 1. Different values can be used;the following table can help the designer.

COMPONENTS SUGGESTED VALUE PURPOSE

R1 (*) 22k INPUT RESISTANCE INCREASE INPUT

R2 680

R3 (*) 22k INCREASE OF GAIN DECREASE OF GAIN

R4 22k ST-BY TIME

R5 10k MUTE TIME

C1 0.47µF INPUT DC

C2 22µF FEEDBACK DC

C3 10µF MUTE TIME

C4 10µF ST-BY TIME

Ω

CLOSED LOOP GAIN

SET TO 30dB (**)

CONSTANT

CONSTANT

DECOUPLING

DECOUPLING

CONSTANT

CONSTANT

LARGER THAN

SUGGESTED

IMPRDANCE

DECREASE OF GAIN INCREASE OF GAIN

LARGER ST-BY

ON/OFF TIME

LARGER MUTE

ON/OFF TIME

LARGER MUTE

ON/OFF TIME

LARGER ST-BY

ON/OFF TIME

SMALLER THAN

SUGGESTED

DECREASE INPUT

IMPEDANCE

SMALLER ST-BY

ON/OFF TIME;

POP NOISE

SMALLER MUTE

ON/OFF TIME
HIGHER LOW

FREQUENCY

CUTOFF

HIGHER LOW
FREQUENCY

CUTOFF

SMALLER MUTE

ON/OFF TIME

SMALLER ST-BY

ON/OFF TIME;

POP NOISE

C5 22µF BOOTSTRAPPING SIGNAL

C6, C8 1000µF SUPPLY VOLTAGE

C7, C9 0.1µF SUPPLY VOLTAGE

(*) R1 = R3 FOR POP OPTIMIZATION
(**) CLOSED LOOP GAINHAS TO BE≥24dB

BYPASS

BYPASS

DEGRADATION AT
LOW FREQUENCY

DANGER OF

OSCILLATION

DANGER OF

OSCILLATION

5/13

TDA7296A

TYPICALCHARACTERISTICS

(ApplicationCircuit of fig 1 unless otherwise specified)

Figure 3:

OutputPowervs. Supply Voltage.

Figure 5: OutputPower vs. Supply Voltage

Figure4:

Distortionvs. Output Power

Figure6: Distortionvs.OutputPower

Figure 7: Distortionvs.Frequency

6/13

Figure8: Distortionvs.Frequency

TYPICALCHARACTERISTICS (continued)

TDA7296A

Figure 9:

Figure 11:

QuiescentCurrent vs. Supply Voltage

MuteAttenuationvs. V

pin10

Figure10:

SupplyVoltageRejectionvs.Frequency

Figure12: St-byAttenuationvs. V

pin9

Figure 13: Power Dissipationvs. OutputPower

Figure14:

PowerDissipation vs. OutputPower

7/13

TDA7296A

INTRODUCTION

In consumer electronics, an increasing demand
has arisen for very high power monolithic audio
amplifiers able to match,with a low cost the per­formance obtained from the best discrete de­signs.

The task of realizing this linear integrated circuit
in conventional bipolar technology is made ex­tremely difficult by the occurence of 2nd break­down phenomenon. It limits the safe operating
area (SOA) of the power devices, and as a con­sequence, the maximum attainableoutput power,
especiallyin presence of highly reactive loads.

Moreover, full exploitation of the SOA translates
into a substantial increase in circuit and layout
complexity due to the need for sophisticated pro­tection circuits.

To overcome these substantial drawbacks, the
use of power MOS devices, which are immune

monic distortion and good behaviour over fre­quency response; moreover, an accurate control
of quiescent current is required.

A local linearizing feedback, provided by differen­tial amplifier A, is used to fullfilthe above require­ments, allowing a simple and effective quiescent
currentsetting.

Proper biasing of the power output transistors
alone is howevernot enough to guaranteethe ab­senceof crossoverdistortion.

While a linearization of the DC transfer charac­teristic of the stage is obtained, the dynamic be­haviour of thesystem must be taken into account.

A significant aid in keeping the distortion contrib­uted by the final stage as low as possible is pro­vided by the compensation scheme, which ex­ploits the direct connection of the Miller capacitor
at the amplifier’s output to introduce a local AC

feedbackpathenclosing the output stage itself.
from secondarybreakdownis highly desirable.
The device described has therefore been devel-

oped in a mixed bipolar-MOS high voltage tech­nology called BCD 80.

2) Protections

In designing a power IC, particular attention must

be reserved to the circuits devoted to protection

of the device from short circuit or overload condi-

1) OutputStage

The main design task one is confrontedwith while
developing an integrated circuit as a power op­erational amplifier, independently of the technol­ogy used, is that of realising the outputstage.

The solution shown as a principle schematic by
Fig 15 represents the DMOS unity-gain output
buffer of the TDA7296A.

This large-signal, high-power buffer must be ca­pable of handling extremely high current and volt­age levels while maintaining acceptably low har-

tions.

Due to the absence of the 2nd breakdown phe-

nomenon, the SOA of the power DMOS transis-

tors is delimited only by a maximum dissipation

curve dependent on the duration of the applied

stimulus.

In order to fully exploit the capabilities of the

power transistors, the protection scheme imple-

mented in this device combines a conventional

SOA protection circuit with a novel local tempera-

ture sensing technique which ” dynamically” con-

trols the maximumdissipation.
Figure 15: PrincipleSchematicof a DMOS unity-gain buffer.

8/13

Figure 16: Turn ON/OFF SuggestedSequence

+Vs

(V)

+35

-35

-Vs

VIN

(mV)

V

ST-BY

PIN #9

(V)

5V

TDA7296A

V

MUTE

PIN #10

(V)

IP

(mA)

V

OUT
(V)

5V

OFF

ST-BY

PLAY

MUTE MUTE

In addition to the overload protection described
above, the device features a thermal shutdown
circuit which initially puts the device into a muting
state (@ Tj = 145

Figure 17:

SingleSignalST-BY/MUTEControl

o

C) and then into stand-by (@

Circuit

MUTE STBY

MUTE/

ST-BY

20K

10K 30K

1N4148

10µF10µF

D93AU014

ST-BY OFF

D93AU013

o

Tj = 150

C).

Full protection against electrostatic discharges on

everypin is included.

3) OtherFeatures

The device is provided with both stand-by and

mute functions, independently driven by two

CMOSlogiccompatibleinput pins.

The circuits dedicated to the switching on and off

of the amplifier have been carefully optimized to

avoid any kindof uncontrolled audibletransient at

the output.

The sequence that we recommend during the

ON/OFFtransientsisshown by Figure 16.

The application of figure 17 shows the possibility

of using only one command for both st-by and

mute functions. On both the pins, the maximum

applicable range corresponds to the operating

supplyvoltage.

9/13

TDA7296A

4) ClippingDetectorOutput

The TDA7296A is equipped with an internal cir­cuit able to detect the output stage saturation pro­viding a proper current sinking into on open col­lector output (pin 5) when a certain distortion level
is reachedat output.

This particular function allows gain compression
facility whenever the amplifier is overdriven, thus
obtaining high quality sound all listening levels.

Figure 18:

ClippingDetectorOutput Waveform

V

O

I

CLIP

S96AU498

OUTPUT

SIGNAL

t

Figure 19: Bridge ApplicationCircuit

BRIDGEAPPLICATION

Another application suggestion is the BRIDGE

configuration, where two TDA7296A are used, as

shownby the schematic diagram of figure 19.

In this application, the value of the load must not

be lower than 8 Ohm for dissipation and current

capabilityreasons.

A suitable field of application includes HI-FI/TV

subwoofersrealizations.

The main advantagesofferedby this solution are:

- High power performanceswith limited supply
voltagelevel.

- Considerablyhigh output power even with high
loadvalues (i.e. 16 Ohm).

The characteristics shown by figures 21 and 22,
measured with loads respectively 8 Ohm and 16
Ohm.

With Rl= 8 Ohm, Vs = ±18V the maximum output
power obtainable is 60W, while with Rl=16 Ohm,
Vs = ±24V the maximumPout is 60W.

+Vs

Vi

ST-BY/MUTE

10K 30K

20K

22µF

1N4148

0.56µF 22K

22K0.56µF

2200µF0.22µF

22µF

3

1
4

10

10

3

1
4

9

9

137

+

-

15 8

+

-

137

6

22µF

14

2

815

2200µF 0.22µF

6

14

2

22K

680

22µF

22K

680

22K

-Vs

10/13

D96AU497

TDA7296A

Figure 20:

FrequencyResponseof the Bridge

Application

Figure 22: Distortionvs.OutputPower

Figure21: Distortionvs.OutputPower

11/13

TDA7296A

MULTIWATT15 PACKAGE MECHANICAL DATA

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 0.66 0.75 0.026 0.030

G 1.14 1.27 1.4 0.045 0.050 0.055
G1 17.57 17.78 17.91 0.692 0.700 0.705
H1 19.6 0.772
H2 20.2 0.795

L 22.1 22.6 0.870 0.890
L1 22 22.5 0.866 0.886
L2 17.65 18.1 0.695 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 4.2 4.3 4.6 0.165 0.169 0.181

M1 4.5 5.08 5.3 0.177 0.200 0.209

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

12/13

TDA7296A

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patentrightsof SGS-THOMSON Microelectronics. Specification mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS­THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectronics.

 1996SGS-THOMSON Microelectronics– Printed in Italy– All Rights Reserved

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