E-TDA7377A - STMicroelectronics - Datasheet.Directory

TDA7377

2x30W DUAL/QUAD POWER AMPLIFIER FOR CAR RADIO

HIGHOUTPUT POWER CAPABILITY:

2x35W max./4Ω

2x30W/4ΩEIAJ

2x20W/4Ω@14.4V,1KHz,10%

4x6W/4Ω@14.4V,1KHz,10%

4x10W/2Ω@14.4V,1KHz, 10%

MINIMUM EXTERNAL COMPONENTS

COUNT:

– NOBOOTSTRAP CAPACITORS

– NOBOUCHEROTCELLS

– INTERNALLYFIXEDGAIN (26dB BTL)

ST-BY FUNCTION (CMOSCOMPATIBLE)

NOAUDIBLEPOPDURINGST-BYOPERATIONS

DIAGNOSTICSFACILITYFOR:

– CLIPPING

– OUTTO GND SHORT

– OUTTO VSSHORT

– SOFTSHORTAT TURN-ON

– THERMALSHUTDOWN PROXIMITY

Protections:

OUPUTAC/DC SHORT CIRCUIT

–TOGND

–TOV

– ACROSSTHE LOAD

SOFTSHORTAT TURN-ON

OVERRATING CHIP TEMPERATURE WITH

SOFTTHERMAL LIMITER

LOADDUMP VOLTAGESURGE

VERYINDUCTIVE LOADS

FORTUITOUSOPEN GND

REVERSEDBATTERY

ESD

September 1998



BLOCK DIAGRAM

MULTIWATT15V MULTIWATT15H

ORDERING NUMBERS:

TDA7377V TDA7377H

DIAGNOSTICS

1/10

DESCRIPTION

The TDA7377is a new technology class AB car

radio amplifier able to work either in DUAL

BRIDGEor QUADSINGLEENDED configuration.

The exclusive fully complementarystructureof the

output stage and the internally fixed gain guaran-

tees the highest possible power performances

with extremely reduced component count. The

on-boardclip detectorsimplifies gain compression

operation. The fault diagnosticsmakes it possible

to detect mistakes during car radio set assembly

and wiring in the car.

GENERAL STRUCTURE

ABSOLUTEMAXIMUM RATINGS

Symbol Parameter Value Unit

Vop Operating Supply Voltage 18 V

VSDC Supply Voltage 28 V

Vpeak Peak Supply Voltage (for t = 50ms) 50 V

IOOutput PeakCurrent (notrepetitive t = 100µs) 4.5 A

IOOutput Peak Current (repetitive f > 10Hz) 3.5 A

Ptot Power Dissipation (Tcase =85°C) 36 W

Tstg,T

jStorage and Junction Temperature -40 to 150 °C

THERMAL DATA

Symbol Description Value Unit

Rth j-case Thermal Resistance Junction-case Max 1.8 °C/W

PIN CONNECTION (Topview)

DIAGNOSTICS

TDA7377

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ELECTRICAL CHARACTERISTICS (Referto the test circuit, VS= 14.4V;RL=4

Ω; f = 1KHz;

Tamb =25°C,unlessotherwise specified

Symbol Parameter Test Condition Min. Typ. Max. Unit

VSSupply Voltage Range 8 18 V

IdTotal Quiescent Drain Current RL=∞150 mA

VOS Output Offset Voltage 150 mV

POOutput Power THD = 10%; RL=4

Ω

Bridge

Single Ended

Single Ended, RL=2

Ω

5.5 20

POmax Max. Output Power (***) VS = 14.4V, Bridge 31 35 W

PO EIAJ EIAJ Output Power (***) VS= 13.7V, Bridge 27 30W

THD Distortion RL=4Ω

Single Ended, PO= 0.1 to 4W

Bridge, PO= 0.1 to 10W 0.02

0.03 0.3 %

CT Cross Talk f = 1KHz Single Ended

f = 10KHz Single Ended 70

60 dB

f = 1KHz Bridge

f = 10KHz Bridge 55 60 dB

RIN Input Impedance Single Ended

Bridge 20

10 30

15 KΩ

KΩ

GVVoltage Gain Single Ended

Bridge 19

25 20

26 21

27 dB

GVVoltage Gain Match 0.5 dB

EIN Input Noise Voltage Rg= 0; ”A” weighted, S.E.

Non Inverting Channels

Inverting Channels 2

5µV

µV

Bridge

Rg = 0; 22Hz to 22KHz 3.5 µV

SVR Supply Voltage Rejection Rg= 0; f = 300Hz 50 dB

ASB Stand-by Attenuation PO=1W 80 90 dB

ISB ST-BY Current Consumption VST-BY = 0 to 1.5V 100 µA

VSB ST-BY In Threshold Voltage 1.5 V

VSB ST-BY Out Threshold Voltage 3.5 V

Ipin7 ST-BY Pin Current Play ModeVpin7 =5V 50 µA

Max Driving Current Under

Fault(*) 5mA

Icd off Clipping Detector

Output AverageCurrent d = 1% (**) 90 µA

Icd on Clipping Detector

Output AverageCurrent d = 5% (**) 160 µA

Vsat pin10 Voltage Saturation on pin 10 Sink Current at Pin 10 = 1mA 0.7 V

(*) See built-in S/C protection description

(**) Pin 10 Pulled-up to 5V with 10KΩ;R

L=4Ω

(***) Saturatedsquare wave output.

TDA7377

3/10

C1 0.22µF

DIAGNOSTICS

C10 2200µF

D94AU063A

10µF

10K R1

ST-BY

IN FL

C2 0.22µF

IN FR 5

C4 0.22µF

12IN RL

C3 0.22µF

IN RR 11

C8 47µF

1000µF

100nF

C9 2200µF

C11 2200µF

C12 2200µF

OUT FL

OUT FR

OUT RL

OUT RR

89 10

STANDARD TEST ANDAPPLICATION CIRCUIT

Figure 1: Quad Stereo

C1 0.47µF

DIAGNOSTICS

D94AU064A

10µF

10K R1

ST-BY

IN L

C2 0.47µF

12IN R

C8 47µF

1000µF

100nF

OUT L

89 10

OUT R

Figure 2: Double Bridge

0.22µF

DIAGNOSTICS

D94AU065A

10µF

10K

ST-BY

IN L

0.47µF

IN BRIDGE 12

47µF

1000µF100nF

OUT L

89 10

OUT

BRIDGE

0.22µF

IN L OUT R

2200µF

Figure 3: Stereo/Bridge

Note:

C9, C10, C11, C12 could be

reduced if the 2Ωoperation is not

required.

TDA7377

4/10

High ApplicationFlexibility

The availability of 4 independentchannels makes

it possible to accomplish several kinds of applica-

tions ranging from 4 speakers stereo (F/R) to 2

speakersbridge solutions.

In case of working in single ended conditions the

polarity of the speakers driven by the inverting

amplifier must be reversedrespect to those driven

by non inverting channels.

This is to avoid phase inconveniences causing

sound alterations especially during the reproduc-

tionof low frequencies.

Easy SingleEnded to Bridge Transition

The change from single ended to bridge configu-

rations is made simply by means of a short circuit

across the inputs, that is no need of furtherexter-

nal components.

Gain Internally Fixed to 20dB in Single Ended,

26dB inBridge

Advantagesof thisdesign choice are in terms of:

componentsand space saving

output noise, supply voltage rejection and dis-

tortionoptimization.

Silent Turn On/Off and Muting/Stand-by Func-

tion

The stand-by can be easily activated by means of

a CMOS level applied to pin 7 through a RC filter.

Under stand-by condition the device is turned off

completely (supply current = 1µA typ.; output at-

tenuation= 80dB min.).

Every ON/OFFoperationis virtually pop free.

Furthemore, at turn-on the device stays in muting

condition for a time determined by the value as-

signed to theSVR capacitor.

While in muting the device outputs becomes in-

sensitive to any kinds of signal that may be pre-

sent at the input terminals. In other words every

transient coming from previous stages produces

no unplesantacoustic effectto the speakers.

STAND-BYDRIVING (pin 7)

Some precautions have to be taken in the defini-

tion of stand-by driving networks: pin 7 cannot be

directly driven by a voltagesource whose current

capability is higher than 5mA. In practical cases

a series resistance has always to be inserted,

having it the double purpose of limiting the cur-

rent at pin 7 and to smooth down the stand-by

ON/OFF transitions - in combination with a ca-

pacitor - for output pop prevention.

In any case, a capacitor of at least 100nF from

pin 7 to S-GND, with no resistance in between, is

necessary to ensure correct turn-on.

OUTPUT STAGE

The fully complementary output stage was made

possible by the development of a new compo-

nent: the ST exclusivepower ICV PNP.

A novel design based upon the connectionshown

in fig. 20 has then allowed the full exploitation of

its possibilities.

The clear advantagesthis new approachhas over

classicaloutput stagesare as follows:

Rail-to-Rail Output Voltage Swing With No

Need of Bootstrap Capacitors.

The outputswing is limited only by the VCEsat

of the output transistors, which is in the range

of 0.3Ω(Rsat) each.

Classical solutions adopting composite PNP-

NPN for the upper output stage have higher

saturationloss on the top side of the waveform.

This unbalanced saturation causes a signifi-

cant power reduction. The only way to recover

power consists of the addition of expensive

bootstrapcapacitors.

Absolute Stability Without Any External

Compensation.

Referring to the circuit of fig. 20 the gain

VOut/VIn is greater than unity, approximately1+

R2/R1. The DC output (VCC/2) is fixed by an

auxiliary amplifier common to allthe channels.

Bycontrollingtheamountof thislocal feedbackit

is possible to force the loop gain (A*β)toless

thanunity at frequencyfor which the phase shift

is 180°. This means that the output buffer is in-

trinsicallystableand notproneto oscillation.

Most remarkably, the above feature has been

achieved in spite of the very low closed loop

gain of the amplifier.

In contrast, with the classical PNP-NPN stage,

the solution adopted for reducing the gain at

high frequencies makes use of external RC

networks,namely the Boucherotcells.

BUILT–IN SHORTCIRCUIT PROTECTION

Figure20: TheNew OutputStage

TDA7377

5/10

Reliable and safe operation, in presence of all

kinds of short circuit involving the outputs is as-

sured by BUILT-IN protectors. Additionally to the

AC/DC short circuit to GND, to VS, across the

speaker, a SOFT SHORT condition is signalled

out duringthe TURN-ON PHASE so assuringcor-

rect operation for the device itself and for the

loudspeaker.

This particular kind of protection acts in a way to

avoid that the device is turned on (by ST-BY)

when a resistive path (less than 16 ohms) is pre-

sent between the output and GND. As the in-

volved circuitry is normally disabled when a cur-

rent higher than 5mA is flowing into the ST-BY

pin, it is important, in order not to disable it, to

have the external current source driving the ST-

BY pin limited to 5mA.

This extra functionbecomes particularly attractive

when, in the single ended configuration, one ca-

pacitor is shared between two outputs (see fig.

21).

Supposing that the output capacitor Cout for any

reason is shorted, the loudspeaker will not be

damaged being this soft short circuit condition re-

vealed.

DiagnosticsFacility

The TDA7377is equipped with a diagnostic cir-

cuitry able to detect the followingevents:

Clipping in the outputsignal

Thermalshutdown

Outputfault:

– shortto GND

– shortto VS

– softshortat turnon

The information is available across an open

collector output (pin 10) through a current sink-

ing when the event is detected

A current sinking at pin 10 is triggered when a

certain distortion level is reached at any of the

outputs. This function allows gain compression

possibility whenever the amplifieris overdriven.

ThermalShutdown

In this case the output 10 will signal the proximity

of the junction temperature to the shutdown

threshold. Typically current sinking at pin 10 will

start ~10°C before the shutdown threshold is

reached.

HANDLING OF THE DIAGNOSTICS INFORMA-

Figure 21.

Figure22: ClippingDetectionWaveforms

Figure23: OutputFault Waveforms (seefig. 24)

TDA7377

6/10

TION

As various kinds of information is available at the

same pin (clipping detection, output fault, thermal

proximity),this signal must be handled properly in

orderto discriminate each event.

This could be done by takinginto account the dif-

ferent timing of the diagnostic output during each

case.

SOFT SHORT

OUT TO Vs SHORT

FAULT DETECTION

CORRECT TURN-ON

OUT TO GND SHORT

ST-BY PIN

VOLTAGE

OUTPUT

WAVEFORM

Vpin 10

CHECK AT

TURN-ON

(TEST PHASE) SHORT TO GND

OR TO Vs

D94AU149A

Figure 24: FaultWaveforms

ST-BY PIN

VOLTAGE

OUTPUT

WAVEFORM

Vpin

WAVEFORM

SHORT TO GND

OR TO Vs

D94AU150

CLIPPING THERMAL

PROXIMITY

Figure 25: Waveforms

TDA7377

7/10

Normally the clip detector signalling produces a

low level at pin 10 thatis shorter than that present

under faulty conditions; based on this assumption

an interface circuitry to differentiate the informa-

tionis representedin theschematicof fig. 26.

Figure 26.

TDA7377

PCB-LAYOUT GROUNDING (general rules)

The device has 2 distinct ground leads, P-GND

(POWER GROUND) and S-GND (SIGNAL

GROUND) which are practically disconnected

from each other at chip level. Proper operationre-

quires that P-GND and S-GND leads be con-

nected together on the PCB-layout by means of

reasonablylow-resistance tracks.

As for the PCB-ground configuration, a star-like

arrangement whose center is represented by the

supply-filtering electrolytic capacitor ground is

highly advisable. In such context, at least 2 sepa-

rate paths have to be provided, one for P-GND

and one for S-GND. The correct ground assign-

mentsare as follows:

STANDBY CAPACITOR, pin 7 (or any other

standbydriving networks): on S-GND

SVR CAPACITOR (pin 6): on S-GND and to be

placed as close as possible to the device.

INPUT SIGNAL GROUND (from active/passive

signal processorstages):on S-GND.

SUPPLY FILTERING CAPACITORS (pins 3,13):

on P-GND. The (-) terminal of the electrolytic ca-

pacitor has to be directly tied to the battery(-) line

and this should represent the starting point for all

the ground paths.

TDA7377

8/10

Multiwatt15 V

DIM. mm inch

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

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 1.02 1.27 1.52 0.040 0.050 0.060

G1 17.53 17.78 18.03 0.690 0.700 0.710

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 0.870

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 4.25 4.55 4.85 0.167 0.179 0.191

M1 4.63 5.08 5.53 0.182 0.200 0.218

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

OUTLINE AND

MECHANICAL DATA

TDA7377

9 /10

DIM. mm inch

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

0.197

B 2.65 0.104

C 1.6 0.063

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 20.57 0.810

L1 18.03

0.710

L2 2.54

0.100

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

L5 5.28 0.208

L6 2.38

0.094

L7 2.65 2.9 0.104 0.114

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 Multiwatt15 H

OUTLINE AND

MECHANICAL DATA

TDA7377

10/10