SGS Thomson Microelectronics TDA7296S Datasheet

TDA7296S
60V - 60W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY
VERY HIGH OPERATING VOLTAGE RANGE (±30V)
DMOSPOWER STAGE HIGH OUTPUT POWER (THD = 10%, UP TO
60W) MUTING/STAND-BY FUNCTIONS NO SWITCHON/OFFNOISE VERY LOW DISTORTION VERY LOW NOISE SHORTCIRCUIT PROTECTION THERMAL SHUTDOWN CLIPDETECTOR MODULARITY (MORE DEVICES CAN BE
EASILY CONNECTED IN PARALLEL TO DRIVEVERY LOW IMPEDANCES)
DESCRIPTION
The TDA7296S 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, Top-
Figure1: Typical Application andTest Circuit
MULTIPOWERBCD TECHNOLOGY
Multiwatt15
ORDERING NUMBER: TDA7296SV
class TV). Thanks to the wide voltage range and to the high out current capability it is able to sup­ply the highest powerinto both4and8loads.
The built in muting function with turn on delay simplifiesthe remote operation avoiding switching on-off noises. Parallel mode is made possible by connecting more device through of pin11. High output power can be delivered to very low impedance loads,so optimizingthe thermal dissipationof the system.
VMUTE
VSTBY
June 2000
C7 100nF C6 1000µF
R3 22K
C2
R2
22µF
680
C1 470nF
R1 22K
R5 10K
R4 22K
C3 10µFC410µF
IN- 2
IN+
3
4
SGND (**)
10
MUTE
9
STBY
(*) see Application (**) for SLAVE function
note
MUTE
STBY
1 STBY-GND
+Vs
BUFFER DRIVER
713
11
-
+
THERMAL
SHUTDOWN
-Vs -PWVs
C9 100nF C8 1000µF
+PWVs+Vs
PROTECTION
158
-Vs
S/C
14
12
6 5
D97AU805A
OUT
BOOT LOADER
C5
22µF
BOOTSTRAP
CLIP DET
(*)
VCLIP
1/11
TDA7296S
PIN CONNECTION (Top view)
TAB CONNECTED TO PIN 8
15 14 13 12 11 10
9 8 7 6 5 4 3 2 1
D97AU806
-V
(POWER)
S
OUT
(POWER)
+V
S
BOOTSTRAP LOADER BUFFER DRIVER MUTE STAND-BY
-V
(SIGNAL)
S
+VS(SIGNAL) BOOTSTRAP CLIP AND SHORT CIRCUIT DETECTOR SIGNAL GROUND NON INVERTING INPUT INVERTING INPUT STAND-BY GND
QUICK REFERENCEDATA
Symbol Parameter Test Conditions Min. Typ. Max. Unit
V
G
LOOP
P
tot
SVR Supply Voltage Rejection 75 dB
Supply Voltage Operating ±12 ± 30 V
S
Closed Loop Gain 26 40 dB Output Power VS=±30V; RL=8Ω; THD = 10% 60 W
= ±25V; RL =4Ω; THD = 10% 60 W
V
S
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V V V
2 -V3 Maximum Differential Inputs ±30 V
V
V V V V V
V
10 11 Buffer Voltage Referredto -VS 60 V
V
12 Bootstrap Loader Voltage Referred to -VS 60 V
V
I
O
P
tot
T
op
T
stg,Tj
Supply Voltage (No Signal) ±35 V
S
VSTAND-BY GND Voltage Referred to -VS (pin 8) 60 V
1
Input Voltage (inverting) Referred to -V
2
3 Input Voltage (non inverting) Referred to-VS 60 V
Signal GND Voltage Referredto -V
4
Clip Detector Voltage Referred to -V
5 6 Bootstrap Voltage Referred to -VS 60 V 9 Stand-by Voltage Referredto -VS 60 V
Mute Voltage Referred to -V
S
S
S
S
60 V
60 V 60 V
60 V
Output Peak Current 10 A Power Dissipation T
=70°C50W
case
Operating Ambient Temperature Range 0to 70 °C Storage and JunctionTemperature 150 °C
THERMALDATA
Symbol Description Typ Max Unit
R
th j-case
Thermal Resistance Junction-case 1 1.5 °C/W
2/11
TDA7296S
ELECTRICAL CHARACTERISTICS (Referto the Test Circuit VS= ±24V,RL=8,GV= 30dB;
R
=50Ω;T
g
Symbol Parameter Test Condition Min. Typ. Max. Unit
V
S
I
q
I
b
V
OS
I
OS
P
O
d Total Harmonic Distortion (**) P
SR Slew Rate 7 10 V/µs
G
V
G
V
e
N
f
L,fH
R
i
SVR Supply Voltage Rejection f = 100Hz; V
T
S
STAND-BY FUNCTION (Ref: -V
V
ST on
V
ST off
ATT
st-by
I
q st-by
MUTE FUNCTION (Ref: -V
V
Mon
V
Moff
ATT
mute
Note (**):
MUSIC POWER is themaximal power which the amplifieris capable of producing across the rated load resistance (regardless of non linearity) 1 sec after the applicationof a sinusoidal input signal of frequency 1KHz.
Note (**): Tested withoptimized Application Board (see fig. 2)
=25°C,f = 1 kHz; unlessotherwisespecified).
amb
Operating Supply Range ±10 ±30 V Quiescent Current 20 30 60 mA Input Bias Current 500 nA Input Offset Voltage ±10 mV Input Offset Current ±100 nA RMS Continuous OutputPower d = 0.5%:
W W W
W W W
% %
% %
Music Power (RMS) (*)
t=1s
V
= ± 24V, RL=8
S
V
=±21V, RL=6
S
V
=±18V, RL=4
S
d = 10%; R
=8Ω ;VS=±30V
L
R
=6Ω ;VS=±24V
L
R
=4Ω;VS=±23V
L
= 5W; f = 1kHz
O
P
=0.1to20W;f = 20Hzto 20kHz
O
= ±18V, RL=4Ω:
V
S
P
= 5W; f = 1kHz
O
P
=0.1to20W;f = 20Hzto 20kHz
O
27 27 27
30 30 30
60 60 60
0.005
0.1
0.01
0.1
Open Loop Voltage Gain 80 dB Closed Loop Voltage Gain 24 30 40 dB Total Input Noise A = curve
f = 20Hz to 20kHz
1 25
µV µV
Frequency Response (-3dB) PO= 1W 20Hz to 20kHz Input Resistance 100 k
= 0.5Vrms 60 75 dB
ripple
Thermal Shutdown 150
or GND)
S
°
Stand-by on Threshold 1.5 V Stand-by off Threshold 3.5 V Stand-by Attenuation 70 90 dB 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
C
3/11
TDA7296S
Figure2: Typical ApplicationP.C. Board and ComponentLayout (scale1:1)
4/11
TDA7296S
APPLICATION SUGGESTIONS(seeTest and Application Circuits of 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 followingtable can helpthe designer.
COMPONENTS SUGGESTED VALUE PURPOSE
LARGER THAN
SUGGESTED
R1 (*) 22k INPUT RESISTANCE INCREASE INPUT
IMPEDANCE
R2 680
CLOSED LOOP GAIN
DECREASE OF GAIN INCREASE OF GAIN
SMALLER THAN
SUGGESTED
DECREASE INPUT
IMPEDANCE
SET TO 30dB (**)
R3 (*) 22k INCREASE OF GAIN DECREASE OF GAIN
R4 22k ST-BY TIME
CONSTANT
LARGER ST-BY
ON/OFF TIME
SMALLER ST-BY
ON/OFF TIME;
POP NOISE
R5 10k MUTE TIME
CONSTANT
C1 0.47µF INPUT DC
DECOUPLING
LARGER MUTE
ON/OFF TIME
SMALLER MUTE
ON/OFF TIME HIGHER LOW
FREQUENCY
CUTOFF
C2 22µF FEEDBACK DC
DECOUPLING
HIGHER LOW
FREQUENCY
CUTOFF
C3 10µF MUTE TIME
CONSTANT
C4 10µF ST-BY TIME
CONSTANT
LARGER MUTE
ON/OFF TIME
LARGER ST-BY
ON/OFF TIME
SMALLER MUTE
ON/OFF TIME
SMALLER ST-BY
ON/OFF TIME;
POP NOISE
C5 22µFXN (***) BOOTSTRAPPING SIGNAL
C6, C8 1000µF SUPPLY VOLTAGE
C7, C9 0.1µF SUPPLY VOLTAGE
(*) R1 = R3 for pop optimization (**) Closed Loop Gain has to be 26dB (***) Multiply this value for the number ofmodular part connected
Slave function: pin 4 (Ref to pin 8 -VS)
-V
+3V
S
-V
+1V
S
-V
S
MASTER
UNDEFINED
SLAVE
D98AU821
DEGRADATION AT LOW FREQUENCY
BYPASS
DANGER OF
BYPASS
OSCILLATION
Note:
If in the application, the speakers are connected via long wires, it is a good rule to add between the output and GND, a BoucherotCell, in order to avoid dangerous spurious oscillations when the speakersterminalare shorted.
The suggested Boucherot Resistor is 3.9Ω/2W and the capacitor is 1µF.
5/11
TDA7296S
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 phoenomenon. It limits the safe operating area (SOA) of the power devices, and, as a con­sequence, the maximum attainable output power, especiallyin presenceof highlyreactive loads.
Moreover, full exploitation of the SOA translates into a substantial increase in circuit and layout complexity due to the need of sophisticated pro­tectioncircuits.
To overcome these substantial drawbacks, the use of power MOS devices, which are immune fromsecondary breakdown is highlydesirable.
1) Output Stage
The main design task in developping a power op­erational amplifier, independently of the technol­ogyused, is that of realizationof theoutput stage.
The solution shown as a principle shematic by Fig3 represents the DMOS unity - gain output bufferof the TDA7296S.
This large-signal, high-power buffer must be ca­pable of handling extremely high current and volt­age levels while maintaining acceptably low har­monic distortion and good behaviour over frequency response; moreover, an accurate con­trol of quiescentcurrent is required.
A local linearizing feedback, provided by differen­tial amplifier A, is used to fullfil the above require­ments, allowing a simple and effective quiescent currentsetting.
Proper biasing of the power output transistors alone is however not enoughto guaranteethe ab­sence of crossoverdistortion.
While a linearization of the DC transfer charac­teristic of the stage is obtained, the dynamic be­haviour of the system 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 feedbackpath enclosing the outputstage itself.
2) Protections
In designing a power IC, particularattention must be reserved to the circuits devoted to protection of the device from short circuit or overload condi­tions.
Due to the absence of the 2nd breakdown phe­nomenon, the SOA of the power DMOS transis­tors 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 imple­mented in this device combines a conventional SOA protection circuit with a novel local tempera­ture sensing technique which ” dynamically” con­trols the maximum dissipation.
In addition to the overload protection described
Figure3: PrincipleSchematicof a DMOSunity-gain buffer.
6/11
Figure4: Turn ON/OFFSuggested Sequence
+Vs
(V)
+40
-40
-Vs V
IN
(mV)
V
ST-BY
PIN
(V)
5V
#9
TDA7296S
#10
5V
OFF
ST-BY
PLAY
MUTE MUTE
V
MUTE
PIN
(mA)
V
(V)
IQ
OUT (V)
above, the device features a thermal shutdown circuit which initially puts the device into a muting state (@ Tj = 150 Tj = 160
o
C).
o
C) and then into stand-by (@
Full protection against electrostaticdischarges on everypin is included.
Figure5: SingleSignalST-BY/MUTEControl
Circuit
MUTE STBY
MUTE/
ST-BY
20K
10K 30K
1N4148
10µF10µF
D93AU014
3) Other Features
The device is provided with both stand-by and mute functions, independently driven by two CMOSlogic compatibleinput pins.
The circuits dedicated to the switchingon and off of the amplifier have been carefully optimized to
ST-BY OFF
D98AU817
avoid any kind of uncontrolledaudibletransient at the output. The sequence that we recommend during the ON/OFFtransientsis shown by Figure4. The application of figure 5 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 supply voltage.
APPLICATION INFORMATION BRIDGEAPPLICATION
Another application suggestion is the BRIDGE configuration,where two TDA7296S are used. 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.
Themain advantagesoffered by this solution are:
- High power performanceswith limited supply voltagelevel.
- Considerablyhigh output powereven with high load values (i.e. 16 Ohm).
With Rl= 8 Ohm, Vs = ±23V the maximum output powerobtainable is 120W (Music Power)
7/11
TDA7296S
APPLICATION NOTE: (ref. fig. 7) ModularApplication (more Devices in Parallel)
The use of the modular application lets very high power be delivered to very low impedance loads. The modular application implies one device to act as a masterand the others as slaves.
The slave power stages are driven by the master device and work in parallel all together, while the input and the gain stages of the slave device are disabled, the figure below shows the connections required to configure two devices to work to­gether.
The master chip connections are the same as the normal single ones.
The outputs can be connected together with-
out the need of any ballast resistance.
Figure6: ModularApplication Circuit
C7 100nF C6 1000µF
IN+
SGND
MUTE
STBY
IN- 2
C4 10µF
R3 22K
3
4
10
9
-
+
MUTE
STBY
1 STBY-GND
C7 100nF C6 1000µF
MASTER
VMUTE
VSTBY
C2
22µF
R1 22K
R5 10K
R4 22K
R2
680
C1 470nF
C3 10µF
The slave SGND pin must be tied to the nega­tivesupply.
The slave ST-BY pin must be connected to ST-BYpin.
The bootstrap lines must be connected to­gether and the bootstrap capacitor must be in­creased: for N devices the boostrap capacitor mustbe 22µF times N.
The slave Mute and IN-pins must be grounded.
THE BOOTSTRAP CAPACITOR
For compatibility purpose with the previous de­vices of the family, the boostrapcapacitor can be connectedboth betweenthe bootstrap pin (6) and the output pin (14) or between the boostrap pin (6) and the bootstraploader pin (12).
+Vs
BUFFER
DRIVER
11
713
THERMAL
SHUTDOWN
-Vs -PWVs
C9 100nF C8 1000µF
PROTECTION
158
-Vs +Vs
+PWVs+Vs
OUT
14
C10
C5
47µF
100nF
R7 2
S/C
12
6 5
BOOT LOADER
BOOTSTRAP CLIP DET
8/11
SLAVE
IN+ 3
SGND
MUTE
STBY
IN- 2
BUFFER
DRIVER
11
713
-
+
4
10
MUTE
9
STBY
1 STBY-GND
THERMAL
SHUTDOWN
-Vs -PWVs
C9 100nF C8 1000µF
PROTECTION
158
-Vs
+PWVs+Vs
OUT
14
BOOT
12
LOADER
6
BOOTSTRAP
S/C
5
D97AU808C
TDA7296S
Figure7a: Modular Application P.C.Board and ComponentLayout (scale 1:1) (Component SIDE)
Figure7b: ModularApplication P.C. Board and ComponentLayout (scale1:1) (SolderSIDE)
9/11
TDA7296S
DIM.
Dia1 3.65 3.85 0.144 0.152
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 1.02 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
mm inch
OUTLINE AND
MECHANICALDATA
Multiwatt15 V
10/11
TDA7296S
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