SGS Thomson Microelectronics TDA7298 Datasheet
28W Hi-Fi AUDIO POWER AMPLIFIER
SUPPLYVOLTAGERANGEUP TO ±22V
SPLIT SUPPLY OPERATION
HIGHOUTPUT POWER
(UP TO 28W MUSICPOWER)
LOW DISTORTION
MUTE/STAND-BY FUNCTION
NO SWITCH ON/OFF NOISE
AC SHORT CIRCUIT PROTECTION
THERMALSHUTDOWN
ESDPROTECTION
DESCRIPTION
The TDA7298 is a monolithic integrated circuit in
Heptawatt package, intended for use as audio
class AB amplifier in TV or Hi-Fi field application.
Thanks to the wide voltage range and to the high
out current capability it’s able to supply the high-
TEST AND APPLICATION CIRCUIT
TDA7298
WITH MUTE / STAND-BY
Heptawatt
ORDERING NUMBER: TDA7298
est power into both 4Ωand 8Ωloads even in
presenceof poorsupply regulation.
The built in Muting/Stand-by function simplifies
the remote operationsavoiding also switching onoff noises.
May 1997
1/11
TDA7298
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
I
O
P
tot
T
op
T
stg,Tj
PIN CONNECTION (Topview)
DC Supply Voltage ±22 V
S
Output PeakCurrent (internally limited) 4 A
Power DissipationT
=70°C30W
case
Operating Temperature Range 0 to +70 °C
Storage and Junction Temperature -40 to +150 °C
BLOCK DIAGRAM
2/11
TDA7298
THERMAL DATA
Symbol Description Value Unit
R
th j-case
Thermal Resistance Junction-case Max 2.5
C/W
°
ELECTRICAL CHARACTERISTICS (Refer to the test circuit, GV= 32dB; VS+ 18V; f = 1KHz; T
25°C, unlessotherwisespecified.)
Symbol Parameter Test Condition Min. Typ. Max. Unit
V
S
I
q
I
b
V
OS
I
OS
P
O
P
O
Supply Range +6 +22 V
Total Quiescent Current VS= +22V 20 40 70 mA
Input Bias Current +0.5
Input Offset Voltage +15 mV
Input Offset Current +200 nA
Music Output Power
IEC268-3 Rules (*)
VS= + 20, RL=8Ω,
d = 10%, t = 1s
28 W
Output Power(continuous RMS) d = 10%
RL = 4Ω V
R
=8
L
Ω
= +14V
S
20
20
24
24
d=1%
R
d Total Harmonic Distortion R
=4Ω VS= +14V
L
R
=8Ω
L
=4ΩVS= +14V
L
P
= 0.1 to 10W;
O
f = 100Hz to 15KHz
=8Ω
R
L
P
= 0.1 to 10W;
O
f = 100Hz to 15KHz
17
17
0.1
0.1
0.7
0.5
SR Slew Rate 3 5 V/µs
G
V
e
N
R
SVR Supply Voltage Rejection f = 100Hz, V
T
S
Open Loop Voltage Gain 80 dB
Total Input Noise A Curve
f = 20Hz to 20KHz
Input Resistance 500 KΩ
i
ripple =1VRMS 40 50 dB
2
310
Thermal Shutdown 145
MUTE/STAND-BY FUNCTION (Ref. –VS)
=
amb
A
µ
W
W
W
W
%
%
µV
V
µ
C
°
VT
ST-BY
VT
PLAY
I
q ST-BY
ATT
ST-BY
I
pin3
Note (*):
MUSIC POWER CONCEPT
MUSIC POWER is ( according tothe IECclauses n.268-3of Jan 83) the maximalpowerwhichtheamplifier is capable of producingacrossthe
rated load resistance (regardless of non linearity) 1 sec after the application of a sinusoidalinput signal of frequency 1KHz.
According to this definition our method of measurement comprises the following steps:
1) Set the voltage supply at the maximumoperatingvalue -10%
2) Apply a input signal in the formofa 1KHz tone burst of 1 sec duration; the repetition period of the signal pulses is > 60 sec
3) The output voltage is measured 1 sec from the start of the pulse
4) Increase the input voltage until the outputsignal show a THD = 10%
5) The music power is thenV
The target of this method isto avoidexcessive dissipation in theamplifier.
Stand-by - Threshold 1 1.8 V
Play Threshold 2.7 4 V
Quiescent Current @ Stand-by V
= 0.5V 1 3 mA
pin 3
Stand-by Attenuation 70 90 dB
Pin 3 Current @ Stand-by –1 +10
2
/R1,where V
out
istheoutputvoltage measured in the condition of point 4) and R1 is the rated load impedance
out
µ
A
3/11
TDA7298
APPLICATIONS SUGGESTIONS (See Testand ApplicationCircuit)
The recommended values of the externalcomponents are those shown on the application circuit. Different values can be used;the followingtable can help the designer.
Comp. Value Purpose Larger Than Smaller Than
Ω
R1 22K
R2 560Ω Closed LoopGain set to
R3 22K
R4 22K
R5 22K
R6 4.7Ω Frequency Stability Danger of oscillations Danger of oscillations
C1 1µF Input DC Decoupling Higher Low-frequency
C2 10µF Feedback DC Decoupling Higher Low-frequency
C3 10µF Stand-by Time Constant
C4 0.100µF Frequency Stability Danger of Oscillations
C5, C6 1000µF Supply Voltage Bypass
(*) R1 = R3= R4 for POP optimization
(**) Closed Loop Gain hasto be ≥ 30dB
(*) Input Impedance Increase of Input
(*) Increase of Gain Decrease of Gain
Ω
Ω
(*) Input Impedance @ Mute
Ω
32dB (**)
Stand-by Time Constant
Impedance
Decrease of Gain Increase of Gain
Decrease of Input
Impedance
cut-off
cut-off
TYPICALCHARACTERISTICS
Figure 1: OutputPower vs. Supply Voltage
4/11
Figure2: Distortionvs. Output Power
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