TDA7256
30W BRIDGE CAR RADIO AMPLIFIER
NO AUDIBLE POP DURING MUTE AND
STANDBY OPERATIONS
MUTING TTL COMPATIBLE
VERY LOW STANDBY CONSUMPTION
PROGRAMMABLE TURN ON DELAY
DIFFERENTIAL INPUT
SHORT CIRCUIT PROTECTIONS:
RL SHORT - OUT TO GROUND - OUT TO V
S
OTHER PROTECTIONS:
- Load dump voltage surge
- Loudspeaker DC current
- Very inductive load
- Overrating temperature
- Open ground
DESCRIPTION
The TDA7256 is a class AB fully protected bridge
power amplifier, designed for car radio applica-
tions. The high current capability allows to drive
low impedance loads (up to 2
). The differential
inputs availability makes it particularly suitable for
boosters and active loudspeakers applications.
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
October 1998
BLOCK DIAGRAM
MULTIWATT11
ORDERING NUMBER: TDA7256
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PIN CONNECTION (Top view)
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Test Conditions
Unit
V
S
Operating Supply Voltage
18
V
V
S
DC Supply Voltage
28
V
V
S
Peak Supply Voltage (for 50ms)
40
V
I
o
Output Peak Current (non repetiitive t = 0.1ms)
internally limited
I
o
Output Peak Current Repetitive f > 10Hz
5.5
A
P
tot
Power Dissipation (Tcase = 85
C)
36
W
T
stg,
T
J
Storage and Junction Temperature Range
-40 to +150
C
THERMAL DATA
Symbol
Description
Value
Unit
R
th j-case
Thermal Resistance Junction-case
Max
1.8
C/W
TDA7256
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ELECTRICAL CHARACTERISTICS (V
S
= 14.4V, R
L
= 4
, f = 1KHz; T
amb
= 25
C, unless otherwise
specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
S
Supply Voltage
8
18
V
I
q
Quiescent Drain Current
80
150
mA
R
i
Input Resistance
50
K
CMR
Common Mode Rejection
f = 1KHz, V
in
= 100mV
60
dB
V
OS
Output Offset Voltage
150
mV
P
o
Output Power
d = 10%
R
L
= 4
R
L
= 3.2
R
L
= 2
18
22
26
30
W
W
W
d
Distortion
P
o
= 0.1W to 13W
0.05
0.5
%
G
V
Voltage Gain (CL)
36
dB
e
N
Total Input Noise Voltage
R
g
= 10K
, B = 22Hz to 22KHz
3
10
V
SVR
Supply Voltage Rejection
R
g
= 10K
, V
r
= 1Vrms,
f = 300Hz
45
60
dB
Muting Attenuation
V
ref
= 1Vrms,
f = 100Hz to 10KHz
60
dB
Muting-in Threshold Voltage
Pin 1
2.4
V
Muting-out Threshold Voltage
Pin 1
0.8
V
Stand-by Attenuation
Vref = 1Vrms
60
dB
Stand-by Current Consumption
100
A
T
SD
Thermal Shut-down Junction
Temperature
145
C
Figure 1: Test and Application Circuit
TDA7256
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Figure 4: Output Power vs. Supply Voltage
Figure 3: Drain Current vs. Supply Voltage
Figure 2: P.C. and Layout of the fig.1 (1:1 scale)
TDA7256
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Figure 10: Distortion vs. Frequency
Figure 5: Output Power vs. Supply Voltage
Figure 6: Output Power vs. Supply Voltage
Figure 8: Distortion vs. Output Power
Figure 9: Distortion vs. Output Power
Figure 7: Distortion vs. Output Power
TDA7256
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