TECHNICAL DATA
5 W MONO BTL AUDIO AMPLIFIER
WITH DC VOLUME CONTROL
ILA7056B
The ILA7056B is a mono Bridge-Tied Load (BTL) output amplifier with DC
volume control. It is designed for use in TV and monitors, but is also suitable for
battery-fed portable recorders and radios. The device is contained in a 9-pin
medium power package.
ORDERING INFORMATION
Plastic SIL-9MPF
(SOT110-1)
T
A
= -40
C to 125 C
A Missing Current Limiter (MCL) is built in. The MCL circuit is activated when
the difference in current between the output terminal of each amplifier exceeds
100 mA (300 mA typ.). This level of 100 mA allows for headphone applications
(single-ended).
FEATURES
DC volume control
Few external components
Mute mode
Thermal protection
Short-circuit proof
No switch-on and switch-off clicks
Good overall stability
Low power consumption
Low HF radiation
ESD protected on all pins
Figure 1. Pin connection
Figure 2. Simplified Block Diagram
1
ILA7056B
MAXIMUM RATINGS
SYMBOL PARAMETER CONDITIONS
MIN MAX
UNIT
V
P
supply voltage
-
18
V
V
3, 5
input voltage pins 3 and 5
-
5
V
I
ORM
repetitive peak output current
-
1.25
A
I
OSM
non-repetitive peak output current
-
1.5
A
P
tot
total power dissipation
T
case
< 60
C -
9
W
T
amb
operating ambient temperature
-40
+85
C
T
stg
storage temperature
-55
+150
C
T
vj
virtual junction temperature
-
+150
C
T
sc
short-circuit time
-
1
h
ELECTRICAL CHARACTERISTICS
V
P
= 12 V; V
DC
= 1.4 V; f = 1 kHz; R
L
= 16
; T
amb
= 25
C; unless otherwise specified (see Fig.13).
SYMBOL PARAMETER
CONDITIONS MIN
TYP
MAX UNIT
Supply
V
P
positive supply voltage
4.5
- 18
V
I
q(tot)
total quiescent current
note 1; R
L
=
- 9.2
13
mA
Maximum gain (V5 1.4 V)
P
O
output power
THD = 10%; R
L
= 16 3 3.5
- W
THD = 10%; R
L
= 8
- 5
- W
THD total
harmonic
distortion
P
O
= 0.5 W
- 0.3
1 %
G
v(max)
maximum total voltage gain
39.5
40.5
41.5
dB
V
I
input signal handling (RMS value)
G
v(max)
= 0 dB; THD
<1%
1.0
-
- V
V
no
noise output voltage (RMS value)
note 2; f = 500 kHz
- 210 - V
B bandwidth
at
-1dB
- 0.02
to
300
- kHz
SVRR
supply voltage ripple rejection
note 3
34
38
- dB
V
O
DC output offset voltage
V
8
- V
6
- 0
200
mV
Z
I
input impedance (pin 3)
15
20
25
kHz
Mute position
V
O
output voltage in mute position
note 4; V
5
= 0.4 V
30 mV
V
I
= 1.0 V
- 30
40
V
DC volume control; note 5
gain
control
68
73.5 dB
I
5
control current
V
5
= 0 V
20
25
30
A
Notes
1. With a load connected to the outputs the quiescent current will increase, the maximum value of this increase being
equal to the DC output offset voltage divided by R
L
.
2. The noise output voltage (RMS value) at f = 500 kHz is measured with R
S
= 0 and B = 5 kHz.
3. The ripple rejection is measured with R
S
= 0 and f = 100 Hz to 10 kHz. The ripple voltage V
R
of 200 mV (RMS
value) is applied to the positive supply rail.
4. The noise output voltage (RMS value) is measured with R
S
= 5 k unweighted.
5. The DC volume control can be configured in several ways. Two possible circuits are shown in Figs 14 and 15. The
circuits at the volume control pin will influence the switch-on and switch-off behaviour and the maximum voltage
gain.
2
ILA7056B
FUNCTIONAL DESCRIPTION
The ILA7056B is a mono BTL output amplifier with DC volume control, designed for use in TV and monitor but is
also suitable for battery-fed portable recorders and radios.
In conventional DC volume circuits the control or input stage is AC coupled to the output stage via external capacitors
to keep the offset voltage low. In the ILA7056B the DC volume control stage is integrated into the input stage so that no
coupling capacitors are required. With this configuration, a low offset voltage is still maintained and the minimum
supply voltage remains low.
The BTL principle offers the following advantages:
Lower peak value of the supply current
The frequency of the ripple on the supply voltage is twice the signal frequency.
Consequently, a reduced power supply with smaller capacitors can be used which results in cost reductions. For
portable applications there is a trend to decrease the supply voltage, resulting in a reduction of output power at
conventional output stages. Using the BTL principle increases the output power.
The maximum gain of the amplifier is fixed at 40.5 dB. The DC volume control stage has a logarithmic control
characteristic. Therefore, the total gain can be controlled from 40.5 dB to -33 dB. If the DC volume control voltage falls
below 0.4 V, the device will switch to the mute mode.
The amplifier is short-circuit proof to ground, V
P
and
across the load. Also a thermal protection circuit is implemented. If the crystal temperature rises above +150
o
C the gain
will be reduced, thereby reducing the output power. Special attention is given to switch-on and switch-off clicks, low
HF radiation and a good overall stability.
Power dissipation
Assume V
P
= 12 V; R
L
= 16
.
The maximum sine wave dissipation is = 1.8 W.
The R
th vj-a
of the package is 55 K/W.
Therefore T
amb (max)
= 150 - 55 x1.8 = 51
o
C.
Figure 3. Gain control as a function of DC volume control.
Figure 4. Noise output voltage as a function of DC volume
control.
3
ILA7056B
Figure 5.
Control current as a function of DC volume control.
Figure 6.
Quiescent current versus supply voltage.
Figure 7. Total harmonic distortion versus output power.
(1)
R
L
16
(2)
R
L
= 8
(3)
R
L
= 4 , V
P
= 12 V
Figure 8.
Total harmonic distortion versus frequency.
P
O
= 0.1 W.
(1)
G
v(max)
= 40 dB.
(2)
G
v(max)
= 30 dB.
4
ILA7056B
Figure 9. Output power versus supply voltage.
Measured at a THD of 10%. The maximum output power is limited
by the maximum power dissipation and the maximum available
output current.
(1)
R
L
= 4
(2)
R
L
= 8
(3)
R
L
= 16
Figure 10. Total worst case power dissipation versus supply
voltage.
(1)
R
L
= 4
(2)
R
L
= 8
(3)
R
L
= 16
Fig.11 Supply voltage ripple rejection versus frequency.
Fig.12 Input signal handling.
5
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