TDA8579T
Dual common-mode rejection differential line receiver
Rev. 4 — 23 September 2013
Product data sheet
1. General description
The TDA8579T is a two channel differential amplifier with 0 dB gain and low distortion.
The device has been primarily developed for car radio applications where long
connections between signal sources and amplifiers (or boosters) are necessary and
where ground noise has to be eliminated. The device is intended to be used to receive line
inputs in audio applications that require a high level of common-mode rejection. The
device is contained in an 8-pin Small Outline (SO) package.
2. Features and benefits
Excellent common-mode rejection, up to high frequencies
Elimination of source resistance dependency in the common-mode rejection
Few external components
High supply voltage ripple rejection
Low noise
Low distortion
All pins protected against electrostatic discharge
AC and DC short-circuit safe to ground and V
CC
Fast DC settling
3. Quick reference data
Table 1.
Symbol
V
CC
I
CC
G
V
SVRR
V
no
|Z
i
|
CMRR
Quick reference data
Parameter
supply voltage
supply current
voltage gain
supply voltage ripple rejection
noise output voltage
input impedance
common-mode rejection ratio
R
s
= 0
V
CC
= 8.5 V
Conditions
Min
5.0
-
0.5
55
-
100
-
Typ
8.5
11
0
60
3.7
240
80
Max
18
14
+0.5
-
5.0
-
-
Unit
V
mA
dB
dB
V
k
dB
NXP Semiconductors
TDA8579T
Dual common-mode rejection differential line receiver
4. Ordering information
Table 2.
Ordering information
Package
Name
TDA8579T
SO8
Description
plastic small outline package; 8 leads; body width 3.9 mm
Version
SOT96-1
Type number
5. Block diagram
V
CC
8
INL+
1
V
CC
7
OUTL
IN-
2
TDA8579T
4
SVRR
INR+
3
5
GND
6
OUTR
aaa-008045
Fig 1.
Block diagram
6. Pinning information
6.1 Pinning
INL+
IN-
INR+
SVRR
1
2
3
4
aaa-008040
8
VCC
OUTL
OUTR
GND
TDA8579T
7
6
5
Fig 2.
Pin configuration
TDA8579T
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
Product data sheet
Rev. 4 — 23 September 2013
2 of 16
NXP Semiconductors
TDA8579T
Dual common-mode rejection differential line receiver
6.2 Pin description
Table 3.
Symbol
INL+
IN
INR+
SVRR
GND
OUTR
OUTL
V
cc
Pin description
Pin
1
2
3
4
5
6
7
8
Description
positive input left
common negative input
positive input right
half supply voltage
ground
output right
output left
supply voltage
7. Functional description
The TDA8579T contains two identical differential amplifiers with a voltage gain of 0 dB.
The device is intended to receive line input signals for audio applications. The TDA8579T
has a very high level of common-mode rejection and thus eliminates ground noise. The
common-mode rejection remains constant up to high frequencies (the amplifier gain is
fixed at 0 dB). The inputs have a high input impedance. The output stage is a class AB
stage with a low output impedance. For a large common-mode rejection, also at low
frequencies, an electrolytic capacitor connected to the negative input is advised. Because
the input impedance is relatively high, this results in a large settling time of the DC input
voltage. Therefore a quick-charge circuit is included to charge the input capacitor within
0.2 seconds.
All input and output pins are protected against high electrostatic discharge conditions
(4000 V, 150 pF, 150
).
TDA8579T
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
Product data sheet
Rev. 4 — 23 September 2013
3 of 16
NXP Semiconductors
TDA8579T
Dual common-mode rejection differential line receiver
8. Limiting values
Table 4.
Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). All voltages and currents
are referenced to GND unless otherwise specified.
Symbol Parameter
V
CC
I
ORM
V
sc
T
stg
T
amb
T
j
supply voltage
repetitive peak output current
AC and DC short-circuit safe voltage
storage temperature
ambient temperature
maximum junction temperature
Conditions
Min
-
-
-
55
40
-
Max
18
40
18
+150
+85
150
Unit
V
mA
V
C
C
C
9. Thermal characteristics
Table 5.
Thermal characteristics
According to IEC 60747-1.
Symbol Parameter
R
th(j-a)
thermal resistance from junction to ambient
Conditions
in free air
Value
160
Unit
K/W
TDA8579T
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
Product data sheet
Rev. 4 — 23 September 2013
4 of 16
NXP Semiconductors
TDA8579T
Dual common-mode rejection differential line receiver
10. Characteristics
Table 6.
Electrical characteristics
V
CC
= 8.5 V; T
amb
= 25
C; test circuit (see
Figure 3);
unless otherwise specified.
Symbol Parameter
V
CC
I
CC
V
O
t
set
G
v
cs
|G
v
|
f
L
f
H
|Z
i
|
|Z
o
|
V
i(max)
V
no
supply voltage
supply current
output voltage
DC input voltage settling time
voltage gain
channel separation
channel unbalance
LOW frequency roll-off
HIGH frequency roll-off
input impedance
output impedance
maximum input voltage
noise output voltage
THD = 1 %
R
s
= 0
[3]
[1]
Conditions
Min
5.0
-
-
-
0.5
Typ
8.5
11
4.3
0.2
0
80
-
-
-
240
-
2.0
3.7
-
70
80
65
60
0.02
-
-
Max
18
14
-
-
+0.5
-
0.5
-
-
-
10
-
5.0
1.0
-
-
-
-
-
0.1
1
Unit
V
mA
V
s
dB
dB
dB
Hz
kHz
k
V
V
V
dB
dB
dB
dB
%
%
%
R
s
= 5 k
1
dB
1
dB
[2]
70
-
20
20
100
-
-
-
-
V
CM(rms)
common-mode input voltage
(RMS value)
CMRR
SVRR
THD
common-mode rejection ratio
supply voltage ripple rejection
total harmonic distortion
V
i
= 1 V;
V
i
= 1 V;
f = 20 Hz to 20 kHz
THD
max
total harmonic distortion at
maximum output current
[1]
[2]
[3]
[4]
R
s
= 5 k
R
s
= 0
[4]
[5]
[6]
66
-
55
-
-
-
-
V
i
= 1 V; R
L
= 150
The DC output voltage with respect to ground is approximately 0.5V
CC
.
The input coupling capacitors set the frequency response externally.
The noise output voltage is measured in a bandwidth of 20 Hz to 20 kHz (unweighted).
The common-mode rejection ratio is measured at the output with a voltage source 1 V (RMS) in
accordance with the test circuit (see
Figure 3).
V
INL
and V
INR
are short-circuited. Frequencies are between
100 Hz and 100 kHz.
The ripple rejection is measured at the output, with R
s
= 2 k, f = 1 kHz and a ripple amplitude of 2 V (p-p).
The ripple rejection is measured at the output. R
s
= 0
to 2 k, f = 100 Hz to 20 kHz and a maximum
ripple amplitude of 2 V (p-p).
[5]
[6]
TDA8579T
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
Product data sheet
Rev. 4 — 23 September 2013
5 of 16
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