Document Outline
- FEATURES
- GENERAL DESCRIPTION
- QUICK REFERENCE DATA
- ORDERING INFORMATION
- BLOCK DIAGRAM
- PINNING
- FUNCTIONAL DESCRIPTION
- System description
- Power on
- LIMITING VALUES
- THERMAL CHARACTERISTICS
- QUALITY SPECIFICATION
- DC CHARACTERISTICS
- AC CHARACTERISTICS
- APPLICATION INFORMATION
- PACKAGE OUTLINES
- SOLDERING
- DEFINITIONS
- LIFE SUPPORT APPLICATIONS
DATA SHEET
Preliminary specification
File under Integrated Circuits, IC01
1996 Jul 29
INTEGRATED CIRCUITS
TDA8575
Ground noise isolation amplifier
1996 Jul 29
2
Philips Semiconductors
Preliminary specification
Ground noise isolation amplifier
TDA8575
FEATURES
High common mode rejection up to high frequencies
Reduced dependency of common mode rejection on
source resistance
Low distortion
Low noise
AC and DC short-circuit safe
Few external components
ESD protected on all pins.
GENERAL DESCRIPTION
The TDA8575(T) is a two channel amplifier with differential
input and single-ended output for use in car audio
applications. The differential amplifier has a gain of 0 dB,
a low distortion and a high common mode rejection. The
TDA8575T comes in a 16 pin SO package and TDA8575
comes in a 16 pin DIP package.
The TDA8575(T) is developed for those car audio
applications where long connections between signal
sources and amplifiers (or boosters) are necessary and
ground noise has to be eliminated.
QUICK REFERENCE DATA
ORDERING INFORMATION
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
V
CC
supply voltage
5
8.5
18
V
I
CC
supply current
V
CC
= 8.5 V
-
12.6
15
mA
G
v
voltage gain
-
0.5
0
+0.5
dB
V
o(rms)(max)
maximum output voltage (RMS value)
THD = 0.1%
-
1.7
-
V
SVRR
supply voltage ripple rejection
55
60
-
dB
CMRR
common mode rejection ratio
R
s
= 0
-
80
-
dB
THD
total harmonic distortion
V
o(rms)
= 1 V; f = 1 kHz
-
0.005
-
%
V
no
noise output voltage
-
3.7
5
V
Z
i
input impedance
-
108
-
k
Z
o
output impedance
-
-
10
TYPE
NUMBER
PACKAGE
NAME
DESCRIPTION
VERSION
TDA8575T
SO16
plastic small outline package; 16 leads; body width 3.9 mm
SOT109-1
TDA8575
DIP16
plastic dual in-line package; 16 leads (300 mil); long body
SOT38-1
1996 Jul 29
3
Philips Semiconductors
Preliminary specification
Ground noise isolation amplifier
TDA8575
BLOCK DIAGRAM
Fig.1 Block diagram.
handbook, full pagewidth
MGE829
360 k
16
0.5(VCC
-
0.7)
+
0.7
0.5(VCC
-
0.7)
+
0.7
VCC
VCC
9
GND
8
SVRR
12
OUTL
11
OUTR
0.68(VCC
-
0.7)
+
0.7
0.68(VCC
-
0.7)
+
0.7
REFERENCE
360 k
108
k
108
k
TDA8575(T)
1
5
6
INR
+
INR
-
7
INL
+
INL
-
V I
I V
I V
V I
1996 Jul 29
4
Philips Semiconductors
Preliminary specification
Ground noise isolation amplifier
TDA8575
PINNING
SYMBOL
PIN
DESCRIPTION
INL+
1
positive input left
n.c.
2
not connected
n.c.
3
not connected
n.c.
4
not connected
INL
-
5
negative input left
INR
-
6
negative input right
INR+
7
positive input right
SVRR
8
supply voltage ripple rejection
GND
9
ground
n.c.
10
not connected
OUTR
11
output voltage right channel
OUTL
12
output voltage left channel
n.c.
13
not connected
n.c.
14
not connected
n.c.
15
not connected
V
CC
16
supply voltage
Fig.2 Pin configuration TDA8575T.
handbook, halfpage
TDA8575T
MGE828
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
INL
+
n.c.
n.c.
n.c.
INL
-
INR
-
INR
+
SVRR
GND
n.c.
OUTR
OUTL
n.c.
n.c.
n.c.
VCC
handbook, halfpage
TDA8575
MGE827
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
INL
+
n.c.
n.c.
n.c.
INL
-
INR
-
INR
+
SVRR
GND
n.c.
OUTR
OUTL
n.c.
n.c.
n.c.
VCC
Fig.3 Pin configuration TDA8575.
1996 Jul 29
5
Philips Semiconductors
Preliminary specification
Ground noise isolation amplifier
TDA8575
FUNCTIONAL DESCRIPTION
System description
To enable a high common mode rejection a new system
setup is used. The voltage to current converter, referred to
as V
I in the block diagram of Fig.1, replaces the
resistors that can be seen in the conventional system
solution.
Both systems are shown in Figs 4 and 5. In the
conventional system the common mode rejection is limited
by the matching properties of the resistors resulting in a
CMRR of 60 dB maximum. Using the new system setup a
CMRR of 80 dB is achieved.
Power on
In Fig.6 the preferred input capacitor values are shown.
If the capacitor C2 = 22
F connected to the IN- inputs had
to be charged by the 0.5V
cc
voltage source a charge time
of
would be required.
5
5
360 k
2
-------------------
22
F
20s
=
=
This is inconvenient for most applications and therefore
the TDA8575(T) is equipped with a quick charge circuit.
On power-on the quick charge circuit charges the
capacitor C2 connected to the IN- pins. The quick charge
circuit consists of a voltage buffer and a control circuit
(referred to as `reference and power check' in Fig.6) that
monitors the supply voltage V
CC
. If the supply voltage rises
more than
2 V the voltage buffer is switched on.
After charging C2 the voltage buffer is switched off.
The charge time of C2 will equal the charge time of C4, the
SVRR capacitor.
Fig.4 Conventional system.
handbook, halfpage
MGE830
Vo
Vi
0.5 VCC
Fig.5 New system using V
I converters.
handbook, halfpage
0.5 VCC
Vo
Vi
V I
I V
MGE831
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