|
OP179 Datasheet, PDF (10/16 Pages) Analog Devices – Rail-to-Rail High Output Current Operational Amplifiers | |||
|
◁ |
OP179/OP279
TO TELEPHONE
LINE
1:1
R3
55â
ZO
110â
T1
6.2V
6.2V
R4
55â
P1
TX GAIN
ADJUST
R2
9.09kâ
2kâ
2
1
R5
10kâ
A1 3
R1
10kâ
C1
0.1â®F
TRANSMIT
TXA
R6
10kâ 7
6
A2 5
+5V DC
10â®F
R7
10kâ
R8
10kâ
R9
10kâ
R10
10kâ
R11
10kâ
2
1
3 A3
R12
A1, A2 = 1/2 OP279 10kâ
A3, A4 = 1/2 OP279
R13
10kâ
P2
RX GAIN
R14 ADJUST
9.09kâ
RECEIVE
RXA
6
2kâ C2
5 A4
7
0.1â®F
Figure 31. A Single Supply Direct Access Arrangement for
Modems
A Single Supply, Remote Strain Gage Signal Conditioner
The circuit in Figure 32 illustrates a way by which the OP179/
OP279 can be used in a +12 V single supply, 350 ⦠strain gage
signal conditioning circuit. In this circuit, the OP179/OP279
serves two functions: (1) By servoing the output of the REF43âs
+2.5 V output across R1, it provides a 20 mA drive to the 350 â¦
strain gage. In this way, small changes in the strain gage pro-
duce large differential output voltages across the AMP04âs in-
puts. (2) To maximize the circuitâs dynamic range, the other
half of the OP179/OP279 is configured as a supply-splitter
connected to the AMP04âs REF terminal. Thus, tension or
compression in the application can be measured by the circuit.
+12V
2
8
1
3 +2.5V 6
REF43
0.1â®F
F+
A1 2
4
4
20mA DRIVE
S+
Sâ
100-ft TWISTED PAIR
BELDEN TYPE 9502
Fâ
350â
STRAIN GAGE
+12V R4 C2
1kâ 0.1â®F
7
CX
R1
3
1
8
AMP04 6
2
45
VO
80mV/â
124â
0.1%, LOW TCR
VO
COMMON
+12V
R2
10kâ
6
5 A2
7 +6V
C1
10â®F
R3
10kâ
A1, A2 = 1/2 OP279
The AMP04 is configured for a gain of 100, producing a circuit
sensitivity of 80 mV/â¦. Capacitor C2 is used across the AMP04âs
Pins 8 and 6 to provide a 16-Hz noise filter. If additional noise
filtering is required, an optional capacitor, CX, can be used
across the AMP04âs input to provide differential-mode noise
rejection.
A Single Supply, Balanced Line Driver
The circuit in Figure 33 is a unique line driver circuit topology
used in professional audio applications and has been modified
for automotive audio applications. On a single +12 V supply,
the line driver exhibits less than 0.02% distortion into a 600 â¦
load across the entire audio band (not shown). For loads greater
than 600 â¦, distortion performance improves to where the cir-
cuit exhibits less than 0.002%. The design is a transformerless,
balanced transmission system where output common-mode
rejection of noise is of paramount importance. Like the trans-
former-based system, either output can be shorted to ground for
unbalanced line driver applications without changing the circuit
gain of 1. Other circuit gains can be set according to the equa-
tion in the diagram. This allows the design to be easily config-
ured for noninverting, inverting, or differential operation.
R2
10kâ
+12V
2
C1
22â®F 3 A1 1
VIN
R1
10kâ
A1, A2 = 1/2 OP279
GAIN
=
R3
R2
SET: R7, R10, R11 = R2
SET: R6, R12, R13 = R3
R3
10kâ
2
3 A2 1
R5
50â
R6
10kâ
R7
10kâ
+12V
+12V
6
7
A1 5
R8
100kâ
R9 C2
100kâ 1â®F
R11 R12
10kâ 10kâ
6
5 A2 7
R13
10kâ
R14
50â
C3
47â®F
VO1
RL
600â
C4
47â®F
VO2
Figure 33. A Single Supply, Balanced Line Driver for
Automotive Applications
Figure 32. A Single Supply, Remote Strain Gage Signal
Conditioner
â10â
REV. F
|
▷ |