OP183 Datasheet, PDF (9/12 Pages) Analog Devices – 5 MHz Single-Supply Operational Amplifiers

APPLICATIONS
OP183 Offset Adjust
Figure 36 shows how the OP183’s offset voltage can be adjusted by
connecting a potentiometer between Pins 1 and 5, and connecting
the wiper to V_EE. The recommended value for the potentiometer is
10 kΩ. This will give an adjustment range of approximately ± 1 mV.
If larger adjustment span is desired, a 50 kΩ potentiometer will
yield a range of ± 2.5 mV.
V_CC
3
7
OP183 6
V_OS
2
1
5
4
V_EE
Figure 36. OP183 Offset Adjust
Phase Reversal
The OP183 family is protected against phase reversal as long as
both of the inputs are within the range of the positive supply and
the negative supply minus 0.6 volts. However if there is a possibility
of either input going beyond these limits, then the inputs should be
protected with a series resistor to limit input current to 2 mA.
Direct Access Arrangement
The OP183/OP283 can be used in a single supply Direct Access
Arrangement (DAA) as is shown in Figure 37. This figure shows a
portion of a typical DAA capable of operating from a single +5 volt
supply and it should also work on +3 volt supplies with minor
modifications. Amplifiers A2 and A3 are configured so that the
transmit signal TXA is inverted by A2 and is not inverted by A3.
This arrangement drives the transformer differentially so that the
drive to the transformer is effectively doubled over a single amplifier
arrangement. This application takes advantage of the OP183/283’s
ability to drive capacitive loads, and to save power in single supply
applications.
300pF
0.1µF
RXA
Ω37.4kΩ
A1
OP283
Ω20kΩ
0.0047µF
Ω3.3kΩ
A2
OP283
Ω20kΩ
Ω475Ω
0.1µF
TXA
Ω20kΩ
2.5V_REF
Ω22.1kΩ
750pF
Ω20kΩ
Ω20kΩ
A3
OP283
0.33µF
OP183/OP283
+5 Volt Only Stereo DAC for Multimedia
The OP283’s low noise and single supply capability are ideally
suited for stereo DAC audio reproduction or sound synthesis
applications such as multimedia systems. Figure 38 shows an 18-bit
stereo DAC output setup that is powered from a single +5 volt
supply. The low noise preserves the 18-bit dynamic range of the
AD1868. For DACs that operate on dual supplies, the OP283 can
also be powered from the same supplies.
+5V SUPPLY
AD1868
1
VL
18-BIT
DAC
2
LL
3
18-BIT
DL ^SERIAL
REG.
4
CK
VREF
VBL
16
15
14
VOL
13
5 DR
18-BIT
6 LR SERIAL
REG.
7 DGND
VBR ^18-BIT
8
DAC
AGND 12
VREF
11
VOR
10
VS 9
Ω7.68k
Ω
330pF
Ω7.68kΩ
330pF
Ω9.76kΩ
3
8
1/2 OP283 ¹
2
4
100pF
220µF
LEFT
CHANNEL
OUTPUT
Ω47kΩ
Ω7.68kΩ
Ω7.68kΩ
Ω9.76kΩ
100pF
6
1/2 OP283 7
5
220µF
RIGHT
CHANNEL
OUTPUT
Ω47kΩ
Figure 38. +5 Volt Only 18-Bit Stereo DAC
Low Voltage Headphone Amplifiers
Figure 39 shows a stereo headphone output amplifier for the
AD1849 16-bit SoundPort^® Stereo Codec device. The pseudo-
reference voltage is derived from the common-mode voltage
generated internally by the AD1849, thus providing a convenient
bias for the headphone output amplifiers.
V _REF
ΩOPTIONAL
GAIN
1kΩ
10µF
LOUT1L 31
Ω10kΩ
L VOLUME
CONTROL
Ω5kΩ
+5V
1/2 OP283
Ω16Ω ^220µF
Ω47kΩ
HEADPHONE
LEFT
AD1849
V _REF
+5V
1/2 OP283
CMOUT ¹⁹
Ω10kΩ
LOUT1R 29
10µF
R VOLUME
CONTROL
1/2 OP283
Ω16Ω 220µF
Ω47kΩ
HEADPHONE
RIGHT
Ω1kΩ
Ω5kΩ
OPTIONAL
GAIN
V _REF
Figure 39. Headphone Output Amplifier for Multimedia
Sound Codec
SoundPort is a registered trademark of Analog Devices Inc.
Figure 37. Direct Access Arrangement
REV.B
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