op113ep Analog Devices, Inc., op113ep Datasheet - Page 17

• Manufacturer Part Number: op113ep
• Description: Low Noise, Low Drift Single-supply Operational Amplifiers
• Manufacturer: Analog Devices, Inc.

LOW VOLTAGE HEADPHONE AMPLIFIERS
Figure 49 shows a stereo headphone output amplifier for the
AD1849 16-bit SOUNDPORT® stereo codec device.
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.
LOW NOISE MICROPHONE AMPLIFIER FOR
MULTIMEDIA
The OPx13 family is ideally suited as a low noise microphone
preamp for low voltage audio applications. Figure 50 shows a
gain of 100 stereo preamp for the AD1849 16-bit SOUNDPORT
stereo codec chip. The common-mode output buffer serves as a
phantom power driver for the microphones.
LOUT1R
LOUT1L
AD1849
CMOUT
Figure 49. Headphone Output Amplifier for Multimedia Sound Codec
19
31
29
V
REF
10µF
10µF
10kΩ
10kΩ
V
REF
R VOLUME
CONTROL
L VOLUME
CONTROL
OPTIONAL
GAIN
1kΩ
1kΩ
V
REF
OPTIONAL
GAIN
–
+
OP213
OP213
–
+
1/2
1/2
OP213
5kΩ
5kΩ
5V
5V
1/2
–
+
16Ω
16Ω
220µF
220µF
47kΩ
+
+
47kΩ
1
The
HEADPHONE
LEFT
HEADPHONE
RIGHT
Rev. F | Page 17 of 24
CONDENSER
PRECISION VOLTAGE COMPARATOR
With its PNP inputs and 0 V common-mode capability, the
OPx13 family can make useful voltage comparators. There is
only a slight penalty in speed in comparison to IC comparators.
However, the significant advantage is its voltage accuracy. For
example, V
with CMRR and PSRR exceeding 100 dB, while operating from
a 5 V supply. Standard comparators like the 111/311 family
operate on 5 V, but not with common mode at ground, nor with
offset below 3 mV. Indeed, no commercially available single-
supply comparator has a V
1
CONDENSER
SOUNDPORT is a registered trademark of Analog Devices, Inc.
ELECTRET
ELECTRET
Figure 50. Low Noise Stereo Microphone Amplifier for Multimedia Sound
INPUT
RIGHT
INPUT
LEFT
MIC
MIC
OS
can be a few hundred microvolts or less, combined
20Ω
20Ω
10µF
10µF
OP213
+
+
5V
1/2
OS
50Ω
50Ω
–
+
10kΩ
10kΩ
less than 200 μV.
Codec
OP113/OP213/OP413
100Ω
OP213
+
–
100Ω
10kΩ
1/2
OP213
–
+
1/2
10kΩ
5V
17
19
15
AD1849
MINL
CMOUT
MINR