SSM2135SZ-REEL Analog Devices Inc, SSM2135SZ-REEL Datasheet - Page 11

• Manufacturer Part Number: SSM2135SZ-REEL
• Description: IC,Operational Amplifier,DUAL,BIPOLAR/JFET,SOP,8PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of SSM2135SZ-REEL

• Amplifier Type: Audio
• Number Of Circuits: 1
• Slew Rate: 0.9 V/µs
• Gain Bandwidth Product: 3.5MHz
• Current - Input Bias: 300nA
• Voltage - Input Offset: 200µV
• Current - Supply: 3.7mA
• Current - Output / Channel: 30mA
• Voltage - Supply, Single/dual (±): 4 V ~ 36 V, ±2 V ~ 18 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Low Noise Microphone Preamplifier
The 5.2 nV/√Hz input noise in conjunction with low distortion
make the SSM2315 an ideal device for amplifying low level signals
such as those produced by microphones. Figure 34 illustrates a
stereo microphone input circuit feeding a multimedia sound
codec. The gain is set at 100 (40 dB), although it can be set to
other gains depending on the microphone output levels. Figure 33
shows the harmonic distortion performance of the preamplifier
with 1 V rms output, while operating from a single 5 V supply.
The SSM2135 is biased to 2.25 V by the V
codec. The same voltage is buffered by the 2N4124 transistor to
provide phantom power to the microphone. A typical electrets
condenser microphone with an impedance range of 100 Ω to
1 kΩ works well with the circuit. This power booster circuit can
be omitted for dynamic microphone elements.
RIGHT CHANNEL
LEFT CHANNEL
MIC IN
MIC IN
Figure 34. Low Noise Microphone Preamp for Multimedia Sound Codec
REF
pin of the
2N4124
2kΩ
2kΩ
10µF
10µF
5V
10kΩ
10kΩ
AD1845
Rev. G | Page 11 of 16
100Ω
100Ω
10µF
2
3
5
6
10kΩ
10kΩ
4
5V
8
SSM2135
SSM2135
10µF
0.1µF
1/2
1/2
1
7
0.1µF
0.01
0.1
5V
1
10
V
A
V
80kHz LOW-PASS FILTER
S
OUT
V
= 5V
= 40dB
35/36
34/37
Figure 33. MIC Preamp THD + N Performance
= 1V rms
29
32
28
GNDA
V
R_MIC
L_MIC
V
REF
CC
AD1845
100
FREQUENCY (Hz)
1k
SSM2135
10k
20k