5v mic preamp - SSM2019.zip
author: imadaily
2 layer board of 1.40 x 0.41 inches (35.5 x 10.3 mm)
Uploaded:
October 14, 2017
Shared:
October 29, 2017
Total Price:
$2.80
Tested, seems to work fine. (Updated 31 Oct 17)
A microphone pre-amp PCB designed to fit within the casing of an old dynamic mic and use USB for power.
An isolated MuRata DC-DC converter (NMA0515DC) boosts the 5v input to +/-15V required for the amplifier.
The op-amp used is a SSM2019BRNZ in 8-pin SOIC package.
The gain is set with a resistor (330R for 30dB or 100R for 40dB). Refer to the SSM2019 datasheet for further suitable gain resistor values.
C3 (220pf) sits across pins 2/3 to reduce problems with RF noise.
R1/R2 (6k8) connect from the mic input to ground to provide a pseudo-differential input. Read the datasheet for more info.
A LC filter is used to smooth the output of the DC-DC (bridge across L1 & L2 if not used)
L1/L2: MuRata 82224C C1/C2: 1uF low esr in 0805 pkg
If anyone makes one or has questions I can be found @imadaily on twitter
Tested, seems to work fine. (Updated 31 Oct 17)
A microphone pre-amp PCB designed to fit within the casing of an old dynamic mic and use USB for power.
An isolated MuRata DC-DC converter (NMA0515DC) boosts the 5v input to +/-15V required for the amplifier.
The op-amp used is a SSM2019BRNZ in 8-pin SOIC package.
The gain is set with a resistor (330R for 30dB or 100R for 40dB). Refer to the SSM2019 datasheet for further suitable gain resistor values.
C3 (220pf) sits across pins 2/3 to reduce problems with RF noise.
R1/R2 (6k8) connect from the mic input to ground to provide a pseudo-differential input. Read the datasheet for more info.
A LC filter is used to smooth the output of the DC-DC (bridge across L1 & L2 if not used)
L1/L2: MuRata 82224C C1/C2: 1uF low esr in 0805 pkg
If anyone makes one or has questions I can be found @imadaily on twitter
