The MIC 3 Click is a Click board™ that features the SSM2167-1RMZ-R7, a Microphone Preamplifier, from Analog Device. This Click board™ is a low voltage Microphone preamplifier with Variable compression and noise gating. The MIC 3 Click is a very easy solution to work with it, which makes it an ideal solution for using it in desktop, portable or palmtop computers, telephone conferencing, communication headsets, two-way communication, surveillance system where the microphone is needed, stethoscope, karaoke and DJ mixers.

The MIC 3 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

The MIC 3 Click based on the SSM2167-1RMZ-R7 from Analog Devices is a complete and flexible solution for conditioning microphone inputs in personal electronics and computer audio systems. The Click board™ is also excellent for improving vocal clarity in communications and public address systems. A low noise voltage-controlled amplifier (VCA) provides a gain that is dynamically adjusted by a control loop to maintain a set compression characteristic. The MIC 3 Click provides two operation settings, these settings are selectable with NOISE G. COMPR. jumpers.

The MIC 3 Click provides four different preset values of the noise gate threshold. Experiment with these values by varying the gate. The noise gate threshold is a programmable point using an external resistor. The downward expansion threshold may be set between −40 dBV and −55 dBV, as shown in Table.

Noise Gate (dBV):

• -40
• -48
• -54
• -55

Value of RGATE:

• 0 Ω
• 1 Ω
• 2 Ω
• 3 Ω

The Click board™ provides four different preset values of the compression ratio. Changing the scaling of the control signal fed to the VCA causes a change in the circuit compression ratio.Lowering RCOMP gives smaller compression ratios as indicated in Table. Automatic Gain Control (AGC) performance is achieved with compression ratios between 2:1 and 10:1, and is dependent on the application. Shorting RCOMP disables the AGC function, setting the compression equal to 1:1.

Compression Ratio:

• 1:1
• 2:1
• 5:1
• 10:1

Value of RCOMP:

• 0 Ω
• 15 Ω
• 75 Ω
• 174 Ω

The MIC 3 Click is designed to work with either 3.3V or 5V power supply. It communicates with the target MCU over GPIO pin on the mikroBUS™. The supply current of the SSM2167 can be reduced to under 10 μA by applying an active low.

• Interface: GPIO
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 3.3V or 5V

• Schematic
• mikroSDK
• GitHub