Product Description
The MIC 3 Click Board™ is 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.
How Does The MIC 3 Click Board™ Work?
The MIC 3 Click Board™ 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) |
Value of RGATE |
| -40 |
0 Ω |
| -48 |
1 Ω |
| -54 |
2 Ω |
| -55 |
3 Ω |
The MIC 3 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 |
Value of RCOMP |
| 1:1 |
0 Ω |
| 2:1 |
15 Ω |
| 5:1 |
75 Ω |
| 10:1 |
174 Ω |
The MIC 3 Click Board™ 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.
SPECIFICATIONS
| Type |
Microphone |
| Applications |
Karaoke and DJ mixers,Desktop, portable, or palmtop computers,Telephone conferencing. |
| On-board modules |
SSM2167-1RMZ-R7, Low Voltage Microphone Preamplifier from Analog Device. |
| Key Features |
Adjustable noise gate threshold,Adjustable compression ratio. |
| Interface |
GPIO |
| Compatibility |
mikroBUS |
| Click board size |
L (57.15 x 25.4 mm) |
| Input Voltage |
3.3V or 5V |
PINOUT DIAGRAM
This table shows how the pinout of the MIC 3 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
| Notes |
Pin |
 |
Pin |
Notes |
| NC |
1 |
AN |
PWM |
16 |
NC |
| NC |
2 |
RST |
INT |
15 |
NC |
| Shutdown |
SHD |
3 |
CS |
RX |
14 |
NC |
| NC |
4 |
SCK |
TX |
13 |
NC |
| NC |
5 |
MISO |
SCL |
12 |
NC |
| NC |
6 |
MOSI |
SDA |
11 |
NC |
| Power Supply |
3.3V |
7 |
3.3V |
5V |
10 |
5V |
Power Supply |
| Ground |
GND |
8 |
GND |
GND |
9 |
GND |
Ground |
ONBOARD SETTINGS AND INDICATORS
| Label |
Name |
Default |
Description |
| LD1 |
PWR |
- |
Power LED Indicator |
| - |
NOISE G. COMPR |
1:1, -40 |
Select noise gate threshold and compression ratio. |
