SSM2167-1RMZ-REEL

Overview

The SSM2167-1RMZ-REEL is a low voltage microphone preamplifier with variable compression and noise gating, manufactured by Analog Devices Inc. It operates on a single 3 V supply and features a 10-lead MSOP package. The device includes a low noise voltage controlled amplifier (VCA) providing up to 40 dB dynamic gain range and an internal RMS level detector. Key electrical parameters include a 20 nV/√Hz voltage noise density, 1 MHz gain bandwidth product, and 0.2% THD + N at 1 kHz. Supply current ranges from 2.3 mA to 5 mA, dropping below 8 µA in shutdown mode.

Feature Summary

• Integrates complete microphone conditioning including amplification, limiting, variable compression, and noise gating within a single IC.
• Features a low noise voltage controlled amplifier (VCA) with adjustable compression ratio and downward expansion threshold.
• Includes an automatic limiting feature to prevent ADC overload and eliminate popping sounds.
• Provides a low power shutdown mode for battery-powered applications.

Applications

• Desktop, portable, or palmtop computers
• Telephone conferencing systems
• Communication headsets
• Two-way communications equipment
• Surveillance systems

Procurement Notes

Verify the specific suffix -REEL indicates reel packaging when sourcing. Confirm RoHS compliance status via the manufacturer's ordering guide. Ensure the operating temperature range of −40°C to +85°C matches your environmental requirements. Check for any regional shipping restrictions or availability limitations before finalizing procurement plans.

Selection Notes

Select this component for voice-band applications requiring integrated dynamic range processing. Consider the fixed rotation point of 63 mV rms and the need for external resistors to set compression ratios and noise gate thresholds. Evaluate PCB layout constraints due to high gain capabilities and wide bandwidth to minimize capacitive feedback between input and output traces.

Part Context

This part belongs to the SSM2167 family of microphone conditioners designed for personal electronics and computer audio systems. It improves vocal clarity in communications and public address systems by optimizing signal levels prior to digitization. The device eliminates the need for additional gain or attenuation in the digital domain through its flexible analog conditioning capabilities.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

FAQ

How is the compression ratio adjusted?

The compression ratio is set by connecting a single resistor (RCOMP) between Pin 8 and VDD. Values range from 0 Ω for 1:1 to 175 kΩ for 10:1 compression.

What is the function of the SHUTDOWN pin?

Applying an active low, CMOS-compatible digital signal to Pin 3 reduces the supply current to typically less than 2 µA, placing the device in a low-power state.

How is the noise gate threshold configured?

The downward expansion threshold is programmed using an external resistor (RGATE) connected between Pin 7 and VDD, allowing adjustment between −40 dBV and −55 dBV.