SSM2167-1RMZ-R7

Overview

The SSM2167-1RMZ-R7 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. Key electrical parameters include a 20 kHz bandwidth, 0.2% THD + N, and a fixed gain of 18 dB. The device provides a dynamic gain range of 40 dB, adjustable compression ratios from 1:1 to over 10:1, and an automatic limiting feature to prevent ADC overload. Supply current ranges from 2.3 mA to 5 mA, dropping below 2 µA in shutdown mode.

Feature Summary

• Integrates a complete microphone conditioning system including amplification, variable compression, downward expansion (noise gating), and limiting within a single chip.
• Features a true RMS level detector with user-adjustable averaging time constants to control attack and release times for optimal signal dynamics.
• Includes a low power shutdown mode that reduces supply current significantly while placing input and output circuitry in a high impedance state.
• Provides automatic limiting above the internal rotation point to prevent clipping and eliminate popping sounds before digitization.

Applications

• Desktop, portable, or palmtop computers
• Telephone conferencing systems
• Communication headsets
• Two-way communications equipment
• Karaoke and DJ mixers

Procurement Notes

Verify the specific suffix R7 indicates reel packaging when sourcing components. Confirm RoHS compliance status as indicated by the Z suffix in the part number. Ensure the operating temperature range meets the extended industrial requirements of -40°C to +85°C for your specific application environment.

Selection Notes

Select this component for voice-band applications requiring integrated dynamic range processing without external digital domain gain adjustments. Consider the 10-lead MSOP package for space-constrained designs. Evaluate the need for external resistors to set compression ratios and noise gate thresholds based on the desired audio characteristics.

Part Context

This part belongs to the SSM2167 family of microphone preamplifiers designed for personal electronics and computer audio systems. It serves as a flexible solution for conditioning microphone inputs to improve vocal clarity in communications and public address systems. The device eliminates the need for additional analog gain or attenuation stages prior to analog-to-digital conversion.

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 a 1:1 ratio to 175 kΩ for a 10:1 ratio.

What determines the attack and release times of the compressor?

The release time is controlled by the external capacitor (CAVG) connected to Pin 6, while the attack time is primarily determined by internal circuitry that responds quickly to large level changes.

How does the noise gate function?

The noise gate acts as a downward expander, preventing amplification of background noise below a programmable threshold set by an external resistor (RGATE) on Pin 7.