SSM2166 Datasheet | Analog

FEATURES plete microphone conditioner in a 14-lead SOIC package Single 5 V operation Adjustable noise gate threshold pression ratio set by external resistor Automatic limiting feature - prevents ADC overload Adjustable release time Low noise and distortion Power-down feature 20 k Hz bandwidth (±1 d B) APPLICATIONS Microphone preamplifiers/processors puter sound cards Public address/paging systems munication headsets Telephone conferencing Guitar sustain effects generators puterized voice recognition Surveillance systems Karaoke and DJ mixers GENERAL DESCRIPTION The SSM2166 integrates a plete and flexible solution for conditioning microphone inputs in puter audio systems. It is also excellent for improving vocal clarity in munications 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 pression characteristic. The pression ratio is set by a single resistor and can be varied from 1:1 to over 15:1 relative to a user-defined rotation point; signals above the rotation point are limited to prevent overload and to eliminate popping. In the 1:1 pression setting, the SSM2166 can be programmed with a fixed gain of up to 20 d B; this gain is in addition to the variable gain in other pression settings. The input buffer can also be configured for front-end gains of 0 d B to 20 d B. A downward expander (noise gate) prevents amplification of noise or hum. This results in optimized signal levels prior to digitization, thereby eliminating the need for additional gain or attenuation in the digital domain that may add noise or impair accuracy of speech recognition algorithms. The pression ratio and time constants are set externally. A high degree of flexibility is provided by the VCA gain, rotation point, and noise gate adjustment pins. The SSM2166 is an ideal panion product for audio codecs used in puter systems. The SSM2166 is available in a 14-lead SOIC package and is guaranteed for...