AN49 Digital Audio Amplifier Gain Control using Logarithmic POTs

The Datasheet Archive - 100 Million Datasheets from 7500 Manufacturers.

AN49 Digital Audio Amplifier Gain Control using Logarithmic POTs

Datasheet Thumbnail

Top Searches for this datasheet

Applications Staff, January 1994 Often power amplifier stage communications device located some distance from control panel. typical solution mount volume control front panel pair shielded cables back power amplifier stage. better solution Xicor X9314 logarithmic taper digitally controlled potentiometer. This completely eliminates need shielded cables since digital located printed circuit board near level input stages power amplifier. up/down volume switches located yards away these merely speed signals. Circuit Description Figure shows X9314 with voltage LM386 power amplifier. This circuit will produce 250mW audio power with only source. Figure similar circuit that uses higher power LM380 capable delivering over audio source available. Either circuit will provide plenty sound intercom, communications, monitoring applications. circuit would preferred when higher ambient noise present, such automobile. 74HC132 quad Schmitt nand gate (U2) plus discretes that required interface X9314W POT. When either pushbutton switch, depressed, output will HIGH. This immediately brings output which enables POT. After short delay
AN49
Digital Audio Amplifier Gain Control using Logarithmic POTs
determined astable multivibrator (U2C) will begin generating increment pulses. frequency oscillation (and consequently speed which volume controlled) determined values shown will advance X9314 through wiper taps about seconds. changed from suit your preference. When pushbutton switches released, delay release X9314 chip select order ensure that last increment pulse written. X9314W needs little else apply most audio circuits, been included here remove component that present input signal. Also, lowpass filter removes residual high frequency noise from digital pot's internal charge pumps. LM380 LM386 power amplifiers have fixed gains 34dB 26dB respectively. gain LM386 increased 46dB (X200) connecting 10uF capacitor from pins positive pole capacitor should connected output snubber network required stability should located close output power amplifier. These amplifiers have fairly high gain wide bandwidths, careful with trace lengths. connections these amplifiers should short direct possible.
6586-1.0 03/20/95
Xicor, Inc. 1511 Buckeye Drive Milpitas, 95035 (408) 432-8888
AN49-1
Xicor
AN49
Figure Voltage Audio Amplifier
6586-1.0 03/20/95
AN49-
Xicor
AN49
Figure Watt Audio Amplifier
6586-1.0 03/20/95
AN49-3

AN49 Digital Audio Amplifier Gain Control using Logarithmic POTs

Top Searches for this datasheet

Other recent searches