DESCRIPTION
The NE/SA5750 is a high performance low power audio signal processing system. The NE/SA5750 subsystems include a low noise microphone preamplifier with adustable gain, a noise cancellation switching amplifier with adjustable threshold, a voice operated transmitter (VOX) switch, VOX control, an audio compressor with buffered input, audio expandor, a unity gain power amplifier to drive a speaker, a summing power amplifier for sidetone attenuation and headphone (earpiece) drive, and an internal bandgap voltage regulator with power down capability. When used with Philips Semiconductors NE/SA5751, the complete audio processing function of an AMPS or TACS cellular telephone is easily implemented. The NE/SA5750 can also be used without the NE/SA5751 in a wide variety of radio communications applications.

FEATURES
• High performance
• 5V supply
• Adjustable VOX and noise cancellation threshold
• Adjustable gain preamplifier
• Audio companding
• ESD protected
• Open collector VOX output
• Logic inputs CMOS compatible
• Power down mode
• Built-in drivers for speaker and earpiece
• Few external components
• SOL and DIP packages

BenefitS
• Very compact applications
• Long battery life in portable equipment
• Complete cellular audio function with the SA5751

APPLICATIONS
• Cellular radio
• Mobile communications
• High performance cordless telephones
• 2-way radio