Description

The STWCQ142E is an integrated circuit (IC) chip categorized under the product category of IC chips. It is specifically designed to function as a low power combined PCM CODEC/FILTER device to implement the audio front-end functions required by low voltage/low power consumption digital cellular terminals. STWCQ142E can be configured either as a 14-bit linear or as an 8-bit companded PCM coder.

Specifications and features

• 14 bit linear analog to digital and digital to analog converters
• 8 bit companded analog to digital and digital to analog converters ALAW or µ-LAW
• Transmit and receive band-pass filters
• Active antialias noise filter
• One microphone biasing output
• Remote control (remocon) function
• Three switchable microphone amplifier inputs gain programmable: 0 . . 42.5 dB amplifier, 1.5 dB steps (+ mute)
• Earpiece audio output attenuation programmable: 0 . . 30 dB, 2 dB steps
• External audio output attenuation programmable: 0 . . 30 dB, 2 dB steps
• Driving capability: 140mW over 8Ω
• Transient suppression signal during power on and during amplifier switching
• Internal programmable sidetone circuit attenuation programmable: 16 dB range, 1 dB step
• Internal ring, tone and DTMF generator, sinewave or squarewave waveforms. Attenuation programmable: 27dB range, 3dB step. Three frequency ranges:
  • 3.9Hz . . . . 996Hz, 3.9Hz step
  • 7.8Hz . . . . 1992Hz, 7.8Hz step
  • 15.6Hz . . . . 3984Hz, 15.6Hz step
• Programmable pulse width modulated buzzer driver output
• Single 2.7V to 3.3V supply
• Extended temperature range operation (*) -40°C to 85°C
• 1.0µW standby power (typ. at 2.7V)
• 13mW operating power (typ. at 2.7V)
• 1.8V to 3.3V CMOS compatible digital interfaces
• Programmable PCM and control interface microwire compatible

Application Scenarios

The STWCQ142E IC chip is commonly used in the following:

• GSM/DCS1800/PCS1900/JDC digital cellular telephones
• CDMA cellular telephones
• DECT/CT2/PHS digital cordless telephones
• Battery-operated audio front-ends for DSPs

Comparison

• Low power consumption
• High performance
• Extended temperature range operation
• Programmable functions
• PCM interface supports both non-delayed and delayed frame synchronization modes
• Complete CODEC and FILTER system including transmit and receive band-pass filters and active antialias noise filter
• Multiple microphone amplifier inputs with programmable gain
• Programmable sidetone circuit and ring/tone/DTMF generator capabilities

• Restricted audio output attenuation of 0 to 30 dB, 2 dB steps
• Single 2.7V to 3.3V supply, not suitable for other voltage levels
• Limited to specific phone and audio front-end applications