Modem Receiver Circuit


http://cmosedu.com/jbaker/projects/recvr.jpg

Designed and laid out in 1997 by Jake Baker for Tower Semiconductor


The cell pictured above is a Receiver circuit for use in a high speed modem.

Design Specifications:

  • Stage 1
    • Differential Amplifier with linear range of 0.7V - VDD-0.7V
    • Offset voltage of +/- 1.5mV
    • VDD=5V +/- 10%
    • DC Current < 0.3mA
    • Amplification 7-15 (typically 10)
    • Output Range is 1V to VDD - 1V
    • Frequency response up to 1MHz
    • PSRR > 70dB
    • Input current < 1uA
  • Stage 2
    • RC type passive LPF
    • Linear Range of 0V - VDD
    • RC factor > 3uS
    • Noise from VDD or GND is halved at the LPF output
  • Stage 3
    • S/H Circuit
    • Input voltage range 1V to VDD - 1V
    • Sampling frequency 0.25uS typically
  • Stage 4
    • Comparator
    • Full Swing output
    • Response time is 10nS
    • VDD = 5V +/- 10%
    • DC current < 0.3mA

The cell was designed using a 0.6 micron, double metal, single poly process. 


Last Updated Tue: May 19, 1997

 

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