Modem Receiver Circuit

Modem Receiver Circuit

Chip Picture Here

Courtesy 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