OM4031T

Features:

· External clock frequency 30 to 80 kHz (typ. 38.4 kHz)
· Supported data rates 600, 1200, 2400 and 4800 bits/s(typ.)
· Double bandwidth option (not for 4800 bits/s)
· Schmitt-triggered inputs for optimum slope tolerance
· Enable input for power-down mode
· Open-drain output (3-state in power-down mode)
· No external components required
· Single supply voltage from 1.8 to 6.0 V
· Very low operating current (1.5 mA typ.)
· Operating temperature from -10 to +70 °C.


Application

· Telemetry data receivers
· RF security systems
· Low-bit-rate radio data links
· Paging applications of UAA2080 and UAA2082 with
  software decoding.


Pinout




Description

The OM4031T is intended for performance enhancement of FSK data receivers that do not have a built-in post-detection filter.
OM4031T contains a digital moving average filter to remove noise from the demodulated data. When operated from a 38.4 kHz external clock it can handle data rates of 600, 1200 and 2400 bits/s at an oversampling rate of 16. The filter bandwidth can be doubled to ease the search for bit synchronization on the output data.

To allow for jitter in the input data, a 12-bit sample is taken for the majority decision. Doubling the filter bandwidth is realised by taking the majority out of 6 samples (2400 bits/s) or by doubling the sampling rate (600 and 1200 bits/s).

An input data rate of 4800 bits/s is supported at 8 times oversampling and normal bandwidth.

All inputs are Schmitt-triggered to ensure reliable operation even at signals with long rise/fall times.