3054

MULTIPLEXED

TWO-WIRE

HALL-EFFECT SENSOR ICs

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

In Figure 4, the ADDRESS input provides a TTL-compatible input

sensor supply). Bus reset control is also available in the form of a TTL-

and the positive input of the operational amplifier is set to the satura-

tion voltage of the transistor (approximately 0 V). This resets the bus.

A linear reading of the bus current is made possible by amplifying

given by:

This voltage is available at the ANALOG OUT terminal.

Bus Control Software

The processing of the bus current (available at ANALOG OUT) is

best done by feeding it into the A/D input of a microprocessor. If the

flexibility provided by a microprocessor is not desired, this signal could

be fed into threshold detection circuitry; e.g., comparator, and the

output used to drive a display.

Related References

1. G. AVERY, “Two-Terminal Hall Sensor,”

ASSIGNEE: Sprague

Electric Company, North Adams, MA, United States. Patent number

4,374,333; Feb. 1983.

2. T. WROBLEWSKI and F. MEISTERFIELD, “Switch Status

Monitoring System, Single-Wire Bus, Smart Sensor Arrangement

There Of,”

ASSIGNEE: Chrysler Motor Corporation, Highland Park, Ml,

United States. Patent number 4,677,308; June 1987.