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SIOA7 IC
Stand Alone UART IC
7 bits of input and 7 bits of output
Expandable and Addressable
General Description
The SIOA7 IC is a stand alone UART designed to provide 7 bits of input and output data.
(Expandable to 112 bits.) The SIOA7 may connect to RS-232, USB, RS-485, Ethernet or directly
to your UART. Outputs can be used to drive relays, logic, optocouplers or a transistors. Inputs
can be from switches, relay contacts, logic, optocouplers or a transistor switched to ground. The
SIOA7 has internal pull resistors on most inputs to minimize additional parts. After receiving an
address byte matching the ADR0-3 pins is received on the SIN- pin, the next bye received on the
SIN- pin is placed on the OA0-6 pins and the data on the IA0-6 pins are transmitted SOUT- pin.
A positive pulse is generated on the RXP pin every time a byte is placed on the OA0-6 pins.
More than one SIOA7 chip may be connected together to achieve up to 112 bits of input and
output. The serial format to the SIOA7 is standard asynchronous format, using 8 bits, 1 stop and
no parity at 9600 BPS. Other formats and encoding are available, contact the factory. A .1 uF
bypass capacitor is suggested across the VDD and VSS pins. The part uses the standard 28 pin
.3 inch width SOIC package.
Features
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Asynchronous serial control for 7
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bits of input and 7 bits of output,
expandable to 112 bits.
Can connect with RS-232, RS -485,
USB or Ethernet or UART.
Inputs can be switches, relay
contacts, optocouplers, and logic.
On chip input pull up resistors on
most inputs.
Outputs can be used to drive relays,
transistors, optocouplers, and logic.
No external parts required.
Low power consumption 5 mA
typical.
Supply voltage 2.4 to 5.25 volts.
All timing internally generated.
TTL and CMOS compatible outputs.
Part is in full production.
SOIC and DIP 28 Pin Package.
ROHS Compliant
Low EMI
Applications
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Input Output Expansion
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Remote control
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Process control
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Building Automation
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Off site monitoring
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Security systems
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Internet of things
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Machine control
Part Number 74C922-SO
Copyright © 2014 ABCircuits. Revised September 2014 Page 1 of 10