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ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104

Part Number SIO7

Copyright © 2014 ABCircuits. Revised September 2014 Page 5 of 7

Serial Output Stream

IA4

START

IA2

IA6

IA3

IA0

BIT CELLS

DATA STREAM

IA5

0

IA1

STOP

INPUT IA BITS

When the input bits on IA0-6 change, or the 100 mS delay times out, the SIO7 transmits one byte

on the SOUT- pin. The bits from IA0-6 are transmitted, the eighth bit is a zero. The SIO7

automatically adds start and stop bits to the data stream. The data is transmitted at 9600 BPS, 8

bits, 1 stop, no parity.

Absolute Maximum Ratings

Symbol

Description

Min

Typical

Max

Units

Notes

Storage Temperature

-55

25

+100

ºC

Operating Temperature

-40

+85

ºC

-0.5

+6.0

V

Input Voltage

V

Maximum current into any pin

-25

+50

mA

ESD

Electrostatic Discharge Voltage

2000

V

Human Body Model

ESD

LU

Latch up current

200

mA

DC Electrical Characteristics

Symbol

Description

Min

Typical

Max

Units

Notes

Supply Voltage

2.4

5.25

V

Supply Current

5

8

mA

Note 1

High Output Level

V

Low Output Voltage

0.75

V

Input High Level

2.1

V

Input Low Level

0.8

V

High Level Source Current

10

mA

Low Level Sink Current

25

mA

Capacitive load

3.5

10

pF

Input leakage

1

nA

Pull Up Resistors On Inputs

IA0-6

4

5.6

8

k?

Note 1: Vdd=5VDC, all inputs and outputs open

Theory Of Operation

The SIO7 IC is a custom programmed microprocessor designed to monitor a serial input/output

stream. When a byte is received, bit 8 is checked. If bit 8 is zero, the byte is placed on the OA0-

6 pins, otherwise the byte is ignored.

Anytime an input IA0-6 changes, or the 100 mS timer expires, the part transmits the data on the

IA0-6 pins. Bit 8 of the transmitted byte is a zero.