SIO8 IC - ABCircuits

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ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104
SIO8 IC
Stand Alone UART IC
8 bits of input and 8 bits of output
General Description
The SIO8 IC is a stand alone UART designed to provide 8 bits of input and output data to 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 SIO8 has internal pull resistors on most
inputs to minimize additional parts. If the MODE pin is open or high, the data on the IA0-7 pins
are transmitted only after a byte is received on the SIN- pin. If the MODE pin is low, the SIO8 IC
transmits data anytime the inputs change or every of 100 mS, or 1000 mS, depending on the
state of the SPD pin. A positive pulse is generated on the RXP pin every time a byte is received
on the SIN- pin. The serial format to the SIO8 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
• Asynchronous serial control for 8
•
•
•
•
•
•
•
•
•
•
•
•
•
bits of input and 8 bits of output.
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.
Applications
• Input Output Expansion
• Remote control
• Process control
• Building Automation
• Off site monitoring
• Security systems
• Internet of things
• Machine control
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
Part Number 74C922-SO
Copyright © 2014 ABCircuits. Revised September 2014 Page 1 of 8
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ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104
Example Circuits
VCC
8 BITS INPUT/OUTPUT RS-232
1
.1
3
4
.1
VCC
5
SIO8
INPUT
INPUT
INPUT
INPUT
A7
A5
A3
A1
VDD
TXE
RXP
MODE
SINOA6
OA4
OA2
OA0
NC
IA6
IA4
IA2
IA0
28
27
26
25
24
23
22
21
20
19
18
17
16
15
11
10
12
9
VCC
V+
2
.1
C1C2+
V-
6
RS232
DB9S
.1
C2T1in
T1out
T2in
T2out
R1out
R1in
R2out
R2in
GND
A7
A5
A3
A1
NC
NC
SPD
SOUTOA7
OA5
OA3
OA1
NC
IA7
IA5
IA3
IA1
VSS
U2
SEE NOTES
1
2
3
4
5
6
7
8
9
8
14
7
13
8
15
OUTPUT
OUTPUT
OUTPUT
OUTPUT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
C1+
VCC
16
INPUT A2
INPUT A4
INPUT A6
OUTPUT A0
OUTPUT A2
OUTPUT A4
OUTPUT A6
U2= MAX232 FOR 5V RS232
U2= MAX3232 FOR 3V RS232
INPUT A0
8 BITS INPUT/OUTPUT ETHERNET
INPUT A2
INPUT A4
INPUT A6
OUTPUT A0
OUTPUT A2
OUTPUT A4
OUTPUT A6
+3.3
+3.3
OUTPUT
OUTPUT
OUTPUT
OUTPUT
A7
A5
A3
A1
INPUT
INPUT
INPUT
INPUT
A7
A5
A3
A1
NC
NC
SPD
SOUTOA7
OA5
OA3
OA1
NC
IA7
IA5
IA3
IA1
VSS
VDD
TXE
RXP
MODE
SINOA6
OA4
OA2
OA0
NC
IA6
IA4
IA2
IA0
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LANTRONIX
XPORT
1
2
3
4
5
6
7
8
GND
+3.3
-POR
OUT
IN
CP1
CP2
CP3
ETHERNET
SIO8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
INPUT A0
Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 2 of 8
TXD
RXD
GND
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8 BITS INPUT/OUTPUT RS-485
INPUT A2
INPUT A4
INPUT A6
OUTPUT A0
OUTPUT A2
OUTPUT A4
OUTPUT A6
VCC
VCC
4.7K
VCC
U2
SIO8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
OUTPUT A7
OUTPUT A5
OUTPUT A3
OUTPUT A1
INPUT A7
INPUT A5
INPUT A3
INPUT A1
NC
NC
SPD
SOUTOA7
OA5
OA3
OA1
NC
IA7
IA5
IA3
IA1
VSS
1
VDD
TXE
RXP
MODE
SINOA6
OA4
OA2
OA0
NC
IA6
IA4
IA2
IA0
28
27
26
25
24
23
22
21
20
19
18
17
16
15
2
3
4
RO
VCC
-RE
-DO/-RI
DE
DO / RI
DI
GND
8
7
RS485
6
5
U2 75176 FOR 5V
U2 MAX3485 FOR 3.3V
INPUT A0
NOTE: MODE PIN MUST BE OPEN FOR RS-485
8 BITS INPUT/OUTPUT USB
INPUT A2
INPUT A4
INPUT A6
OUTPUT A0
OUTPUT A2
OUTPUT A4
OUTPUT A6
VCC
.01 BEAD . 1
.1
20
4
17
FT232-SSOP
INPUT A7
INPUT A5
INPUT A3
INPUT A1
VDD
TXE
RXP
MODE
SINOA6
OA4
OA2
OA0
NC
IA6
IA4
IA2
IA0
28
27
26
25
24
23
22
21
20
19
18
17
16
15
15
CASE
REFER TO FT232 DATASHEET
FOR MORE DETAILS
19
27
28
8
24
USBM
USBP
-RST
OSCI
OSCO
NC
NC
GND
GND
GND
AGND
TEST
A7
A5
A3
A1
NC
NC
SPD
SOUTOA7
OA5
OA3
OA1
NC
IA7
IA5
IA3
IA1
VSS
16
TXD
RXD
DTR
-CTS
RTS
RI
DSR
DCD
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
1
5
2
11
3
6
9
10
23
22
13
14
12
7
18
21
25
26
SIO8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
VCC
VCCIO
3VOUT
USB
VCC
OUTPUT
OUTPUT
OUTPUT
OUTPUT
4.7
INPUT A0
Connection Diagram
SIO8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
NC
NC
SPD
SOUTOA7
OA5
OA3
OA1
NC
IA7
IA5
IA3
IA1
VSS
VDD
TXE
RXP
MODE
SINOA6
OA4
OA2
OA0
NC
IA6
IA4
IA2
IA0
28
27
26
25
24
23
22
21
20
19
18
17
16
15
Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 3 of 8
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ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104
Pin Description
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Description
NC
NC
SPD
SOUTOA7
OA5
OA3
OA1
NC
IA7
IA5
IA3
IA1
VSS
Pin #
28
27
26
25
24
23
22
21
20
19
18
17
16
15
Description
VDD
TXE
RXP
MODE
SINOA6
OA4
OA2
OA0
NC
IA6
IA4
IA2
IA0
OA0-7
These output bits are set when a byte is received on the SIN- pin. Output drivers may be
required for high power loads. The RXP pin generates a positive pulse after these bits are set.
SINThis is the serial input pin. It may be tied directly to the UART transmitter output of your UART or
microprocessor; to a RS -232 receiver such as the MAX232; an Ethernet interface such as the
Lantronix Xport; or a USB IC such as the FT232. This pin is high in the idle state, the input
format is 8 bits, 1 stop, no parity at 9600 BPS. Other formats and baud rates are available,
please contact the factory for information. The byte received on this pin will be transferred to the
OA0-7 pins, then a positive pulse is generated on the RXP output. This pin does not have an
internal pull up resistor. It is recommended your software periodically send the byte that is
transferred to the OA0-7 pins even if they have not changed to recover from communications
errors or power failures.
You can drive this input with any hexadecimal terminal program like REALTERM for testing and
development.
SOUTThis is the serial output pin. It may be tied directly to the UART receiver input of your UART or
microprocessor; to a RS -232 driver such as the MAX232; an Ethernet interface such as the
Lantronix Xport, or a USB IC such as the FT232. This pin sends the data on the IA0-7 pins,
adding start and stop bits. See the description of the MODE pin to determine when this data will
be sent. This pin is high in the idle state, the output format is 8 bits, 1 stop, no parity at 9600
BPS. Other output formats and baud rates are available, please contact the factory for
information.
You can monitor this output with any hexadecimal terminal program like REALTERM. Hyperterm
does not display in hexadecimal.
IA0-7
These are the input bits that will be transmitted on the SOUT- pin. These inputs have internal pull
up resistors.
Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 4 of 8
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MODE
This pin determines the transmit mode. If this pin is high or open, the SIO8 transmits the data on
the IA0-7 pins only after a byte is received on the SIN- pin. In this case, a byte must be written to
the OA0-7 pins to read the inputs on the IA0-7 pins.
If this pin is low or grounded, the SIO8 transmits data anytime the inputs on the IA0-7 pins
change, or the delay determined by the SPD pin times out. If the pin is low or grounded, a full
duplex channel must be used, and RS-485 may not be used for the interface, as RS-485 is half
duplex. This input has an internal pull up resistor.
SPD
This pin determines the delay before retransmit if the inputs do not change. If this pin is low or
grounded, the delay is 1000 mS, if this pin is high or open, the delay is 100 mS. This input has
an internal pull up resistor. If the MODE pin is high or open, this input has no effect.
RXP
This pin outputs a positive pulse after a byte is received on the SIN- pin and the bits are placed
on the OA0-7 pins.
TXE
This pin goes high while the byte on the SOUT- pin is being transmitted. This pin goes low again
after the stop bit has been sent. This pin is designed to drive the RE - (receiver enable) and DE
(driver enable) pins on a RS -485 driver IC. Please note, in RS-485 applications, an external pull
up resistor is required on the SIN- pin. Mode pin must be high or open for RS-485 applications,
requiring a write to the output byte first, to be able to read the new input byte.
VSS
Connect to system ground.
VDD
Connect to supply voltage of 2.4 to 5 volts. A .1 uF decoupling capacitor to ground is
recommended.
NOTES:
Make no connection to the NC pins. Pins 9 and 19 must be left unconnected.
Serial Input Stream
DATA STREAM
START
OUTPUT OA BITS
OA0
OA1
OA2
OA3
OA4
OA5
OA6
OA7 STOP
BIT CELLS
When a byte is received on the SIN- pin the byte is placed on the OA 0-7 pins. The SIO8
automatically removes start and stop bits from the data stream. The data is format is 9600 BPS,
8 bits, 1 stop, no parity. After the data is placed on the OA0-7 pins, the RXP pin generates a
positive pulse.
Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 5 of 8
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Serial Output Stream
DATA STREAM
START
INPUT IA BITS
IA0
IA1
IA2
IA3
IA4
IA5
IA6
IA7
STOP
BIT CELLS
(MODE=low or grounded)
When the input bits on IA0-7 change, or the 100 mS or 1000 mS (depending on the state of the
SPD pin) delay times out, the SIO8 transmits one byte on the SOUT- pin. The bits from IA0-7 are
transmitted. The SIO8 automatically adds start and stop bits to the data stream. The data is
transmitted at 9600 BPS, 8 bits, 1 stop, no parity.
(MODE=high or open)
After a byte is received on the SIN- pin the SIO8 transmits one byte on the SOUT- pin. The bits
from IA0-7 are transmitted. The SIO8 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
Tstg
Ta
V dd
V io
Imio
ESD
Storage Temperature
Operating Temperature
LU
Latch up current
V dd - V ss Voltage
Input Voltage
Maximum current into any pin
Electrostatic Discharge Voltage
Min
-55
-40
-0.5
Typical
Max
Units
25
+100
+85
+6.0
ºC
ºC
V
V
mA
V
Vss - 0.5
-25
2000
V dd +0.5
+50
200
Notes
Human Body Model
ESD
mA
DC Electrical Characteristics
Symbol
Description
V dd
Idd
V oh
V ol
V ih
V il
Ioh
Iol
Cio
Iil
Rpu
Supply Voltage
Supply Current
High Output Level
Low Output Voltage
Input High Level
Input Low Level
High Level Source Current
Low Level Sink Current
Capacitive load
Input leakage
Pull Up Resistors On Inputs
IA0-6
Min
Typical
Max
Units
5
5.25
8
V
mA
V
V
V
V
mA
mA
pF
nA
k?
2.4
V dd - 1.0
0.75
2.1
4
3.5
1
5.6
0.8
10
25
10
8
Notes
Note 1
Ioh=10 mA
Iol=25 mA
Note 1: Vdd=5VDC, all inputs and outputs open
Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 6 of 8
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Theory Of Operation
The SIO8 IC is a custom programmed microprocessor designed to monitor and control a serial
input/output stream.
When a byte is received on the SIN- pins, it is placed on the OA0-7 pins and generates a positive
pulse on the RXP pin.
If the mode pin is low or grounded anytime an input IA0-7 changes, or the 100 mS or 1000 mS
timer expires, the part transmits the data on the IA0-7 pins.
If the mode pin is high or open, the SIO8 IC transmits only after a byte is received on the SINpin.
The data is standard asynchronous format 8 data bits, 1 stop bit and no parity. Baud rate is 9600
BPS. It is recommended that the OA0-7 byte be sent periodically even if there is no change, to
recover from power failure or serial data errors.
Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 7 of 8
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ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104
Physical Dimensions SOIC-28
Physical Dimensions 28 Pin Dip Package (-DIP Suffix)
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Part Number SIO8
Copyright © 2014 ABCircuits. Revised September 2014 Page 8 of 8