Turning Ideas Into Reality 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 Turning Ideas Into Reality 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 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 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 Turning Ideas Into Reality 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 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 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 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 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 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 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 Turning Ideas Into Reality 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) Close but not quite? Our products are software based, we can modify existing parts to fit your needs at a minimal cost or create new parts designed to your specifications. Email us and we can make a chip for you! For the latest version of this spec sheet, visit www.abcircuits.com Design Services Available We can quickly turn your idea into a chip, a pc board, or a finished product. Contact us with your needs and specifications. Part Number SIO8 Copyright © 2014 ABCircuits. Revised September 2014 Page 8 of 8