18 pin dip d3 data rx - tx 7 9 8 11 a2 1 18 16 14 d6 d0 6 2 mode ir - rf enc-dec d7 latch - mom 5 4 13 3 d1 d2 15 12 a1 gnd 10 a3 d4 a0 vcc d5 17 ST12 codec ? ir/rf remote control encoder/decoder ic 1. overview ST12 codec is radio frequency and infrared encoder/decoder ic for remote control applications having unique features and flexibility not available with other remote control encoder decoder ics. ST12 is truly a single-chip remote control solution. transmitter and receiver can operate over radio frequency or infrared having four address and eight data bits. transmission and reception over infrared is achieved by commonly available infrared led- detector and for rf any general purpose rf transmitter-receiver pair would suffice. the ST12 combines the functionality of both encoder and decoder in a single package with several unique features for enhanced operation and a reduced component count for transmitter and receiver circuits. the enc-dec pin configures the ST12 ic for encode or decode operation automatically at power- up. 2. features encode / decode on single chip built in oscillator minimum external components wide operating voltage range. (2.0 - 5.5v) single chip encoding decoding mode 40khz carrier for infrared transmission medium 18 pin dip package 3. applications burglar alarm system smoke and fire alarm system garage door controllers car door controllers car alarm system security system cordless telephones other remote control systems
page 2 of 6 ? 2006 sunrom technologies http://www.sunrom.com 2 4. pin definitions pin number description 1-4 a0-a3 - 4 bit address input 5 gnd ? ground 6-13 d0-d7 ? 8 bit data input if configured as encoder d0-d7 ? 8 bit data output if configured as decoder 14 vcc - +5v dc 15 enc-dec ? configure chip as encoder or decoder encoder if pin is tied to vcc decoder if pin is tied to gnd 16 data rx-tx ? transmit data or receive data from this pin through ir/rf interface 17 latch-mom ? applicable in decoder mode latching output (toggle output) if pin is tied to vcc momentary output if pin is tied to gnd in encoder mode tie this pin to gnd or vcc and do not leave it floating 18 mode ir/rf ? selects transmit / receive by infrared or radio frequency ir mode if pin is tied to vcc rf mode if pin is tied to gnd encoder sends 40khz modulation signal in ir mode for driving ir led decoder inverts received data in ir mode 5. encoder when configured as encoder the chip will transmit signal containing 4 bit address a0-a4 and 8 bit of data d0-d7 from its data rx-tx pin. removing ground from a data input will end the transmission. infrared transmission will include data modulated for 40 khz frequency for driving infrared led. radio frequency transmission mode will transmit data in bi-phase manchester encoding. 5.1. latching key-press with the decoder in latch mode, data inputs d0-d7 of the encoder must be pressed & released one at a time to toggle decoder outputs on or off individually. multiple key presses are not allowed on the encoder when the decoder is configured for latch mode. 5.2. momentary key-press in momentary mode, any combination of the encoder data inputs d0-d7 may be grounded simultaneously. 6. decoder decoder outputs can sink or source up to 25ma per pin with a total combined device package maximum of 200ma allowing direct remote control of led?s, solid-state relays, and other logic devices without the need for secondary driver circuits.
page 3 of 6 ? 2006 sunrom technologies http://www.sunrom.com 3 7. data & address validation encoder address pins a0-a3 must be set to the same logic levels as decoder address pins a0-a3. if these do not match, the decoder will ignore data sent from the encoder. the decoder receives two consecutive & matching data/address packets before transferring data to the d0-d7 outputs. each 13-bit packet transmit time requires approximately 48ms. care should be taken not to violate these timing requirements when the ST12 is controlled by high-speed logic circuits or embedded controllers such as the pic, basic stamp or 8051. important: address input pins a0-a3 & configuration selection input must always be connected to vdd or circuit ground depending on the mode required. allowing any of these input pins to ?float? (leaving them un-connected) will cause erratic results. 8. transmitter application schematic (encoder) vcc u1 ST12 codec 5 14 15 4 16 17 18 1 2 3 6 7 8 9 10 11 12 13 gndvcc enc - dec a3 data rx - tx latch - mom mode ir - rf a0 a1 a2 d0 d1 d2 d3d4 d5 d6 d7 vcc ir sw4sw sw2sw q2 bc547 q1 bc547 9v battery cn1 sip2 1 2 u2stt-315 1 2 3 4 a n t g n d d a t a v c c d2 1n4007 c4 100n rf e1 antenna r110k sw8sw inout gnd u3 lm78l05 3 1 2 j1 jumper3p vcc 1001-34871 8 channel remote transmitter sunrom technologies http://www.sunrom.com 11 monday, may 01, 2006 title coderev date:sheet of c2 100n sw6sw vcc sw3sw vcc c1 100n sw1sw d1 ir led r2 4k7 sw5sw sw7sw rf vcc c3 100n ir
page 4 of 6 ? 2006 sunrom technologies http://www.sunrom.com 4 8.1. receiver application schematic (decoder) 9. related information infrared version of 8 channel rf remote control http://www.sunrom.com/product.php?id=114 o infrared led http://www.sunrom.com/product.php?id=118 o infrared detector tsop1738 http://www.sunrom.com/product.php?id=19 rf version of 8 channel rf remote control http://www.sunrom.com/product.php?id=115 o 315 mhz rf transmitter stt-315 http://www.sunrom.com/product.php?id=116 o 315 mhz rf receiver str-315 http://www.sunrom.com/product.php?id=117 ir receiver r1 10r j2 jumper3p u1 tsop1738 1 3 2 o u t g n d v c c rf out3 u4 ST12 codec 5 14 15 4 16 17 18 1 2 3 6 7 8 9 10 11 12 13 gndvcc enc - dec a3 data rx - tx latch - mom mode ir - rf a0 a1 a2 d0 d1 d2 d3d4 d5 d6 d7 out4 vcc vcc momentary out2 u2 str-315 1 2 3 4 5 6 7 8 a n t g n d g n d v c c ( 5 v ) v c c ( 5 v ) a n a l o g d a t a g n d e1 antenna c7 100n vcc vcc out7 ir c1 10uf 16v vcc out8 vcc j1 jumper3p out1 out6 latch c2 100n out5 vcc power supply inout gnd u5 78l05/to92 3 1 2 d10 c6 100n d12 led r2 1k c5 100n + c3 100uf 16v d11 + c4 100uf 16v vdd d13 d9 cn9 dc socket 12v input
page 5 of 6 ? 2006 sunrom technologies http://www.sunrom.com 5 10. electrical specifications paramater value maximum input/output sink/source current on any pin 25ma maximum input/output sink/source current total 200ma operating voltage 3.0-5.0v dc avg. no load operating current <2ma @5.0vdc carrier frequency / duty cycle +/- 2% 40khz / 50% 10.1. chip description the ST12 ? codec is available in a 18 pin dip package (0.3? width). it uses a supply voltage of 5v dc. outputs and inputs are ttl and cmos compatible. ST12 codec 5 14 15 4 16 17 18 1 2 3 6 7 8 9 10 11 12 13 gndvcc enc - dec a3 data rx - tx latch - mom mode ir - rf a0 a1 a2 d0 d1 d2 d3d4 d5 d6 d7 10.2. ordering information part number description 3000-1012 ST12 codec - ir/rf remote control encoder/decoder i.c.
page 6 of 6 ? 2006 sunrom technologies http://www.sunrom.com 6 11. disclaimer copyright ? sunrom technologies , 2006. version 1.0 - initial datasheet created april 2006 neither the whole nor any part of the information contained in, or the product described in this manual, may be adapted or reproduced in any material or electronic form without the prior written consent of the copyright holder. this product and its documentation are supplied on an as-is basis and no warranty as to their suitability for any particular purpose is either made or implied. sunrom technologies will not accept any claim for damages howsoever arising as a result of use or failure of this product. your statutory rights are not affected. this product or any variant of it is not intended for use in any medical appliance, device or system in which the failure of the product might reasonably be expected to result in personal injury. this document provides preliminary information that may be subject to change without notice. 12. contact sunrom technologies sunrom technologies 33, 1 st flr, yash niketan khokra circle, maninagar, ahmedabad - 380026, gujarat, india phone (+91) 9825 858 509 website url : http://www.sunrom.com/
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