HT12A/HT12E - 212 Series of Encoders - Farnell

1 ht12a /HT12E212 Series of EncodersSelection No. Oscillator TriggerCarrierOutputNegativePolarityPack agePart ~D1138kHzNo18 DIP, 20 SOPHT12E840 RCoscillatorTENoNo18 DIP, 20 SOPNote:Address/Data represents pins that can be either address or data according to the application 20, 2009 General DescriptionThe 212encoders are a Series of CMOS LSIs for remotecontrol system applications. They are capable of encod-ing information which consists of N address bits and12-N data bits. Each address/data input can be set toone of the two logic states.

2 The programmed ad-dresses/data are transmitted together with the headerbits via an RF or an infrared transmission medium uponreceipt of a trigger signal. The capability to select a TEtrigger on the ht12e or a DATA trigger on the HT12 Afurther enhances the application flexibility of the 212se-ries of Encoders . TheHT12A additionally provides a38kHz carrier for infrared Operating ~5V for the ~12V for the ht12e Low power and high noise immunity CMOS technology Low standby current: (typ.) at VDD=5V ht12a with a 38kHz carrier for infrared transmissionmedium Minimum transmission word-Four words for the ht12e -One word for the ht12a Built-in oscillator needs only 5% resistor Data code has positive polarity Minimal external components Pair with Holtek s212series of decoders 18-pin DIP.

3 20-pin SOP packageApplications Burglar alarm system Smoke and fire alarm system Garage door controllers Car door controllers Car alarm system Security system Cordless telephones Other remote control systemsBlock DiagramTETriggerHT12 EDATA TriggerHT12 ANote:The address data pins are available in various combinations (refer to the address/data table).Pin AssignmentHT12A/HT12 ERev. 20, 2009 Oscillator 3 DividerOSC1 OSC2 VDDVSS12 TransmissionGate Circuit 12 Counter &1 of 12 DecoderBinary DetectorTEA0A7 DOUTData Select& 576 DividerVDDVSS12 TransmissionGate Circuit 12 Counter &1 of 12 DecoderBinary DetectorDOUTData Select& 18 DIP-AHT12A 20 SOP-A8-Address4-Address/DataA0A1A2A3A4A5 A6A7 VSSVDDDOUTOSC1 OSC2 TEAD11AD10AD9AD8123456789181716151413121 110 ht12e 18 DIP-A8-Address4-Address/Data123456789102 0191817161514131211 NCVDDDOUTOSC1 OSC2 TEAD11AD10AD9AD8 NCA0A1A2A3A4A5A6A7 VSS ht12e 20 SOP-APin DescriptionPin

4 NameI/OInternalConnectionDescriptionA0~A 7 ICMOS IN Pull-high( ht12a )Input pins for address A0~A7 settingThese pins can be externally set to VSS or left openNMOS TRANSMISSIONGATE PROTECTIONDIODE ( ht12e )AD8~AD11 INMOS TRANSMISSIONGATE PROTECTIONDIODE ( ht12e )Input pins for address/data AD8~AD11 settingThese pins can be externally set to VSS or left openD8~D11 ICMOS IN Pull-highInput pins for data D8~D11 setting and transmission enable, activelowThese pins should be externally set to VSS or left open (see Note)DOUTOCMOS OUTE ncoder data serial transmission outputL/MICMOS IN Pull-highLatch/Momentary transmission format selection pin:Latch: Floating or VDDM omentary: VSSTEICMOS IN Pull-highTransmission enable, active low (see Note)OSC1 IOSCILLATOR 1 Oscillator input pinOSC2 OOSCILLATOR 1 Oscillator output pinX1 IOSCILLATOR 2455kHz resonator oscillator inputX2 OOSCILLATOR 2455kHz resonator oscillator outputVSSI Negative power supply, groundVDDI Positive power supplyNote.

5 D8~D11 are all data input and transmission enable pins of the a transmission enable pin of the Internal ConnectionsHT12A/HT12 ERev. 20, 2009 NMOSTRANSMISSIONGATECMOS INPull-highCMOS OUTOSCILLATOR 1 OSC2 OSC1 OSCILLATOR 2X1X2 ENNMOS TRANSMISSION GATEPROTECTION DIODEVDDA bsolute Maximum RatingsSupply Voltage ( ht12a ) .. to VSS+ Voltage ( ht12e ) .. to 13 VInput Voltage .. to VDD+ Temperature ..-50 Cto125 COperating Temperature ..-20 Cto75 CNote: These are stress ratings only. Stresses exceeding the range specified under Absolute Maximum Ratings maycause substantial damage to the device.

6 Functional operation of this device at other conditions beyond thoselisted in the specification is not implied and prolonged exposure to extreme conditions may affect device CharacteristicsHT12 ATa=25 CSymbolParameterTest Voltage Current3 VOscillator stops Current3 VNo loadfOSC=455kHz 200400mA5V 400800mAIDOUTO utput Drive Current5 VVOH= (Source) mAVOL= (Sink) mAVIH H Input Voltage VDDVVIL L Input Voltage 0 ~D11 Pull-highResistance5 VVDATA=0V 150300kWHT12 ETa=25 CSymbolParameterTest Voltage Current3 VOscillator stops 24mAIDDO perating Current3 VNo load, fOSC=3kHz 4080mA12V 150300mAIDOUTO utput Drive Current5 VVOH= (Source) mAVOL= (Sink)

7 MAVIH H Input Voltage VDDVVIL L Input Voltage 0 Frequency5 VROSC= 3 kHzRTETEPull-high Resistance5 VVTE=0V 20, 2009 Functional DescriptionOperationThe 212series of Encoders begin a 4-word transmission cycle upon receipt of a transmission enable (TEfor the HT12 Eor D8~D11 for the ht12a , active low). This cycle will repeat itself as long as the transmission enable (TEor D8~D11) isheld low. Once the transmission enable returns high the encoder output completes its final cycle and then stops asshown WordIf L/M=1 the device is in the latch mode (for use with the latch type of data decoders).

8 When the transmission enable is re-moved during a transmission, the DOUT pin outputs a complete word and then stops. On the other hand, if L/M=0 the de-vice is in the momentary mode (for use with the momentary type of data decoders). When the transmission enable isremoved during a transmission, the DOUT outputs a complete word and then adds 7 words all with the 1 data information word consists of 4 periods as illustrated 20, 20094 words4 wordsEncoderDOUTT ransmittedContinuously< 1 wordTE Transmission timing for the HT12 EEncoderDOUTT ransmittedContinuously< 1 wordD8~D11 Key-in 1 wordwith 38kHz carrier1 wordTransmission timing for the ht12a (L/M=Floating or VDD)EncoderDOUTT ransmittedContinuouslyD8~D11 Key-in 1 word< 1 word7 words1 word7 words(all data=1)

9 (all data=1)Transmission timing for the ht12a (L/M=VSS)1/3 bit sync. periodpilot period (12 bits)address code period period data code Composition of informationAddress/Data WaveformEach programmable address/data pin can be externally set to one of the following two logic states as shown address/data bits of the ht12a are transmitted with a 38kHz carrier for infrared remote controller Programming (Preset)The status of each address/data pin can be individually pre-set to logic high or low . If a transmission-enable signalis applied, the encoder scans and transmits the status of the 12 bits of address/data serially in the order A0 to AD11 forthe ht12e encoder and A0 to D11 for the ht12a information transmission these bits are transmitted with a preceding synchronization bit.

10 If the trigger signal isnot applied, the chip enters the standby mode and consumes a reduced current of less than 1mA for a supply voltage applications preset the address pins with individual security codes using DIP switches or PCB wiring, while thedata is selected by push buttons or electronic following figure shows an application using the ht12e : ht12a /HT12 ERev. 20, 2009"One""Zero"fOSCA ddress/Data BitAddress/Data bit waveform for the ht12e "One""Zero"fOSCData BitData Bit"One""Zero"Address BitAddress Bit38kHzcarrierAddress/Data bit waveform for the HT12 ATEVDDA0A1A2A3A4A5A6A7 VSSAD8AD9AD10AD11 OSC1 OSC2 DOUTT ransmissionmediumVDDVSSThe transmitted information is as shown.