NTE7233 Integrated Circuit 12 2 CMOS LSI Encoder for Remote Control Systems Description: The NTE7233 is a 212 CMOS LSI encoder in an 18−Lead DIP type package for use in remote control system applications. For proper operation, the NTE7233 should be paired with the NTE7232 decoder or similar device with the same number of addresses and data format. The NTE7233 is capable of encoding information which consists of N address bits and 12−N data bits. each address/data input can be set to one of the two logic states. The programmed addresses/data are transmitted together with the header bits via an RF or an infrared transmission medium upon receipt of a trigger signal. Features: D Operating Voltage: 2.4V to 12V D Low Power and High Noise Immunity CMOS Technology D Low Standby Current D D D D One Word Minimum Transmission Built−In Oscillator Needs Only 5% Resistor Data Code has Positive Polarity Minimal External Components Features: D Burglar Alarm Systems D Smoke and Fire Alarm Systems D Garage Door Controllers D Car Door Controllers D D D D Car Alarm Systems Security Systems Cordless Telephones Other Remote Control Systems Absolute Maximum Ratings: (Note 1) Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3V to 13V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VSS−0.3 to VDD+0.3V Operating Temperature Range, Topr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −205 to +755C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −505 to +1255C Note 1. These are stress ratings only. Stresses exceeding the range specified under “Absolute Maximum Ratings” may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in this specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Electrical Characteristics: (VDD = 5V, TA = +255C unless otherwise specified) Parameter Symbol Operating Voltage VDD Standby Current ISTB Test Conditions VDD = 3V VDD = 12V Operating Current IDD VDD = 3V VDD = 12V Min Typ Max Unit 2.4 5.0 12 V Oscillator Stops − 0.1 1.0 A − 2 4 A No Load, fOSC = 150kHz − 40 80 A − 150 300 A Data Output Source Current ID VOH = 0.9V −1.0 −1.6 − mA Data Output Sink Current ID VOL = 0.1V 1.0 1.6 − mA “H” Input Voltage VIH 0.8VDD − VDD V “L” Input Voltage VIL 0 − 0.2VDD V Oscillator Frequency fOSC ROSC = 1.1M5 − 3 − kHz TE Pull−High Frequency RTE VTE = 0V − 1.5 3.0 M5 Functional Description: Operation The NTE7233 encoder begins a 4−word transmission cycle upon receipt of a transmission enable (TE). This cycle will repeat itself as long as the transmission enable (TE) is held low. One the transmission enable returns high the encoder output completes its final cycle and then stops. Information Word If L/M=1 the device is in the latch mode (for use with the latch type of data decoders). When the transmission enable is removed during a transmission, the DOUT pin outputs a complete word and then stops. On the other hand, if L/M=0 the device is in the momentary mode (for use with the momentary type of data decoders). When the transmission enable is removed during a transmission, the DOUT outputs a complete word and then adds 7 words all with the “1” data code. Address/Data Programming (Preset) The status of each address/data pin can be individually pre−set to logic “high” or “low”. If a transmission−enable signal is applied, th encoder scans and transmits the status of the 12 bits of address/data serially in the order A0 to AD11. During information transmission these bits are transmitted with a preceding synchronization bit. If the trigger signal is not applied, the chip enters the standby mode and consumes reduced current of less than 1 A for a supply voltage of 5V. Usual applications preset the address pins wit individual security codes using DIP switches or PCB wiring, while the data is selected by push buttons or electronic switches. Transmission Enable Transmission is enabled by applying a low signal to the TE pin. Pin Connection Diagram A0 1 A1 2 A2 3 18 VDD A3 4 15 OSC2 A4 5 14 TE A5 6 13 AD11 A6 7 12 AD10 A7 8 11 AD9 10 AD8 17 DOUT 16 OSC1 VSS 9 18 10 1 9 .920 (23.4) Max .260 (6.6) .155 (3.94) .100 (2.54) .115 (2.9) Min .430 (10.9) Max