HT640

The HT640 has the following features including Operating voltage: 2.4V~12V;Low power and high noise immunity CMOS technology;Low standby current;Capable of decoding 18 bits of information;Pairs with HOLTEK's HT640 encoder;10 address pins; 8 data pins;Trinary address setting;Two times of receiving check;Built-in oscillator needs only a 5% resistor;Valid transmission indictor;Easily interface with an RF or an infrared transmission medium;Minimal external components.

The HT640 encoder is a CMOS LSI for remote control system applications. It is paired with the HT658 decoder. The HT640 encoder is capable of encoding 18 bits of information, which consists of 10 address bits and 8 data bits. The programmable address / data is transmitted together with the header bits via an RF or an infrared transmission medium upon receipt of a trigger signal on the TE line.This product is manufactured and supported by Holtek Semiconductor. This data sheet is provided as a courtesy to Linx customers and is believed to be accurate at the time of publication, however these specifications may change at any time without notice. Linx Technologies makes no representation as to the accuracy or suitability of this information for any purpose. Stresses above those listed under"Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only. Functional operation of this device at these or any other conditions above those indicated in the operational sections of this specification is not implied and exposure to absolute maximum rating conditions for extened periods may affect device reliability.

The HT640 encoder begins a three-word transmission cycle when the transmission enable line (TE) is pulled high. This cycle will repeat itself as long as the TE line is held high. Once TE falls low, the encoder output completes its final cycle and then stops as shown in the Encoder/Decoder Timing diagram. When a transmission enable signal is applied, the encoder scans and transmits the status of the 18 bits of address/data serially in the order A0 to A9,D0 to D7.