Pack of 2 M708B1 | PCM Remote Control Transmitter IC | VDD 4.5 V to 10.5 V | STMicroelectronics | DIP20 Housing

Description

This IC has been developed for remote control in consumer applications. It uses a highly reliable transmission code which has the capacity of 1024 channels. Each transmitted word is structured into 4 bits which constitute the address and 6 bits which constitute the command. However only 2 addresses and 30 commands are available in this IC. An additional command (00000) is used to transmit the "end of transmission code" when the key is released. Additional bits are transmitted for synchronization of transmitter and receiver clocks and for security checks. The address organization provides simultaneous applications without interference among each system. The receiver accepts the decoded command only if the transmitted address matches the address se- lected at the receiver. Four addresses are available for this purpose. The reference oscillator is controlled by a cheap ceramic resonator. When the M708 works in conjunction with M490/M491 single chip station memory and H.C. Receiver the oscillator frequency can be in the range 445 to 510 kHz and no synchronization is required with the receiver clock. The M708 is produced with CMOS Si-gate technol- ogy and is available in a 20-pin dual in-line plastic package. 30 CHANNELS / 4 ADDRESSES Selectable flash/carrier transmission mode. End of transmission code. Very low power dissipation through transmission: DUTY CYCLE 0.15% (flash mode), 0.7% (carrier mode). Single contact matrix keyboard. Integrated anti-bounce and interlock. Wide Supply Range (M708 4.5 to 10.5 V) / (M708A 3 to 10.5 v). Wide frequency range (445 to 510 kHz ceramic resonator). 20 pin plastic packaging. To be used in conjunction with M490/M491 single chip station memory and R.C. Receiver (flash mode) on with microprocessor control system (carrier mode).