Plastic Remote Control 33 keys for Hathway digital / LRIPL/ Solid set top box/ Jio set top box
At present, as a one-way infrared communication technology, infrared remote control is widely used in national defense, industrial production, household appliances, security and people's daily life because of its stable performance, low power consumption, fast speed, convenient use and low cost.
The design of infrared remote control coding chip with low cost, low power consumption, multi-function and high stability has become a key development direction of infrared remote control technology. This topic designs an infrared remote control coding chip specially used for infrared remote control transmission system, which adopts NEC coding format.
Its transmission code includes pilot code, 16 bit client code, 8-bit key code and 8-bit key code inverse code, and is transmitted after being modulated by 38kHz carrier signal. The chip uses a single leg quartz crystal oscillator, which integrates the resistance and capacitance in the chip. Compared with the traditional infrared remote control coding chip, it saves one pad and two capacitors in the peripheral circuit; At the same time, a low-frequency ring oscillator is built in the chip to provide a low-frequency key scanning clock to the key scanning circuit when the system is in standby, effectively reducing the standby power consumption of the transmission system; The design of the key scanning input and output circuit realizes the multi-purpose of one pin of the chip. Only 12 pin jumpers can realize 66 key functions, reducing the number of chip pins and the packaging cost of the chip; The customer code of the chip is stored in the internal mask ROM, and the code selection of 16 bit customer code can be realized through the direct jumper between the CSS pin and the key input / output pin. The CSS terminal has a built-in pull-up resistor, and the external circuit does not need a pull-up resistor and a jumper diode; The infrared remote control transmission system designed with this chip has stable performance, less peripheral components, simple circuit, low cost and is convenient for production and processing