Electrical – Encoder ICs replaces shift registers?


Sorry in advance am a kid or below that in electronics. On learning about shift registers (Eg:74hc165 input shift register) and encoder, decoder ICs (HT12D, HT12E). I really got a similarity between HT12E and 74HC165 input shift register. According to their explanation 74HC165 can convert 8 parallel input into serial output.

HT12E can convert 12bit (including address bits) to serial output. So really getting confused what is the difference between encoders and so called shift registers. Both sounds same for a beginner. Anyone please explain the difference.

Best Answer

The HT12E is a lot more than just a shift register. It 'encodes' the bits into a series of pulses which are designed to be transmitted over a wireless link (Infrared or RF) and 'decoded' by the HT12D.

The link may not support DC signal levels and is inherently noisy, so the HT12E converts the bits into Manchester code which has no DC bias, repeats each bit sequence at least four times so the receiver can reject errors, and prepends pilot and sync pulses so the receiver can lock onto the start of each transmission.

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