Description
HT-12D Decoder for Remote-Control Systems
The HT-12D is a decoder IC in the 212-series family for remote-control applications, including RF and infrared links. It is paired with a compatible 212-series encoder; the pair must use the same number of address bits and the same data format.
The HT-12D converts serial input into parallel outputs. It compares the received serial address with its local address three times continuously. The source says data is decoded when no error or unmatched code is found; a valid transmission is indicated by HIGH on VT. The 12-bit word comprises 8 address bits and 4 data bits. In the 4-bit latch-type output, data remains unchanged until new data is received.
See the HT-12E encoder listing.
Pin functions
| Pin | Function | Name |
|---|---|---|
| 1–8 | Eight address inputs | A0–A7 |
| 9 | Ground (0V) | GND |
| 10–13 | Four data/address outputs | D0–D3 |
| 14 | Serial data input | Input |
| 15 | Oscillator output | OSC2 |
| 16 | Oscillator input | OSC1 |
| 17 | Valid transmission, active high | VT |
| 18 | Supply; table lists 5V (2.4–12V) | VCC |
The supply entry in the source is ambiguous. Consult the seller-linked datasheet (PDF) to confirm the valid voltage range and oscillator requirements.
