HT12D 12-Bit Decoder IC DIP-18

HT12D 12-Bit Decoder IC DIP-18 is a CMOS LSI series peripheral for remote control system applications that integrates seamlessly with the HT12E encoder to form a complete wireless data link. This versatile decoder receives serial addresses and data from a programmed 2¹² series encoder and compares them with its local address. Consequently, the IC effectively prevents unauthorized triggering by ensuring the received address match the local address pins. Utilizing a wide operating voltage range and low power consumption, the HT12D decodes 8 bits of address and 4 bits of data. Furthermore, the built-in oscillator requires only an external resistor to set the operating frequency. Therefore, you should choose the HT12D for cost-effective RF or infrared remote control projects that demand high reliability and simple integration.

Key Features:

• 2¹² Series Decoding: The IC decodes up to 12 bits of information, typically split into 8 address bits and 4 data bits.
• Low Standby Current: Designed with CMOS technology, this device consumes minimal power, which extends the battery life of portable receiving units.
• Built-in Oscillator: Users can easily configure the internal oscillator by connecting a single external resistor between the OSC1 and OSC2 pins.
• Valid Transmission Indicator: The VT (Valid Transmission) pin goes high to signal a successful match of address and data from the encoder.
• Noise Immunity: This decoder employs a double-check algorithm that requires two consecutive successful bit-matching cycles before updating the output.

Technical Specifications:

• Operating Voltage (V_DD): 2.4 V to 12.0 V
• Standby Current: ≈ 0.1 μA at V_DD = 5 V
• Number of Address Pins: 8 Pins (A0 – A7)
• Number of Data Pins: 4 Pins (D8 – D11)
• Oscillator Frequency: ≈ 150 kHz (at 5 V with a 51 kΩ resistor)
• Output Type: CMOS Output
• Operating Temperature: −20°C to +75°C

Mechanical Specifications:

• Package Style: DIP-18 (Dual In-line Package)
• Lead Count: 18 Pins
• Encapsulation: Plastic (Molded)
• Mounting Type: Through-hole (THT)

Dimensions:

• Body Length: ≈ 22.86 mm
• Body Width: ≈ 6.35 mm
• Pin Pitch: 2.54 mm
• Row Spacing: 7.62 mm (0.3 inch)

Pinout and Wiring:

• Pins 1 to 8 (A0 – A7): Address inputs. These must match the address settings on the HT12E encoder.
• Pin 9 (V_SS): Connect this pin to the circuit ground (0 V).
• Pins 10 to 13 (AD8 – AD11): Data output pins that reflect the 4 bits of data sent by the transmitter.
• Pin 14 (DIN): Serial data input pin. Connect this to the output of your RF receiver or IR sensor.
• Pin 15 & 16 (OSC2 & OSC1): Oscillator pins. Connect a resistor (typically 51 kΩ for 5 V operation) across these pins.
• Pin 17 (VT): Valid Transmission pin. This pin drives high when the decoder identifies a valid signal with a matching address.
• Pin 18 (V_DD): Connect to the positive power supply (2.4 V to 12 V).

Datasheet Reference:

• Download Holtek HT12D 12-Bit Decoder Datasheet

Commonly Used in:

• RF Remote Systems: Decoding 433 MHz or 315 MHz wireless signals for garage door openers and gate controllers.
• Infrared (IR) Links: Providing secure data transmission for short-range line-of-sight communication.
• Security Systems: Serving as the primary interface for wireless alarm triggers and door sensors.

Applications:

• Wireless Automation: Controlling home appliances or industrial machinery from a distance.
• Remote Keyless Entry: Implementing basic secure entry for vehicles or restricted storage areas.
• Toy Controllers: Building reliable wireless links for remote-controlled cars and robots.
• Smart Home Integration: Acting as a bridge between wireless sensors and central control units.

Equivalent Models:

• HT12F: A similar decoder that focuses on decoding 12 bits of address rather than a mix of address and data.
• PT2272: A popular alternative decoder from Princeton Technology that often serves as a direct substitute in RF modules.
• SC2272: Another widely used 2¹² decoder that maintains pin compatibility and functional parity with the HT12D series.

Package Includes:

• 1 x HT12D 12-Bit Decoder IC DIP-18