Holtek Semiconductor Inc HT12D, HT12F Datasheet

Features

Operating voltage: 2.4V~12V

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Low power and high noise immunity CMOS

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technology
Low standby current

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Capable of decoding 12 bits of information

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Pair with Holtek¢s212series of encoders

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Binary address setting

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Received codes are checked 3 times

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Applications

Burglar alarm system

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Smoke and fire alarm system

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Garage door controllers

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Car door controllers

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General Description

The 212decoders are a series of CMOS LSIs for
remote control system applications. They are
paired with Holtek¢s2
fer to the encoder/decoder cross reference ta­ble). For proper operation, a pair of
encoder/decoder with the same number of ad­dresses and data format should be chosen.

The decoders receive serial addresses and data
from a programmed 2
are transmitted by a carrier using an RF or an
IR transmission medium. They compare the se­rial input data three times continuously with

12

series of encoders (re-

12

series of encoders that

12

2

Series of Decoders

Address/Data number combination

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HT12D: 8 address bits and 4 data bits

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HT12F: 12 address bits only

Built-in oscillator needs only 5% resistor

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Valid transmission indicator

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Easy interface with an RF or an infrared

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transmission medium
Minimal external components

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Car alarm system

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Security system

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Cordless telephones

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Other remote control systems

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their local addresses. If no error or unmatched
codes are found, the input data codes are de
coded and then transferred to the output pins.
The VT pin also goes high to indicate a valid
transmission.

12

The 2
ing informations that consist of N bits of ad­dress and 12-N bits of data. Of this series, the
HT12D is arranged to provide 8 address bits
and 4 data bits, and HT12F is used to decode 12
bits of address information.

series of decoders are capable of decod-

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Selection Table

Function

Part No. No. Type

HT12D 8 4 L

HT12F 12 0

Notes: Data type: L stands for latch type data output.

VT can be used as a momentary data output.

Address

No.

Data

¾Ö

VT Oscillator Trigger Package

RC oscillator

Ö

RC oscillator

1 July 12, 1999

DIN active ²Hi²
DIN active ²Hi²

18 DIP/20 SOP

18 DIP/20 SOP

Block Diagram

212Series of Decoders

OSC1OSC2

D ivider

D a ta D e te c to r

C om parator C om parator

Address

D ata Shift

R egister

VDD VSS

Latch C ircuit

C ontrol Logic

Buffer T ra n s m is s io n G a te C irc u it

Data

VT

DIN

O scillator

Buffer

S y n c . D e te c to r

Note: The address/data pins are available in various combinations (see the address/data table).

Pin Assignment

VDD

VT

OSC1

OSC2

DIN

A11

A10

A9

A8

12-A ddress
0 -D a ta

NC

1

A0

2

A1

3

A2

4

A3

5

A4

6

A5

7

A6

8

A7

9

VSS

10

HT12F

2 0 S O P

20

NC

19

VDD

18

VT

17

OSC1

16

OSC2

15

DIN

14

A11

13

A10

12

A9

11

A8

8-A ddress
4-D ata

1

A0

2

A1

3

A2

4

A3

5

A4

6

A5

7

A6

8

A7

9

VSS

H T12D

18 D IP

8-A ddress
4-D ata

NC

18

VDD

17

VT

16

OSC1

15

OSC2

14

DIN

13

D11

12

D10

11

D9

10

D8

A0

A1

A2

A3

A4

A5

A6

A7

VSS

1

2

3

4

5

6

7

8

9

10

20

NC

19

VDD

18

VT

17

OSC1

16

OSC2

15

DIN

14

D11

13

D10

12

D9

11

D8

HT12D
2 0 S O P

12-A ddress
0 -D a ta

1

A0

2

A1

3

A2

4

A3

5

A4

6

A5

7

A6

8

A7

9

VSS

H T12F

18 D IP

18

17

16

15

14

13

12

11

10

2 July 12, 1999

Pin Description

212Series of Decoders

Pin Name I/O

A0~A11 I

Internal

Connection

NMOS

TRANSMISSION

GATE

Description

Input pins for address A0~A11 setting
They can be externally set to VDD or VSS.

D8~D11 O CMOS OUT Output data pins

DIN I CMOS IN Serial data input pin

VT O CMOS OUT Valid transmission, active high

OSC1 I OSCILLATOR Oscillator input pin

OSC2 O OSCILLATOR Oscillator output pin

VSS I

VDD I

¾
¾

Negative power supply (GND)

Positive power supply

Approximate internal connection circuits

NMOS

TRANSM ISSION

GATE

CMOS OUT

C M O S IN

EN

OSC1

O S C ILLA TO R

OSC2

Absolute Maximum Ratings

Supply Voltage...............................-0.3V to 13V

Input Voltage....................V

-0.3 to VDD+0.3V

SS

Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maxi

mum Ratings² may cause substantial damage to the device. Functional operation of this de
vice at other conditions beyond those listed in the specification is not implied and prolonged
exposure to extreme conditions may affect device reliability.

Storage Temperature.................-50°Cto125°C

Operating Temperature ..............-20°Cto75°C

3 July 12, 1999

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