PT2212 查看數據表（PDF） - Princeton Technology

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PT2212

Infrared Remote Control Transmitter

Princeton Technology 

Infrared Remote Control Transmitter

Tel: 886-2-66296288

Fax: 886-2-29174598

URL: http://www.princeton.com.tw

PT2212

KEY INPUT OPERATION

A Key Input Operation may be considered legal or illegal depending on the key pressed. For key

interconnection, please refer to the application circuit diagram in the APPLICATION CIRCUIT

SECTION.

A pull-down resistor is already connected in the VSS Terminals of the Key Input Pins. A 4x8 Key Matrix

which may be constructed by connecting Key Inputs – KI0 to KI3 and Key Scan Outputs – KO0 to KO7.

When more than two keys are pressed simultaneously, the transmission is terminated by the

multi-depression preventive circuit function. For conditions regarding the double key operation, please

refer to the DOUBLE KEY OPERATION SECTION.

If a key has been continuously pressed for a period of 36ms, the system code and the data code are

read and transmitted once. For ON Chattering prevention, the data reading is NOT performed when

the key is pressed during the first 9ms.

DOUBLE KEY OPERATION

As stated earlier, double key operation is possible for the following key combinations:

K21 and K22

K21 and K23

K21 and K24

K25 and K26

K25 and K27

K25 and K28

If other key combinations are pressed other than those stated above, then it is considered illegal

because of the PT2212’s multiple depression preventive circuitry. However, it is possible to inhibit this

multiple depression preventive circuitry so that a double key operation may be performed, thereby a

transmission can occur. This condition is possible if the D5 of the Data Code is set to “1”. Because of

the order of priority, a transmission can only be made possible in this mode by pressing K22~K24

(K26~K28) 126ms after pressing K21 (K25). Please refer to the diagrams below.

DOUBLE KEY TRANSMISSION TIMING

PT2212 V1.1

-5-

May, 2007

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