Basic Information

• Question 1
  How to match the oscillating frequencies of the 3¹⁸ encoders and decoders?
• Question 2
  How to use the three-state Address pins of the 3¹⁸ series?
• Question 3
  How to use the Holtek MCU to implement the remote decoder function?

Question 1

How to match the oscillating frequencies of the 3¹⁸ encoders and decoders?

Answer

For 3¹⁸ series, the oscillating realations between encoders and decoders are : 
fosc (HT604L/HT614/HT692 decoder) = fosc (HT600/HT680/HT6207 encoder) 

If the HT600 is used as encoder, a typical 100kHz oscillating frequency is recommended. The decoder device can be either HT604L or HT614 whose decoder oscillating frequency is typically same as the encoders, namely 100kHz. In the Oscillator Frequency/Supply Voltage graph in the HT600/HT680/HT6207 datasheet, take 5V application for example and the typical 100kHz oscillating frequency, a 330Kohm resistor is therefore selected. In the Oscillator Frequency/Supply Voltage graph in the HT604L/HT614/HT692 datasheet, take 5V and the 100kHz and the resistor will be around 300Kohm. Note that user can choose other resistor values as long as the frequency relation is kept and the decoder frequency is under 300kHz, otherwise it might result in decoding failure.

Question 2

How to use the three-state Address pins of the 3¹⁸ series?

Answer

For the 3¹⁸ series, the Address pins are CMOS Transmission Gates internally. The Address pins can be connected to VDD, VSS or left open. If the Address pin is connected to VDD, Dout will have data 1 waveform; If the Address pin is connected to VSS, Dout will have data 0 waveform; If the Address pin is left open, Dout will have 3^rd state data waveform.

Question 3

How to use the Holtek MCU to implement the remote decoder function?

Answer

Please refer to the relevant example code in "Application Notes" under the "Technical Support" section of our company web site.

Application Description

• Question 1
  How can I match correct pairs of devices for the 3^18 Encoder/Decoders?

Question 1

How can I match correct pairs of devices for the 3^18 Encoder/Decoders?

Answer

The 3^18 Encoder series contains the HT600/HT680/HT6207 devices while the Decoder series contains the HT604L/HT614/HT692 devices, they are matched as shown in the following table: