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Analog Switch- what will happen if there is no clk in?

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JimLo

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http://www.supertex.com/pdf/datasheets/HV219.pdf

Please look at the datasheet of analog-switch HV219 from SuperTex.

could i put a static logical voltage in Data_in to get the switch-on.
and ground the Data_in pin to make it switch-off.

besides, what is the simplest signal to be put in the CLK input? could i leave it unconnected?


thank you dear engineers.
 

IanP

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To control switches in the HV219 IC you have to clock-in a word consisting of 8 bits; each bit is responsible for one output: bit value H => output switch closed, bit value L => switch open ..
In other words, you have to generate 8 clock pulses and simultaneously feed 8 data bits to the Din pin ..
After all bits are clocked-in to the internal shift register, you have to generate a pulse H-->L-->H on the CL pin; this will latch the data bits in the ouput latches ..

To keep outputs active, the CL pin has to be kept L(ow) ..

As you can see the operation of activation/disactivation of one (or more) of the eight switches will require some logic, and one way of doing this will be to employ a microcontroller ..
A single microcontroller can control 1 (8 switches), 2 (16 switches), 3(24), or more of the HV219 ICs ..

Regards,
IanP
 

    JimLo

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JimLo

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IanP said:
To control switches in the HV219 IC you have to clock-in a word consisting of 8 bits; each bit is responsible for one output: bit value H => output switch closed, bit value L => switch open ..
In other words, you have to generate 8 clock pulses and simultaneously feed 8 data bits to the Din pin ..
After all bits are clocked-in to the internal shift register, you have to generate a pulse H-->L-->H on the CL pin; this will latch the data bits in the ouput latches ..

To keep outputs active, the CL pin has to be kept L(ow) ..

As you can see the operation of activation/disactivation of one (or more) of the eight switches will require some logic, and one way of doing this will be to employ a microcontroller ..
A single microcontroller can control 1 (8 switches), 2 (16 switches), 3(24), or more of the HV219 ICs ..

Regards,
IanP
thank you very much, my friend !

after spending a whole day searching on the internet, i guess i have finally found the simplest solution for my project...

HV20822 is the right switch for me.!!!
 

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