Need Help for LTC7004

Hi,

We are using above circuit for 48V load ON/OFF control

We are facing one problem if i am enable INP pin through micro controller i got 48V as output

If i am disable INP i got 11.5V as ouput.

But i am connecting 10K resistor on MOSFET sorce  side with respect to GND,now i got 0V as output

Why i am getting 11.5V floating voltage as ouput??

I can't understand below point in datasheet,Can you explain it? 

TS (Pin 8):Top (High Side) source connection or GND if
used in ground referenced applications 

Can you give me solution for above points?

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  • 0
    •  Analog Employees 
    on Jan 20, 2018 5:51 AM

    The LTC7004's internal charge pump supplies current out of the BST pin to charge/maintain voltage on the BST-TS capacitor. This small current is likely why you are seeing the TS pin float to 11.5V when TS is unloaded. 

     

    The Pin Function description "TS (Pin 8): Top (High Side) source connection or GND if used in ground referenced applications" on page 6 of the LTC7004 Data Sheet means that the TS pin is (typically) connected to the source the external MOSFET in high-side applications or to GND in ground referenced (low side applications) applications. Low side applications are when you are using the LTC7004 to drive a low side (source connected to GND) MOSFET.

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  • 0
    •  Analog Employees 
    on Jan 20, 2018 5:51 AM

    The LTC7004's internal charge pump supplies current out of the BST pin to charge/maintain voltage on the BST-TS capacitor. This small current is likely why you are seeing the TS pin float to 11.5V when TS is unloaded. 

     

    The Pin Function description "TS (Pin 8): Top (High Side) source connection or GND if used in ground referenced applications" on page 6 of the LTC7004 Data Sheet means that the TS pin is (typically) connected to the source the external MOSFET in high-side applications or to GND in ground referenced (low side applications) applications. Low side applications are when you are using the LTC7004 to drive a low side (source connected to GND) MOSFET.

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