HV9821 LED driver current sense resistor conenction is wrong?

Status
Not open for further replies.
T

treez

Guest
On page 3 of the HV9821 LED driver datasheet, howcome on page 3, the high side current sense resistor is connected to ground?

HV9821
**broken link removed**

So there could be 700V one side of this resistor, and then ground on the other side of this resistor?
 

the high side current sense resistor is connected to ground?
Click to expand...
I don't see a ground connection of Rs.
 
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
on the "functional block diagram...inside the controller there is a ground symbol.
 

But the IC hasn't a ground pin. The block diagram clarifies that the ground symbol refers to the OUT pin.
 
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
But the IC hasn't a ground pin. The block diagram clarifies that the ground symbol refers to the OUT pin.
Click to expand...

I agree, but why is the Rs connected to it?
 

Output current is sensed at the OUT pin, I think. So what's strange about it?
 
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
The buck freewheel diode cathode is grounded in their diagram
Click to expand...
May be I didn't yet get your point, but the diode connection is also typical for a buck converter.
 
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
I really don't get your point. :?:

Very regularly, the cathode is grounded. The anode is not grounded.

 
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
but your picture shows the anode of D1 directly connected to ground , as it should be.

If you open out that picture above, you would see the cathode of D1 has got a ground connection , which it shouldnt have.
 

You are confusing the substrate connection inside the chip with a ground connection. See my post #4.
 
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…