LM5066I: Vout > Vin when using PI-Commander

Hi Penny,

Welcome to E2E !!!

This 16 mV difference might be due to mismatches in the DIRECT format calculation algorithms implemented in the PI commander GUI. It's requested that you ignore this difference. 

Hi Avishek 

How much (tolerance) can I ignore for Vin, Vout, Iin, Pin?

I measured by meter and read value from GUI.

I found the tolerance of current up to 6%.

Thanks!

Penny

Hi Penny,

Please see the telemetry accuracy below. 

Hi Avishek

Our spec: 54V, 11.11A (max) 

I compared the value by Meter and GUI. the result is out of spec.

And, the accuracy of Table 1 and Electrical Characteristics is different.

Thanks!

Penny

Hi Penny,

What is the current limit threshold? GUI conversion depends on the RSNS value. Have you measured the value of RSNS on the PCB? You can put in an accurate 10 A of load current, measure the differential voltage across the VIN_K and SENSE pins using a digital multimeter, and find out the exact value of RSNS seen by the device.

Hi Avishek

Here is configuration, is anyelse impact the accurary?

Thanks!

Penny

Hi Penny,

As I said in the earlier post, theoretically, RSNS is 1.5 mΩ. But how much is on the PCN seen by VIN_K and SENSE pins? This is important. Please measure. 

Hi Avlshek

Update the latest measurement, I change the measure point and get good result.

But the accuracy is not well on light-load, 0.555A and 1.11A.  (Rsns = 0.75m Ohm, Rsns is changed)

is it reasonable?

0.555A: Voltage between VIN_K and SENSE is 0.4305mV ==> Iin = 0.574A, the accuracy is 12.2%

1.111A: Voltage between VIN_K and SENSE is 0.8555mV ==> Iin = 1.14A, the accuracy is 5.41%

Is my understanding correct?

1. Rsns = 1.5mOhm

 2. Rsns = 0.75mOhm

I found IINACC will be around 12% when current is 0.555A. how to know it is reasonable?

Thanks!