INA200: INA200 COMPO goes high without any overcurrent condition

stefan faass

Prodigy 70 points

Part Number: INA200

When there is a rising edge on Signal #REST the Output CMPO goes high without any current through the shunt.

After this a high low high on Signal #REST will reset the Output CMPO.

But the next rising edge on Signal #REST the Output CMPO goes high again without any current.

VCC = 15VDC, Shunt = 5mR

over 6 years ago

0 kai klaas69 over 6 years ago

Guru 140200 points

Hi Stefan,

can you show us a schematic of your circuit?

Kai

0 stefan faass over 6 years ago in reply to kai klaas69

Prodigy 70 points

print5.tif

0 stefan faass over 6 years ago in reply to stefan faass

Prodigy 70 points

Oszi:
C3: = Reset
C2: = COMPO
In case when i set CMPI to gnd (R419 = not soldered and CMPI = GND) same Problem :-(

INA200(5) = uC Output
INA200(6) = uC Input

0 stefan faass over 6 years ago in reply to stefan faass

Prodigy 70 points

in case when #RESET = low , a overcurrent will be recognized correct.
Sometimes when #RESET = high, it works correct and a overcurrent will be recognized and latched correct.

0 kai klaas69 over 6 years ago in reply to stefan faass

Guru 140200 points

Hi Stefan,

Hhm, I cannot find a mistake. Looks like the IN200 is damaged. Can you ckeck the performance with a fresh INA200?

Kai

0 Patrick Simmons over 6 years ago in reply to stefan faass

TI__Mastermind 24165 points

Hello Stefan,

Thanks for considering to use Texas Instruments in your design. I would like to clarify, from looking at all of your posts I surmise you are seeing the device fail with and without over-current conditions. In the print5.tif, which of the above conditions does that correspond to? If it is of the condition in which there is a load and an over-current, could you get another oscilloscope shot with the over-current Vsense differential?

0 stefan faass over 6 years ago in reply to Patrick Simmons

Prodigy 70 points

print10.tif print11.tif print12.tif print13.tifHello Richard,

thanks for your reply

CH1: PIN3 CMPI

CH2: PIN6 COMPO

CH3: PIN5 #RESET

CH4: GLOBAL ERROR (Overcurrent IN200 and some other error condition)

print10,12,13 shows the wrong behavior of INA200

print11 shows the correct behavior of INA200

I changed C408 and C410 to bigger values -> without succes

I remove R419 -> without succes

I take another device -> without succes

But i have designed another HW with the same device

an it works ???? i am verry confused

0 stefan faass over 6 years ago in reply to stefan faass

Prodigy 70 points

Hello Patrick (sorry not Richard)

i have an additional Information. A colleaque of mine examined the other HW and what he find out is verry interesting.

We have the sam behavior of INA200. The first reset brings the COMPO to high and the second Pulse will reset the COMPO.

OSZI print scope_2: ch1: #RESET ch2: COMPO. The second pulse on reset is verry small

That means in Software i have a look at Signal COMPO and i bring multiple reset pules (high-low-high) until COMPO will go low ???

Is this the correct behaviour of the INA200

0 Patrick Simmons over 6 years ago in reply to stefan faass

TI__Mastermind 24165 points

Hello Stefan,

In section 7.3.3 we recommend putting a low pass filter on the reset pin when Vcc and Reset operate at different voltages. For larger differences between these voltages, we recommend longer rise times. Try incorporating an RC filter into your design with a 1us rise time. I think this may solve your issue.

0 stefan faass over 6 years ago in reply to Patrick Simmons

Prodigy 70 points

Hello Patrick,

now it works fine !

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

Amplifiers

Amplifiers forum

INA200: INA200 COMPO goes high without any overcurrent condition