INA226: Resistor burned

Hailiang Zhang

Part Number: INA226

Hi Team,

Could you pls help review the schematic? CB and CP are connected to Rshut, and the voltage is 75mV. Customers report that R42 and R51 will burn out, the ratio is 1%. The specifications of R51 and R42 are 10 ohms, 1206 package, 0.25W, 1%.

Should R51 and R42 be removed? What is the impact if it is not removed?

Regards，

Hailiang

over 1 year ago

0 Carolus Andrews over 1 year ago

TI__Mastermind 19385 points

Hailiang,

It does not look like the schematic came through. Would it also be possible to see a layout here?

0 kai klaas69 over 1 year ago

Guru 140200 points

Hi Hailang,

to post an image use the "Insert" feature of the input box.

Kai

0 Hailiang Zhang over 1 year ago in reply to kai klaas69

TI__Expert 7075 points

Hi Kai，

Thanks for reminder. Pls see

Regards,
Hailiang

0 kai klaas69 over 1 year ago in reply to Hailiang Zhang

Guru 140200 points

Hi Hailang,

the LMBR230 is a 30V Schottky diode. R42 and R51 will burn out either when 30V is exceeded or when the input voltage goes negative. Keep in mind that negative input voltages will damage the INA226. So, removing these resistors may result in a damage of INA226 itself, if the negative going input voltages still arrive the INA226.

Kai

0 Carolus Andrews over 1 year ago in reply to kai klaas69

TI__Mastermind 19385 points

Hailang,

Kai is correct here that the Schottky's could be increasing current through the resistors under these conditions. Is it a specific condition that is burning out the resistors, or are they simply burning out under steady state conditions?

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INA226: Resistor burned