TLV2372-Q1: TLV2372 Multivibrator abnormal operation

Mike Jung

Part Number: TLV2372-Q1

Dear TI community.

I have questions about multibrator behavior.

Multibrator was used for EV battery voltage measurements.
The attached file is a circuit diagram and a measurement waveform.

If only 12V low voltage is connected, it is normal to operate, but if HV (360V) battery is also connected, the waveform will change.

Please let me know if there are any considerations for the circuit or layout, or if there are any other solutions.Voltage sensing.pdf

over 5 years ago

0 Ron Michallick over 5 years ago

TI__Guru*** 147906 points

Mike R63 is too high in resistance. The lower threshold on non inverting input is too close to ground. Right now it should be about 20mV which will cover the 6 mV input offset of the op amp. With ground shift and noise, that 20mV isn't enough.

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Mike,

what is the HV+ voltage range you want to convert?

Have you thought about using two overlapping ranges, one for lower voltages and the other for higher voltages?

Kai

0 Mike Jung over 5 years ago in reply to kai klaas69

Intellectual 700 points

Dear Kai

Sorry for the late reply.
The HV range is 340 to 380V with 360V being typ.

0 kai klaas69 over 5 years ago in reply to Mike Jung

Guru 140200 points

Hi Mike,

so, you only want to convert voltages between 340V and 380V? I ask, because you said that you have connected 12 low voltage to the HV+ pin. So, you don't want to convert 12V at the HV+ pin?

Kai

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TLV2372-Q1: TLV2372 Multivibrator abnormal operation