LMV358-N-Q1: LMV358Q1MAXNOPB

Mohana Krishnan M

Part Number: LMV358-N-Q1
Other Parts Discussed in Thread: LMV358, LMV358-N, TL972-Q1, RC4580-Q1, TL3472-Q1, TL3472, TLV272-Q1, TLV2172-Q1

Dear Team,

We are looking into the below part - LMV358Q1MAXNOPB

Can this part handle +/-5V dual power supply?

Is LMV358Q1 and LMV358NQ1 same? unable to identify datasheet of LMV358Q1

Kindly support.

Regards,

Mohana Krishnan M

over 5 years ago

0 Ron Michallick over 5 years ago

TI__Guru*** 147906 points

Hello Mohana,

Welcome to the e2e forums. I hope you will find the forums helpful. The LMV358 will not survive a 10V supply or +/-5V which are effectively the same. The LMV358 and LMV358-N have similar but different designs. What was the full part number for the LMV358Q1?

This link should list all automotive rated dual op amps that have 10V or greater maximum supply voltage

http://www.ti.com/amplifier-circuit/op-amps/products.html#p480=2;2&p1261max=10;180&p1498=Automotive&sort=p1130;asc

What are the key op amp parameters needed for this application?

0 Mohana Krishnan M over 5 years ago in reply to Ron Michallick

Prodigy 215 points

Full Part number - LMV358Q1MAXNOPB

It should be dual channel.

Application is for measuring Phase voltage in VFD. So, it must be capable of handling the switching frequency (10kHz), so that the waveform does not get distorted at output.

0 Ron Michallick over 5 years ago in reply to Mohana Krishnan M

TI__Guru*** 147906 points

Mohana,

LMV358Q1MAXNOPB is a LMV358-N device, there is no public LMV358QDRG4Q1 device that is based on LMV358(no N)

I suggest looking at TL3472-Q1, TL972-Q1, or RC4580-Q1

0 Ron Michallick over 5 years ago in reply to Ron Michallick

TI__Guru*** 147906 points

Mohana,

If you need more help just post a new reply and I'll support you further.

0 Mohana Krishnan M over 5 years ago in reply to Ron Michallick

Prodigy 215 points

Dear Ron,

Yes we would need your support.

I have simulated our requirement using TINA TI.

Worst case frequency = 20kHz.

Considered duty ratio = 50% (Worst case can go upto 1%)

The output waveform is getting distorted.

We would like to get clarified on the below points,

Would the front and back end Opamp support for this frequency? Kindly suggest one suitable device for the same.
Would the isolation amplifier (AMC1311BDWVQ1) support for this frequency. Because i could see that rise time is mentioned to be 1us.OPVSENSE_COMPLETE.TSC

0 Ron Michallick over 4 years ago in reply to Mohana Krishnan M

TI__Guru*** 147906 points

Mohana,

The biggest issue was that op amp U2 had the power supply connected backwards. It took me over 10 minutes find that one.

The second issue is that the input common mode rejection is poor because the input difference amplifier wasn't balanced. I changed R2 from 100k to 76k to fix that. The Vbias voltage has a 24k ohms impedance.

OPVSENSE_COMPLETE(2).TSC

The TL3472-Q1, TL972-Q1, and RC4580-Q1 are not rail to rail output so 0V to 5V output won't be possible. The TL3472 model limits output from +1V to 4V

The actual TL3472 output low voltage is more complex than that simple assumption.

To get a rail to rail output, there is slower TLV272-Q1 and faster TLV2172-Q1

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LMV358-N-Q1: LMV358Q1MAXNOPB