LM358B: Phase reversal

Michiaki Tanii

Expert 4650 points

Part Number: LM358B
Other Parts Discussed in Thread: LM358, TINA-TI

Hi team,

Our customer is considering the single-supply opamp with LM358B.

In the past, customer evaluated with LM358(non-B) and see the phase reversal and has concerned it for LM358B as well.

Could you kindly advise there are similar issues or not ?

Here is the conditions.

Vs = 14V, Vout = 0-5V.

Thank you and best regards,

Michiaki

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Michiaki,

the LM358B is no different in that respect. But phase reversal can only occur if the common mode input voltage range is violated. This is very well explained in section 9.3.3 of datasheet:

Kai

0 Bala Ravi over 5 years ago in reply to kai klaas69

TI__Expert 6625 points

Hi Michiaki,

That's right. Like Kai mentioned this can happen to any op amp when the input common-mode voltage range is violated.

Please let us know if you've any other questions or concerns.

Regards,

Bala Ravi

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

TI__Guru**** 167506 points

Hello Michiaki,

There is no issue with Vs = 14V, Vout = 0-5V. B or not B. Note: for Vout near zero, B is stronger sink drive near zero. Phase reversal happens when inputs violate the common mode range.

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

TI__Expert 4650 points

Let me double check at the single-supply operation.

Customer will use input voltage from 0V with supply voltage 14V.

It means there is no margin if input voltage was 0V.

Could you recommend LM358B with the above conditions ?

0 kai klaas69 over 5 years ago in reply to Michiaki Tanii

Guru 140200 points

Hi Michiaki,

do you have a schematic of planned circuit?

Kai

0 Bala Ravi over 5 years ago in reply to kai klaas69

TI__Expert 6625 points

Hi Michiaki,

The input common-mode voltage range for LM358B is (V-) to (V+) -1.5V. So for a supply of V+ = 14V and V- = 0V, your input common-mode range is 0V to 12.5V. As long as your input stays within this range, you will not experience phase reversal. But be careful even a small negative voltage can lead to this condition.

We can provide additional comments if you have a schematic for us to look at. We also have a TINA-TI model for this device available at: http://www.ti.com/product/LM358B/toolssoftware. I would highly recommend you to simulate your circuit and check your results.

I've built a simple circuit to show you the expected output when Vin is between 0V to 14V. LM358B.TSC

Please let us know if you've any questions.

Regards,

Bala Ravi

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LM358B: Phase reversal