OPA596: amplify with single end out put and differential out put

Corry Weng

Intellectual 1980 points

Part Number: OPA596
Other Parts Discussed in Thread: OPA392

Tool/software:

Hi team,

Sorry that I am not sure how to filter out the correct product meeting the needs below on the website

Could you please help suggest a suitable solution meeting below requirement?

one amplifier which single powered, 3.3~5V.

1, for single end output, 1~3 times gain.

2, differential output, 3~5 times gain.

Also, how to convert signal from 1/2 VCC~VCC to 0~VCC

Thanks

Corry

3 months ago

0 Raymond Zhang1 3 months ago

TI__Guru 53971 points

Hi Corry,

OPA596 is HV op amp up to 85V. Your application seems to meet low voltage application requirements and so 5V op amp should work well.

What type of load is the application driving? What is max. output current? what is operating frequency?

Corry Weng said:
Also, how to convert signal from 1/2 VCC~VCC to 0~VCC

This is level shifting issue in op amp. Please specify what you are trying to do, and I can put a circuit together.

Best,

Raymond

0 Corry Weng 2 months ago in reply to Raymond Zhang1

TI__Intellectual 1980 points

Hi Raymond,

The application is connecting HALL IC or TMR sensor.

For HALL IC, output current max 5mA.

TMR, output maximum voltage +/- 1560mV, power consumption 0.3mW.

Frequency : 10K~100KHz

For HALL IC, normal output is 1/2 VCC, depends on what polar magnet close it.

The output will be 1/2 VCC to 0V or 1/2 VCC to VCC.

Both conditions, I want to get shift circuit transfer output voltage from 0V to VCC.

Due to voltage span enlarge then ADC much easier to know distance change between magnet and HALL IC.

Thanks

Corry

0 Raymond Zhang1 2 months ago in reply to Corry Weng

TI__Guru 53971 points

Hi Corry,

I assumed that you are looking for op amp level shift circuit. Enclosed is two references.

https://www.ti.com/lit/an/sbaa374/sbaa374.pdf?ts=1720020901447&ref_url=https%253A%252F%252Fwww.google.com%252F

https://www.ti.com/lit/ab/sboa038a/sboa038a.pdf?ts=1720020795328&ref_url=https%253A%252F%252Fwww.google.com%252F

Enclosed is two more simulation. I used OPA392 as an example, which is 5V precision op amp.

OPA392 level shift 07032024.TSC

There are many ways to perform the op amp level shift circuit. For TMR sensor application, the input front stage may be INA, difference amplifier or even even non-inverting op amp configuration (like buffer). You may perform level shift in all these circuits. You may even use summing amplifiers (inverting or noninverting config) to perform the level shift.

If the output has to down to 0Vdc, it may require small Vee supply, such as LM7705 (-0.233V) otherwise, it may not swing all the way to GND, depending the type of op amp that is selected.

Let us know if you have additional questions.

Best,

Raymond

0 Corry Weng 2 months ago in reply to Raymond Zhang1

TI__Intellectual 1980 points

HI Raymond,

If it is possible change simulation 2 VCC to 5V or 3.3V.

From circuit showing, it seems applied 15V.

Thanks

Corry

0 Raymond Zhang1 2 months ago in reply to Corry Weng

TI__Guru 53971 points

Hi Corry,

Here it is. Please be specific. In the application note, there are many level shift circuit. If you refer to the following, then this is the modification.

OPA392 level shift 3p3V 07042024.TSC

Best,

Raymond

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OPA596: amplify with single end out put and differential out put