OP07: OP07

Jigar Jain

Part Number: OP07
Other Parts Discussed in Thread: TIPD209, INA188, INA333, LM35

Tool/software:

Hello TI team ,

I have tried to simulate the below design. But it is not working. Could you please provide a solution to what the issue with the design or in the simulator?

Please look at it and update me ASAP.

Regards

Paresh Panchal

Regards

Jigar Jain

1 month ago

0 Raymond Zhang1 1 month ago

TI__Guru 69891 points

Hi Jigar and Paresh,

OPA07C has higher input Vcm range, and the valid input Vcm is approx. 1V range for 8Vdc single supply rail. The datasheet's Vcm range is specified for +/-15Vdc dual rails. So you are unable to use 0.5Vdc for the op amp with the 8Vdc power rail (this violates the common mode requirements in this part).

This is an old Spice model, and its behavior is a bit strange as well. I will ask our modeling engineer to take a look at the reason.

If you have other questions, please let me know.

Best,

Raymond

0 Jigar Jain 1 month ago in reply to Raymond Zhang1

Prodigy 30 points

Hello Raymond,

Thanks for your feedback. Please provide the latest model for further simulation. Let me inform you I would like to interface K- and J-type thermocouples. Before moving to PCBA, I have tried to simulate my design. But unfortunately, simulation was not working due to this, so I have tried with a simple non-inverting amplifier. But that also not simulate. I hope you will understand and give me a proper solution, including the thermocouple interface. Waiting for your further response.

Thanks

Jigar Jain

0 Raymond Zhang1 1 month ago in reply to Jigar Jain

TI__Guru 69891 points

Hi Jigar and Paresh,

Here is the simulation.

OP07D E2E 05112025.TSC

Here are some references.

https://www.ti.com/lit/an/snoa544a/snoa544a.pdf?ts=1746973868297&ref_url=https%253A%252F%252Fwww.google.com%252F

https://www.ti.com/tool/TIPD209

https://www.ti.com/video/6020534075001

https://www.ti.com/lit/an/sbaa355a/sbaa355a.pdf?ts=1746893887054

https://www.tij.co.jp/jp/lit/ug/tiduba5/tiduba5.pdf

If you have other questions, please let me know.

Best,

Raymond

0 Jigar Jain 1 month ago in reply to Raymond Zhang1

Prodigy 30 points

Hello Raymond,

Thanks for providing design and the simulation model of OP07.

Let me know if I will simulate the design with the provided OP07D; then will the design work with the OP07C?

I have referred to the TIPD209 design. Now let me know, can you provide a simulation model, and can I use 5V instead of 24V for the INA188? Also, let me know, Can i use INA333 instead of INA188 ?

Regards

Jigar Jain

0 Raymond Zhang1 1 month ago in reply to Jigar Jain

TI__Guru 69891 points

Hi Jigar,

Jigar Jain said:
Let me know if I will simulate the design with the provided OP07D; then will the design work with the OP07C?

The Spice model OP07D and OP07C are the same.

Jigar Jain said:
can you provide a simulation model, and can I use 5V instead of 24V for the INA188? Also, let me know, Can i use INA333 instead of INA188 ?

Yes, you can use INA333 to replace INA188 for the TIPD209 circuit. The differences are within the specification of the IA, but you need to calibrate the thermal couple circuit anyway.

Enclosed is the temperature related references.

Sensors and Analog Interface.ppt

Best,

Raymond

0 Jigar Jain 1 month ago in reply to Raymond Zhang1

Prodigy 30 points

Hello Raymond,

Thanks for providing information. I will be going with the below design. I would request look it the below image and provide your feedback if there are any issues.

0 Raymond Zhang1 1 month ago in reply to Jigar Jain

TI__Guru 69891 points

Hi Jigar,

Please put this together in Tina and I will show you how to simulate the circuit. Here is what you need.

Here is your INA333's operating point with input TC signal within +/-31mV range. You can download the tool from the link below.

https://www.ti.com/tool/ANALOG-ENGINEER-CALC

Best,

Raymond

0 Raymond Zhang1 1 month ago in reply to Raymond Zhang1

TI__Guru 69891 points

Hi Jigar,

Here is an example that I used low power op amp to construct the TC circuit.

INA333 TC with RTD Cold Junction Comp.TSC

The RC filter figures have not finalized, but this is the circuit, if you want to use single supply rail, e.g. 3.3Vdc.The back to back reverse diodes are optional, If you do not want to use back to back diode, I would recommend to use 1kohm RTD for cold temperature junction compensation.1kohm resistors at the INA333's input and lower the differential and common mode capacitor values. The INA333 has ESD protection internally and it should protect a typical EMI and transient events. 1kohm will be able to limit the current in a great deal.

If you have other questions, please let me know.

Best,

Raymond

0 Jigar Jain 1 month ago in reply to Raymond Zhang1

Prodigy 30 points

Hi Raymond,

Regarding cold junction compensation, we will use the external temperature sensor like LM35 or the controller's internal sensor. So, i think there's no need for me to RTD for this CJC.

0 Raymond Zhang1 1 month ago in reply to Jigar Jain

TI__Guru 69891 points

Hi Jigar,

Jigar Jain said:
Regarding cold junction compensation, we will use the external temperature sensor like LM35 or the controller's internal sensor

ok, this is up to your design option. Keep in mind, the accuracy of CJC will affect the accuracy of the temperature measurement. The temperature difference in TC is automatic compensated by CJC in the TIPD209 design. If you use other mean to sense and compensate CJC (e.g. using software code), please make sure that you know how the Seebeck effect works. The K, J or T and others TCs have different curves and linear range of each Temperature vs. Vtc (the corrected temperature differences). For wide temperature range, these curves are not linear and Temperature measurement errors can be large.

Best.

Raymond

0 Jigar Jain 1 month ago in reply to Raymond Zhang1

Prodigy 30 points

Hello Raymond,

Will manage for CJC and accuracy. Now what about the design that I have provided without CJC (RTD)? Is it OK? Please refer below design, and again, let me know if need any changes.

0 Raymond Zhang1 1 month ago in reply to Jigar Jain

TI__Guru 69891 points

Hi Jigar,

I sent you a complete simulation, see the previous attached file.

Jigar Jain said:
Now what about the design that I have provided without CJC (RTD)? Is it OK?

The circuit is missing input common mode voltage, see my simulation.

If you have other questions about the IA, I will forward you to PSC team. HVA team is no longer supporting the product line.

Best,

Raymond

0 Jigar Jain 25 days ago in reply to Raymond Zhang1

Prodigy 30 points

Yes, Please connect with HVA team for product line solution.

0 Raymond Zhang1 25 days ago in reply to Jigar Jain

TI__Guru 69891 points

Hi Jigar,

You mean that you want to have a support from the PSC team. Please provide your question, and I am forwarding the query to the team.

Best,

Raymond

Amplifiers

Amplifiers forum

OP07: OP07