Hello,
I am working on a design that is supposed to work from -55°C to +70°C and its storage temperature range is -60°C to +85°C.
I am using an INA826 as a bridge amplifier and the XTR117 for a current-loop.
But the INA826 is given to work from -50°C (instead of -55°C) and the XTR117 is given to be stored at the minimum of -55°C (instead of -60°C).
Does anyone know equivalents for those components which meet temperatures requirements ?
Thank you
Hi Cyrille,
But the INA826 is given to work from -50°C (instead of -55°C)
Does anyone know equivalents for those components which meet temperatures requirements ?
Below is a list of instrumentation amplifier that may operate down to -55C. -55C is aerospace and/or military specification or grade, and the part selections are limited.
Please read the datasheet carefully. Some of the parts are specified for the low temperature range, but datasheet's performance specification is only guaranteed from -40C to 125C.
the XTR117 is given to be stored at the minimum of -55°C (instead of -60°C).
XTR117 has the similar dilemma. The absolute max. ratings are specified from -55C to 125C, but the datasheet's performance specification is only guaranteed from -40C to 125C. There are no good recommendation here. If the -55C operating temperature requirements are part of the design requirements, you may have to design the V-to-I current loop via the discrete components.
Note: -55C means that the XTR117 is able to power up and operate normally when the part is soaked at -55C for an extended period.
Alternatively, you may select XTR117 IC, and perform the additional low temperature validation tests so that the part will meet the design requirements. These are often steps taken by engineers who are unable to find guaranteed specification in design in order to meet the low temperature requirements.
If you have other questions, please let us know.
Best,
Raymond
Hi Cyrille,
it will be mandatory to perform those tests on every component batch that will be use.
From the high temperature instrumentation amplifier (IA) selection, we have the following possibilities that the operating temperature are rated at -55C, also see the pricing and availability, which the performance specification is guaranteed within the specified temperature range in the datasheet.
And for the XTR117, I already though about discrete components but my PCB is really small and I don't think I will be able to implente this function with discrete components.
The discrete V-to-I current loop transmitter may be constructed in a very small footprint.
The image below captured high temperature precision op amp options for the low temperature application.
I do not believe that we have V-to-I 4-20mA current loop transmitter IC that is guaranteed to operated down to -55C. One of the option is to construct the circuit in discrete circuit. I realized that you may not have a lot of space on a PCB, but there is a little option if the requirements are specified to implement 4-20mA current loop.
Here is an example of V-to-I current loop transmitter. The example is using OPA192, which is not rated at -55C, but I will be happy to provide you with a reference design, if you are able to provide me with the op amp, voltage reference selections, and design requirements. The entire circuit design can be simulated via Tina.
4237.Discrete 0-5V 4-20mA Transmitter 10102023.TSC
Enclosed is an application note FYI.
https://www.ti.com/lit/an/snoaa73/snoaa73.pdf
If you have other questions, please let me know.
Best,
Raymond
Hi Cyrille,
Below is a list of 4-20mA current loop application notes and video training clips. These may help you to select op amp choices.
The construction of the space grade 4-20mA current loop transmitter in the attached application note will not have small footprints in discrete form. However, we have large selection of small op amp forms, bandgap references and you should be able to minimize the footprint, if you want to build one in discrete.
Below is voltage reference selection and you should be able to find small footprint one for your application. You should look for SOT-23, low power and low temperature drift type for the application.
If you have other questions, please let us know.
Best,
Raymond
