I would like to design a simple board which controls a resistor as a heater. At T(1), heater (resistor) will be ON and at T(2), heater will be OFF and T(1)<T(2).I can set the R(SENSE) and hysteresis values and if i do so, I understand that my output voltage V(TEMP) is about 1V so it is not suitable to heat a 150k resistor for example.Can I increase the output voltage V(TEMP) via an op-amp and what possible errors will occur on hysteresis or on temperature sensing if I do so? Is there another way of doing this board via another product?It says LM57 uses NTC for V(TEMP) in datasheet. Does this mean I can not control the heater as temperature is inversely proportional to V(TEMP) output so that as temperature decreases, voltage on V(TEMP) is increased?Regards.
Hi Kerem,
I want to inform you that I am currently working on this, and get back to you sometimes tomorrow.
Aaron
Please refer to the LM57 datasheet pages 10, 11, and 12, which show the Vtemp value at each temperature. I hope that what you are looking for.
I don't see a problem if you use the op-amp to increase the V(temp) as long as you keep the output load regulation within the specs. Please see the LM57 datasheet on my page 6.