Looking for temperature control chip for heaters

Hi Gianluca,

Thanks for your question. Let me begin my answer by making some general statements about TI's IC temperature sensors.

1. An IC temperature sensor measures it's internal temperature. If the IC dissipates power, it will have a local temperature rise. This temperature rise would then appear as a temperature error. For this reason, you won't find an IC temperature sensor with significant output current drive. You won't be able to drive a heater directly.
2. There aren't many IC temperature sensors that operate on 12V. You can see all 6 that we offer here: https://www.ti.com/sensors/temperature-sensors/products.html#p0max=12;30 TMP51x are the only devices on this list with an I2C interface. It has a specialized purpose in power monitoring, which may not be appropriate for your application. 
3. Here is a list of digital temperature sensors that support 5V operation. https://www.ti.com/sensors/temperature-sensors/products.html#p0max=5;30&o7=Digital%20temperature%20sensors Most of these devices are I2C. Most of these devices have an ALERT or thermal limit feature which can be programmed to toggle an output when a temperature limit is exceeded. This temperature limit feature will generally have a preset or configurable hysteresis. This feature could enable a FET/power-stage that powers your heater as a crude thermal control. We have many customers building systems like this.
4. You won't find an IC temperature sensor that provides linear control output. You could potentially use a temperature sensor with analog output in a circuit which provides linear heater control. Such an analog temperature sensor would not have a digital interface at all. See TMP20, LMT84, etc. There are products (see AMC6821) which provide a PWM output intended for a fan. It's probably not feasible to invert the operation of the AMC6821 to drive a heater, but I haven't tried to verify this.

Please let me know if you have any follow-up questions.

thanks,

ren