Our customer uses this part from TI : LM26CIM5-HHD . This has a trip point of 0 degrees. However , our customer wants a part with a fixed trip point at 7 degC switch-on? I think that should be p/n LM26CIM5-HSD – but TI do not produce such a device.
Could you have a 7 degree temp switch ?
Regarding factory set trip point sensor we have the family ADT650x, but the closest to 7C will be 5C (as they go in 10C increments). See the table below.
Also, ADT6401/ADT6501 have the same trip points available, in addition of a hysteresis, although this is pin selectable, and would be set according to the voltage level connected on three of its pins :
However, we have TMP01, which is resistor programmable. This one has an output pin, that provides a voltage proportional to absolute temperature (5mV/K) in addition to an over temperature output and an under temperature out pin, whose limit are determined by external resistors.
So, if let's say we select zero hysteresis and 7C, the resistor needed on R1 would be 157k. I don't know if that would be an option for you, but playing around with resistor and hysteresis values you could set the temperature limits according to their needs.http://www.analog.com/static/imported-files/data_sheets/TMP01.pdf