22.5 mV/°C analog output — direct read for the ADC
The AD22100ARZ is an Analog Devices analog temperature sensor with a 22.5 mV/°C output scale — the voltage rises linearly with temperature, so a 0°C reading is 0 V and 100°C gives 2.25 V, fitting the input range of a typical 0–5 V ADC without external scaling.
Supply voltage and temperature grade — board-fit reality
Runs on a 4 V to 6.5 V supply, so it works off a 5 V rail with margin for noise or a 3.3 V system if a boost regulator is present — the output swing at 6.5 V supply reaches about 3.25 V at 150°C, so the ADC reference must be chosen to avoid clipping the top end. The sensor itself is rated for -50°C to 150°C ambient, but the local sensing range tops out at 85°C — above that the output still tracks temperature but the accuracy spec is not guaranteed, so for a 125°C engine-bay monitor you need the AD22100SRZ which guarantees accuracy across the full -50°C to 150°C band.
