The ISL21400 features a precision voltage reference combined with a temperature sensor whose output voltage varies linearly with temperature. The precision 1.20V reference has a very low temperature coefficient (tempco), and its output voltage is scaled by an internal DAC (VREF) to produce a temperature stable output voltage that is programmable from 0V to 1.20V. The output voltage from the temperature sensor (VTS) is summed with VREF to produce a temperature dependent output voltage. The slope of the VTS portion of the output voltage can be programmed to be positive or negative in the range -2.1mV/°C to +2.1mV/°C. A programmable gain amplifier (PGA) sums the VTS and the VREF voltages and provides gains of 1x, 2x, and 4x to scale the output up to 4.8V and the slope to ±8.4mV/°C. The VREF and VTS terms are programmable with 8 bits of resolution via an I2C bus and the values are stored in non-volatile registers. The PGA gain is also set via the I2C bus and the value is stored in a non-volatile register. Non-volatile memory storage assures the programmed settings are retained on power-down, eliminating the need for software initialization at device power-up.