The Monterey subsystem reference design is a high-accuracy industrial loop powered sensor transmitter that connects to any standard PT1000 resistance sensor and converts the linearized temperature to a 4-20mA current signal, which is immune to noise and remains constant over long distance. The 4-20mA current loop is widely used as an analog communication interface in industrial applications for transmitting the data from remote sensors to a programmable logic controller (PLC) in a central control center over a twisted pair cable. There are four main advantages of the current loop. First, the accuracy of the signal is not affected by the voltage drop in the loop, as long as power-supply voltage is greater than the total voltage drop across the loop. Secondly, it uses two wires for power as well as data communication over the entire loop. Thirdly, it is more immune to noise. And lastly, it is offered at a low cost and easy installation. The Monterey design is based on the complete Maxim solution which combines ultra-low power, high accuracy and high precision. It uses the following: MAX44248 low-noise, zero drift op amp; MAX11200 high-accuracy, low-power, 24-bit delta-sigma ADC; MAXQ615 low-power microcontroller; MAX5216 low-noise, high-accuracy, low-power 16-bit ADC; MAX9620 low-power op amp; MAX15007 wide input voltage low-power LDO. This loop-powered sensor transmitter is targeted for industrial sensors, industrial automation, and process control, but it can be used in any application requiring high-accuracy conversion. Simplicity, reliability, good noise immunity, long distance, and low cost make the Monterey interface well suited for industrial process control and automation of remote objects.