I've wired up the Basic Circuit Connection in Figure 1 (page 6) of the XTR110 data sheet.
Supply voltage is +24 volts (between pins 16 and 2). Also ran the circuit with 12v, as 24v pumps too much wattage through my load resistor (1K at this time).
Input voltage is created using a pot across Vcc/Gnd (and I'm careful not to exceed 10v to the input).
Output goes to the gate of an FQ27P06 (enhancement mode) MOSFET; I've also used an IRF9560 here. Source is connected to Vcc (24v or 12v). Drain is connected through a 1K resistor to ground.
Applying power, I get the full 24v/12v dropped across the 1K resistor. Pot position (voltage input to XTR110 can range from 0-10v, nothing changes. Measuring the output on pin 14 I always see 1.35v (regardless of supply voltage).
Pins 1 and 13 are at Vcc (or a tiny bit below).
Zero adjust, span adjust, and 4mA span are floating, 16mA span is tied to ground. Vref adj is floating.
Changing the pot value does not affect the voltage drop across the load resistor.
Any idea what I'm doing wrong? (BTW, I've tried two separate ICs, both produce the same result).