This part is a kind of semiconductor called ISO1003-xx-x.

Function of this product has Two Wires 4-20mA Isolated Signal Transmitter.

Manufacturers : YUAN

Image and pinout :

Some of the text within the PDF file :

SHENZHEN SUNYUAN TECHNOLOGY CO., LTD. ISO- 1003 Two wires 4-20mA current loop Isolated Amplifier IC ISO series ISO1003 3000VDC Isolation 4-20mA current loop isolation interface IC DIP24 Pin package ISO 1003 choose type: ISO- 1003- Input□-Output□ Input rated voltage（or current） U1：0-75mV U2：0-100mV U3：0-5V U4: 0-10V U5: 0-2.5V A1：0-1mA A2:0~10mA Output Two wires 4-20mA Feature: 　 ·Low cost,small volume,standard DIP24 Pin package 　 ·Signal input /output 3000VDC isolation ·Current supplied by 4-20mA current loop，voltage range:12-32VDC 　 ·Low impedance signal input 　 ·0-5V input,100Ω or 250Ω or 500Ω resistance bypass series-wound circuits 　 ·provide 5V/3.5mA isolated power supply for user and 2.5V norm power supply in input pot. [ ... ]

ISO1003-xx-x PDF Datasheet Download