This part is a kind of semiconductor called B59601.

Function of this product has Sensors Limit Temperature Sensors.

Manufacturers : EPCOS

Image and pinout :

Some of the text within the PDF file :

Sensors Limit Temperature Sensors, SMDs, EIA Size 0603 Applications I I I I I B59601 A 601 Dimensional drawing 0,8±0,15 0,9 max. 1,6±0,15 DC/DC converters Home appliances Dimmers Electronic ballasts Temperature management in automotive electronics Features I I I I I Thermistor chip with lead-free tinned terminations Small size Fast and reliable response Suitable for reflow soldering Suitable for automatic placement Termination TPT0698-5-E Dimensions (mm) Options I Other TNTT values on request Delivery mode I Blister tape, 180-mm reel General technical data Max. operating voltage (TA = 0 … 40 °C) Max. measuring voltage (TA – 25 K … TNTT + 15 K) Rated resistance (V PTC ≤ 2,5 V) Operating temperature range (V ≤ V meas,max) Electrical specifications a [ ... ]

B59601 PDF Datasheet Download