INA139NA/3K

INA139NA/3K is a Texas Instruments INA139 high-side current-shunt monitor — 2.7 to 40 V common-mode input range, transconductance output of 1000 µA/V, in SOT-23-5, tape-and-reel packing of 3000 (/3K), -40 to +125 °C. High-side sensing with a current output is the selection point: the shunt sits in the supply line so ground stays clean, and the gain is set by a single external load resistor — 10 kΩ gives a voltage gain of 10 — with no matched resistor network to buy or drift. Selection advice: the output is a current, not a voltage — you must provide the load resistor, and the datasheet recommends buffering it before driving an ADC. For common-mode voltages above 40 V use the INA169 (60 V) instead; the two share the SOT-23-5 footprint but are different parts. The 60 µA quiescent current keeps always-on current monitoring cheap in power terms. The /3K suffix is the 3000-piece reel; /250 is the 250-piece reel for prototypes. Evidence: TI INA139 datasheet (SBOS181) and package addendum confirm 2.7-40 V, 1000 µA/V, SOT-23-5 and 3000-reel packing. Match the full INA139NA/3K code.