The Texas Instruments TPS26613DDFR is a low-side current regulator in a TSOT-23-8 package. It delivers a fixed 20 mA output across a bipolar input range of -50V to 50V, making it suitable for applications where the load return must be referenced to a negative rail or where the supply can swing both polarities. The low-side sensing method places the sense element between the load and ground, which simplifies the control loop but means the regulator cannot detect a load-side short to ground.
Input range and output current — the two numbers that define the fit
The -50V to 50V input range is the headline spec: it allows this part to sit in a circuit where the supply is not ground-referenced, such as a bipolar current loop or a floating sensor interface. Most fixed regulators clip at a single-polarity maximum; the TPS26613DDFR handles both. The 20 mA output is fixed — there is no programming pin or resistor-set option. If your load needs a different regulated current, this is not the part; look at the TPS26610DDFR, which also regulates current but with a different output characteristic in the same SOT-23-8 footprint.