Linear regulators form a core part of most printed circuit boards’ voltage regulation. The TL1963 is a great part that is an excellent addition to any library.
The Good
The TL1963 comes in a SOT-223 package. It is smaller than a DPAK, but offers more heat dissipation than a SOT-23 package. I like to keep all components in a design cooler than 50 degrees C, and if you’re dissipating less than 250mW in this package, it usually will stay cool with about 0.5 inches sq of copper. Additionally, this linear regulator is good to a maximum input voltage of 20V, allowing inputs from a broad variety of rails. Also, the output is stable with ceramic caps (more about this later).
The Bad
This is not the cheapest regulator. Pricing at Digi-key is about $3 for 1, $1.50 for 1k pricing.
Design Notes
Many cheaper linear regulators need output capacitance with some series resistance (tantalums usually) in order to not go into oscillations. This one doesn’t require any, and is stable with ceramic (near 0 ohms) output capacitors.
In order to get good output regulation (seen in the datasheet as PSRR), you can’t count on the lowest dropout voltage. Having at least 1.1V dropout voltage for this part will give you significant output regulation. I just had a design where I had 400mV low-frequency noise from a switching regulator, and a linear cleaned it up to 10mV with a dropout voltage of 2.5V.
If you have a significant dropout voltage (input minus output), you may want to put a series resistor inline with the input to the regulator. Having a 1 ohm 2512 resistor will give you a lot of design flexibility if your regulator starts getting too hot. You can sub it out with a larger resistor (if your output load is somewhat regular and not pulsed). This will allow you to drop some of the heat in the resistor.