@Scott-Sumner LD1117A manufactured (most probably) by UTC www.unisonic.com.tw SOT-223 The full SMD marking of a device (on a Breadboard Dock what I've seen): LD1117AG 33AQTJTE where LD1117AG : A 1A output current, G Green 33A : 3.3V output voltage, A pin code 1 GND, 2 Vout, 3 Vin Absolute Maximum DC Input Voltage 18V - recommended max. 15V Vout 3.234...3.366 @ Vin 4.75...10V, Iout 0...1000 mA Dropout Voltage max. 1.30V @ Iout 1A Built-in current limit and over temperature protection - of course. Attention! I did not measure these data. The voltage rating of the SMD capacitor at Vin pin (on the Breadboard Dock) can be less than 18V . It's an analog regulator without heatsink - so you should watch also its thermal data / power dissipation if you increase the input voltage.