Data Sheet

A-Star 32U4 Mini SV, bottom view with

dimensions.

4.4. A-Star 32U4 Mini SV regulator

The A-Star 32U4 Mini SV can be powered from a 5 V to 36 V

external source. The input voltage is regulated to 5 V by a 500 mA

ISL85415 switching step-down (buck) converter from Intersil. (We

also make a standalone regulator [http://www.pololu.com/product/2843]

based on this integrated circuit.)

As shown in the left graph below, the SV’s switching regulator has

an efficiency – defined as (Power out)/(Power in) – of 80% to 95%

for most combinations of input voltage and load.

The A-Star’s components, including the microcontroller and LEDs, draw 30 mA to 40 mA in typical applications.

The rest of the regulator’s achievable output current, which depends on input voltage as well as ambient conditions,

can be used to power other devices. The right graph above shows output currents at which the voltage regulator’s

over-temperature protection typically kicks in after a few seconds. These currents represent the limit of the regulator’s

capability and cannot be sustained for long periods; a good estimate for the maximum continuous regulator output

current is 60% to 70% of the values shown in the graph or 500 mA, whichever is lower (the regulator is not rated for

operation above 500 mA).

4.5. A-Star 32U4 Mini schematic and dimensions

Schematic diagram

The schematic diagram for the A-Star 32U4 Minis is available as a PDF: A-Star 32U4 Mini schematic diagram

[http://www.pololu.com/file/download/a-star-32u4-mini-schematic.pdf?file_id=0J780] (451k pdf).

4. A-Star 32U4 Mini Page 16 of 47