AN2938 Datasheet, PDF (1/39 Pages) STMicroelectronics – Power system demonstration kit based on the PM6686 dual

AN2938
Application note
Power system demonstration kit based on the PM6686 dual
step-down controller with adjustable voltages and adjustable LDO
Introduction
The PM6686 is a dual step-down controller with adjustable output voltages, adjustable LDO
and charge pump circuit for notebook power systems, and this demonstration kit represents
a typical application circuit. The demonstration kit for system supply allows the testing of all
the PM6686 functions and provides two switching sections, with 5 V (OUT1) and 3.3 V
(OUT2) outputs from 8 V to 28 V input battery voltage. The operating switching frequency of
the two sections is 400 kHz/300 kHz, respectively. Each switching section delivers more
than 8 A of output current. An internal linear regulator can provide 5 V @ 100 mA peak
current. The charge pump circuit provides an auxiliary 12 V output voltage.
Figure 1. PM6686 demonstration kit for system supply
June 2009
Doc ID 15429 Rev 1
1/39
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