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发表于 2011-2-5 02:57:40
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you can make this fairly easy or fairly difficult.
on the easy side:
1) you can use a digital pot controlled by a mcu which also adc's the output voltage and displays it on a lcd - all fairly easy to do.
this has the advantage of being the closest to the analog solution.
2) if you allow higher ripple, you can use a mcu to adc's the output voltage. when the output voltage is below a threshold, the mcu turns on the simpleswitcher (many of them have an ON/OFF pin, or a PWM pin); and when the output voltage is above a threshold, the mcu turns off the switcher too.
this is the simpleset and most efficient solution, but with the highest ripple.
3) if you have a mcu with a DAC, you can then have the mcu driving the switcher's feedback pin directly. the coding for this approach is the most difficult of the three. |
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