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Design a wide-voltage-band buck regulator

1/27/2012 09:09 PM EST
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PowerCycle
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re: Design a wide-voltage-band buck regulator
PowerCycle   2/3/2012 9:44:35 PM
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The op-amps drive high-impedance inputs and can have 10 uA quiescent current and the zener diode references have low bias current (they also source low current to the op-amps). For a buck regulator with a Vfeedback input of 100K ohms (which the last op-amp stage drives), the op-amps and zeners+bias could be under 100 uA at 3V max (assuming Vref = 1.25 V). If the inductor and FET see much more current than this (say in the high mA), the added ineffciency of the additional components is very small compared to the power of the overall system. These days most bucks are at 90% efficiency or better and so a few extra percent is all that may be realized, but even 1% improvement is worth a lot if the system is high power (like a cell phone).

alager12345
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re: Design a wide-voltage-band buck regulator
alager12345   2/3/2012 4:39:50 PM
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For all the extra components, what is the expected efficiency gain? Also don't forget to account for the power consumption of the additional op-amps and 3 voltage references.

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