LDO ouptut voltage followed by VDD

frank822

如果VDD 3.3V, bandgap電壓1.5V, 得Vout 3V.
4 _0 |5 |& U: d0 \  f' o) U4 z$ h/ L當VDD 變3V, bandgap電壓1.5V,如何讓Vout變2.7V.
4 r5 r# m# D2 H1 G8 J8 }: f要確保power mos saturation, 電流流過 1A.

! g  A1 F" b, y1 E1 s方法一: detect VDD voltage, then? ....control feedback resistor?
& F( L9 ?* [+ m方法二: detect power mosfet saturation? how to detect?
! v0 G% o# [) y! m( \% |其他方法?
! B% \( y, X. i5 Z( h. Z5 I各位先進 請指導依下 謝謝

c3a1t039

你有想過在bandgap後面加上LDO去做調節??