a single - trim cmos bandgap reference with a < formula formulatype = " inline " > < tex notation = " tex " > $ 3 \ sigma $ < / tex > < / formula > inaccuracy of < formula formulatype = " inline " > < tex notation = " tex " > $ \ pm $ < / tex > < / formula > 0 . 15 % from < formula formulatype = " inline " > < tex notation = " tex " > $ { - } $ < / tex > < / formula > 40 < formula fo .
A low voltage low 1/f noise CMOS bandgap reference