| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that a chopper type comparator having switches 14, 16 for connecting either of a first input terminal 2 and a second input terminal 4 to a capacitor 8, and a series circuit of a pMOS transistor 10 and an nMOS transistor 12 suffers a variation in a comparator threshold voltage and ends in a wrong determination of magnitude relationship when a supply voltage V<SB POS="POST">DD</SB>varies. <P>SOLUTION: A voltage of the capacitor 8 is not transmitted to a gate of the pMOS transistor 10. Instead, a source-gate voltage of the pMOS transistor 10 is kept constant to limit a source-drain current within a constant current. Even when the supply voltage V<SB POS="POST">DD</SB>varies, the comparator threshold voltage is kept constant. This can prevent a wrong determination resulting from a variation in the supply voltage V<SB POS="POST">DD</SB>. <P>COPYRIGHT: (C)2012,JPO&INPIT |
