| 摘要 |
PROBLEM TO BE SOLVED: To provide a passive amplification circuit that, in amplifying differential signals, amplifies only the differential signals without requiring any reference of common mode voltage, and provide a successive approximation analog-digital converter that has effective resolution improved by one bit.SOLUTION: Differential signals are amplified by the passive amplification circuit dispensing with a reference of common mode voltage, and voltages of input signals are passively amplified twofold before a successive approximation analog-digital conversion operation is performed. The passive amplification is implemented by a plurality of capacitive elements for sampling whose connection relationships are changed with switches. This can halve an effect of comparator noise without adding to power consumption and chip size, to whereby increase effective resolution by one bit. |
