Switched capacitor amplifier
AssigneeSeiko Instruments Inc.
InventorToshiyuki Uchida
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Abstract
Provided is a switched capacitor amplifier capable of outputting a stable output voltage. The switched capacitor amplifier is capable of operating so as to eliminate a charge/discharge time difference between an input capacitor (18) and an output capacitor (19). Accordingly, in a shift from a hold state to a sample state, for example, even if one terminal voltage (V2) of the output capacitor (19) abruptly increases to an output voltage (VOUT), another terminal voltage (Vs) of the output capacitor (19) does not increase abruptly. In other words, an input voltage to an internal amplifier (11) does not increase abruptly. Therefore, an output voltage of the internal amplifier (11) becomes stable and accordingly the output voltage (VOUT) becomes stable as well.
Claims2
A switched capacitor amplifier, comprising:
- an input capacitor;
- an input switch provided between an input terminal of the switched capacitor amplifier and the input capacitor;
- an output capacitor having a capacitance smaller than a capacitance of the input capacitor;
- an output switch provided between the output capacitor and an output terminal of the switched capacitor amplifier;
- an internal amplifier for amplifying an input voltage at a capacitance ratio between the input capacitor and the output capacitor, to output an output voltage;
- a storage capacitor for storing charges based on the output voltage;
- and
- a control circuit for controlling the input switch and the output switch so that the output switch is turned ON when a predetermined time period elapses since the input switch was turned ON during sampling.
Dependencies are inferred from the claim text.