The present invention provides a circuit having a filter with an amplifier circuit for filtering and amplifying an input signal to generate an output signal, wherein a corner frequency of the filter is adjustable to control a settling time of the output signal.

The present invention provides a circuit having a filter with an amplifier circuit for filtering and amplifying an input signal to generate an output signal, wherein a corner frequency of the filter is adjustable to control a settling time of the output signal.

An I-V conversion module includes: a current output type sensor, a pre-integral circuit, a charge transfer auxiliary circuit, and an I-V transformation circuit including an inverting amplifier. The current output type sensor is connected to an input end of the I-V transformation circuit through the pre-integral circuit. The charge transfer auxiliary circuit connects in parallel with the inverting amplifier. When both the pre-integral circuit and the charge transfer auxiliary circuit are open circuits, the pre-integral circuit pre-integrates the induction current output by the current output type sensor to store pre-integral charges. When both pre-integral circuit and the charge transfer auxiliary circuit are closed circuits, the pre-integral charges are transferred to the I-V transformation circuit. In these embodiments, both the time for establishing the I-V conversion module and power consumption can be reduced.

The present invention provides a circuit having a filter with an amplifier circuit for filtering and amplifying an input signal to generate an output signal, wherein a corner frequency of the filter is adjustable to control a settling time of the output signal.

An I-V conversion module includes: a current output type sensor, a pre-integral circuit, a charge transfer auxiliary circuit, and an I-V transformation circuit including an inverting amplifier. The current output type sensor is connected to an input end of the I-V transformation circuit through the pre-integral circuit. The charge transfer auxiliary circuit connects in parallel with the inverting amplifier. When both the pre-integral circuit and the charge transfer auxiliary circuit are open circuits, the pre-integral circuit pre-integrates the induction current output by the current output type sensor to store pre-integral charges. When both pre-integral circuit and the charge transfer auxiliary circuit are closed circuits, the pre-integral charges are transferred to the I-V transformation circuit. In these embodiments, both the time for establishing the I-V conversion module and power consumption can be reduced.

In a sensor reader, an IC chip has a function for amplifying and outputting a sensor signal from each sensor element included in a sensor array, and includes a plurality of channel amplifiers connected each of the sensor elements. When an output switch is closed and the IC chip is in the outputting state, channel switches operate sequentially, and sensor amplification signals are output sequentially from the channel amplifiers. When the output switch is open and the IC chip is in the non-outputting state, a bias current of an operational amplifier of the channel amplifier is decreased, the IC chip is set to a low power consumption state, and gain of the operational amplifier is decreased.

In a sensor reader, an IC chip has a function for amplifying and outputting a sensor signal from each sensor element included in a sensor array, and includes a plurality of channel amplifiers connected each of the sensor elements. When an output switch is closed and the IC chip is in the outputting state, channel switches operate sequentially, and sensor amplification signals are output sequentially from the channel amplifiers. When the output switch is open and the IC chip is in the non-outputting state, a bias current of an operational amplifier of the channel amplifier is decreased, the IC chip is set to a low power consumption state, and gain of the operational amplifier is decreased.