| 摘要 |
A combined programmable gain and integrating amplifier comprises an operational amplifier having an inverting input terminal coupled to a reference voltage. A plurality of capacitors are selectively connectable in parallel between the inverting input terminal and the amplifier output terminal. At least one terminal of each capacitor is connected to the inverting input terminal. A plurality of controllable switches are connected in series circuit between a corresponding one of the capacitors and the amplifier output terminal for coupling the capacitors in circuit between the inverting input terminal and the output terminal. In a first operational state, each of the switches connects the capacitors between the input and output terminals. In a second operational state, the switches connect selected ones of the capacitors the reference voltage. Another controllable switch is connected in circuit between the inverting input terminal and the output terminal for selectively short-circuiting the capacitors in order to reset the amplifier integration function.
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