Development of a QAC with dual sensitivities using a bipolar full-custom IC technology

A charge-to-amplitude converter (QAC) has been developed using the technology of a bipolar full-custom integrated circuit (IC). The newly developed QAC has two channels with different sensitivities: a high-sensitivity QAC channel and a wide dynamic range QAC channel. The sensitivities of both QAC channels are different by a factor of four. The input current signal is converted into a voltage amplitude within the gate signal width. The output voltages of the QAC are directly proportional to the input current signal. The QAC employs a current splitter at the input stage to meet a requirement for a wide dynamic-range conversion scheme. Both QAC channels with different sensitivities have achieved a non-linearity of 0.1% (10-bit-equivalent). The equivalent dynamic range can be realized to be 13 bits.