Abstract: A single stage switched capacitor programmable gain amplifier uses programmable capacitor values to adjust gain factors. The operation of the amplifier is described by a transfer function having two gain factors: (C1/C2) and (C2/C3). The gain factor of C1/C2 applies during the holding phase and the gain factor of C2/C3 applies during the sampling phase. The transfer function is equal to the product of the two gain factors: (C1/C2)×(C2/C3) such that the transfer function is equal to (C1/C3). The intermediate element C2 can be adjusted to maximize bandwidth because C2 is independent of the total transfer gain. Accordingly, the intermediate element C2 is substantially fixed from the holding phase to the following sampling phase such that the bandwidth of the programmable gain amplifier is maximized in the two phases.

Abstract: A digital-to-analog converter (DAC) comprises a current DAC, first and second resistance circuits, and an operational transconductance amplifier (OTA). The first resistance circuit is coupled between a first node and an output of the OTA. The second resistance circuit is coupled between the first node and a power supply node. The current DAC is arranged to provide an analog current to a first node in response to a digital input signal. The OTA has a first input that receives a stable DC reference voltage signal, and a second input that is coupled to the first node. A charge pump provides the local supply voltage of the OTA to improve the system dynamic range. The output voltage corresponds to the sum of the voltages across the first and second resistance circuits. An increase in the current produced by the current DAC causes a decrease in the output voltage.

Abstract: The present invention is directed towards a single stage switched capacitor programmable gain amplifier. The operation of the amplifier is described by a transfer function having two gain factors: (C1/C2) and (C2/C3). The transfer function is equal to the product of the two gain factors: (C1/C2)×(C2/C3) such that the transfer function is equal to (C1/C3). The combination of the two different gain factors provides a wider range and finer step programmability of the amplifier. The amplifier does not have an idle phase, which reduces power dissipation. Additionally, the amplifier requires less switching which results in reducing the thermal noise and the switching noise produced by the amplifier.