Abstract: Precise CMOS bandgap voltage and current references which uses the difference of MOS source-gate voltages to perform efficient curvature compensation are proposed and analyzed. Applying the developed design strategies, bandgap voltage references (BVR) with a temperature drift below 10 ppm/.degree.C. and a power supply drift below 10 ppm/V can be realized. For bandgap current references, both drifts can be under 15 ppm. An experimental BVR chip shows an average drift of 5.5 ppm/.degree.C. from -60.degree. C. to 150.degree. C. and 25 .mu.V/V for supply voltages between 5 V and 15 V at 25.degree. C. Due to novel curvature compensation, the circuit structure of the proposed references is simple and both chip area and power consumption are small.

Abstract: A circuit for protecting a CMOS chip against damage from electrostatic discharges (ESD) has four SCRs connected between the line to be protected and the two power supply terminals, V.sub.DD and V.sub.SS. The SCRs are poled to conduct ESD current of either polarity to each power supply terminal. The bipolar transistors for the SCRs and the associated components are arranged in the chip in an advantageous way that reduces the input/output parasitic capacitance and improves the protection capability of this proposed circuit with a low ESD trigger-on voltage.

Abstract: A circuit for protecting a CMOS chip against damage from electrostatic discharges (ESD) has four SCRs connected between the line to be protected and the two power supply termiamls, V.sub.DD and V.sub.SS. The SCRs are poled to conduct ESD current of either polarity to each power supply terminal. The bipolar transistors for the SCRs and the associated component are arranged in the chip in an advantageous way that reduces the input/output parasitic capacitance and improves the protection capability of this proposed circuit with a low ESD trigger-on voltage.

Abstract: Backward-mapping switched capacitor (SC) differentiators for MOS technology integrated circuit implementation, as well as forward mapping (FM) and bilinear-mapping (BIM) SC differentiators, are disclosed. The SC differentiator is employed in filters either alone or in combination with SC integrators. The filters include biquads, ladder filters, FIR filters, IIR filters and N-path filters.A fully differential operational amplifier with high and symmetrical driving capability is also described.

Abstract: Sigma-delta analog to digital converters based upon switched capacitor delay and switched capacitor differentiator circuits are described. These switched capacitor circuits have the advantages that they are less sensitive to clock feed-through noise, dc offset voltage and power supply voltage, etc. Design examples of one-bit second-order sigma-delta analog digital converter are given to substantiate both design methodology, circuit features and the utility of these new circuit structures.