Abstract: A circuit includes a programmable gain amplifier (PGA) having a PGA output. The circuit further includes a delta-sigma modulator having an input coupled to the PGA output. The circuit also includes a digital filter and a dynamic range enhancer (DRE) circuit. The digital filter is coupled to the delta-sigma modulator output. The DRE circuit is coupled to the delta-sigma modulator output and to the PGA. The DRE circuit is configured to monitor a signal level of the delta-sigma modulator output. Responsive to the signal level being less than a DRE threshold, the DRE circuit is configured to program the PGA for a gain level greater than unity gain and to cause the digital filter to implement an attenuation of a same magnitude as the gain level to be programmed into the PGA.

Abstract: A system includes: a reference buffer coupled to an input supply voltage; an analog-to-digital converter (ADC) coupled to an output of the reference buffer; and an output capacitor coupled between the output of the reference buffer and a ground node. The reference buffer includes: an integrator; an internal capacitor coupled between an output of the integrator and the ground node; a first gain stage with an input coupled to the output of the reference buffer; and a second gain stage with an input coupled to the output of the integrator. The output of the first gain stage is combined with the output of the integrator using a combine circuit.

Abstract: A multiplexer comprises: a first switch; a second switch; a dummy component coupled to the first switch and the second switch and configured to: reduce a first charge injection of the first switch, and reduce a second charge injection of the second switch; and an output coupled to the first switch, the second switch, and the dummy component. A method comprises: providing an output from either a first switch or a second switch; coupling, by a dummy component, to the first switch and the second switch; using a BBM action; and reducing, by the dummy component, a first charge injection of the first switch or a second charge injection of the second switch.

Abstract: A method of authorizing a transaction involves a computer server authenticating a payment cardholder from a cardholder credential, and receiving a request from a communications terminal to initiate an online transaction with the server. The server communicates with a database of clusters, each uniquely associated with a respective cardholder and identifying an authentication card and a partial payment card number. The server requests an authentication credential from the terminal in response to determining that the requested transaction possesses a high risk of fraud. The server receives the requested authentication credential, and uses the cardholder and authentication credentials to locate the authentication card uniquely associated with the cardholder and the authentication credential in the database. The authentication credential has fewer digits than the account number of the located authentication card.

Abstract: A multiplexer comprises: a first switch; a second switch; a dummy component coupled to the first switch and the second switch and configured to: reduce a first charge injection of the first switch, and reduce a second charge injection of the second switch; and an output coupled to the first switch, the second switch, and the dummy component. A method comprises: providing an output from either a first switch or a second switch; coupling, by a dummy component, to the first switch and the second switch; using a BBM action; and reducing, by the dummy component, a first charge injection of the first switch or a second charge injection of the second switch.

Abstract: An electrical device includes an integrated circuit having device circuitry and a boost converter coupled to the device circuitry. The boost converter includes a digital integrator circuit having: a first comparator; a second comparator; a counter configured to count up, count down, and pause based on a first output signal provided by the first comparator and based on a second output signal provided by the second comparator; and a digital-to-analog converter (DAC) configured to provide a feedback adjustment signal for the boost converter based on a count value provided by the counter.

Abstract: Systems and methods are disclosed for a signal convertor comprising a resistor or current source coupled to a positive virtual ground node and a negative virtual ground node, wherein the resistor or current source is configured to switch from the positive virtual ground node (VGP) to the negative virtual ground node (VGN), wherein the switching of the resistor or current source results in a shaping of the low frequency noise from the resistor.

Abstract: A chopper-stabilized amplifier includes a first transconductance amplifier and a first chopper circuit coupled to an input of the first transconductance amplifier. A second chopper circuit is coupled to an output of the first transconductance amplifier. The chopper-stabilized amplifier also includes second and third transconductance amplifiers having inputs coupled to the output of the first transconductance amplifier. The second transconductance amplifier produces an output responsive to a first notch clock signal having a first phase relative to the chopping of the second chopper circuit. The third transconductance amplifier produces an output responsive to a second notch clock signal having a second phase relative to the first phase. The output signals produced by the second and third transconductance amplifiers are added to filter ripple noise at the outputs of the second and third transconductance amplifiers.

Abstract: A temperature dependent correction circuit includes a first supply source, a second supply source, a rectifying circuit, and a reference. The first supply source is configured to supply a first signal that varies with temperature along a first constant or continuously variable slope. The second supply source is configured to supply a second signal that varies with temperature along a second constant or continuously variable slope. The rectifying circuit is configured to receive the first and second signal, rectify the first signal to produce a first rectified signal, and add the first rectified signal to the second signal to produce a correction signal. The reference is configured to receive the correction signal.

Abstract: A reference circuit may include a bandgap reference stage, a filter stage, and a buffer stage. The reference stage may be configured to generate a reference voltage or current. The filter stage may be coupled to the reference stage and may be configured to receive the reference voltage or current, filter noise from the reference voltage or current, receive a buffer output voltage or current, and filter noise from the buffer output voltage or current. The buffer stage may be coupled to the filter stage and may be configured to isolate the reference stage and the filter stage from a loading effect of a load circuit and generate a reference signal based on the reference voltage or current to drive the load circuit.

Abstract: An improved method is provided for determining whether a sample point is within a defined geographic area. Indexes for the geographic area of interest are generated in advance. Such indexes complement the traditional spatial indexing techniques such as quad tree and r-tree. The geographic area, as defined by an outer boundary, is subdivided into some regular geometric shape, preferably a rectangle, encoded into a suitable form, and indexed. Then, a simplified comparison of the sample point to the indexed regular shapes is made.

Abstract: A temperature dependent correction circuit includes a first supply source, a second supply source, a rectifying circuit, and a reference. The first supply source is configured to supply a first signal that varies with temperature along a first constant or continuously variable slope. The second supply source is configured to supply a second signal that varies with temperature along a second constant or continuously variable slope. The rectifying circuit is configured to receive the first and second signal, rectify the first signal to produce a first rectified signal, and add the first rectified signal to the second signal to produce a correction signal. The reference is configured to receive the correction signal.

Abstract: An improved method is provided for determining whether a sample point is within a defined geographic area. Indexes for the geographic area of interest are generated in advance. Such indexes complement the traditional spatial indexing techniques such as quad tree and r-tree. The geographic area, as defined by an outer boundary, is subdivided into some regular geometric shape, preferably a rectangle, encoded into a suitable form, and indexed. Then, a simplified comparison of the sample point to the indexed regular shapes is made.

Abstract: A temperature dependent correction circuit includes a first supply source, a second supply source, a rectifying circuit, and a reference. The first supply source is configured to supply a first signal that varies with temperature along a first constant or continuously variable slope. The second supply source is configured to supply a second signal that varies with temperature along a second constant or continuously variable slope. The rectifying circuit is configured to receive the first and second signal, rectify the first signal to produce a first rectified signal, and add the first rectified signal to the second signal to produce a correction signal. The reference is configured to receive the correction signal.

Abstract: A reference circuit may include a bandgap reference stage, a filter stage, and a buffer stage. The reference stage may be configured to generate a reference voltage or current. The filter stage may be coupled to the reference stage and may be configured to receive the reference voltage or current, filter noise from the reference voltage or current, receive a buffer output voltage or current, and filter noise from the buffer output voltage or current. The buffer stage may be coupled to the filter stage and may be configured to isolate the reference stage and the filter stage from a loading effect of a load circuit and generate a reference signal based on the reference voltage or current to drive the load circuit.

Abstract: A multiplexer comprises: a first switch; a second switch; a dummy component coupled to the first switch and the second switch and configured to: reduce a first charge injection of the first switch, and reduce a second charge injection of the second switch; and an output coupled to the first switch, the second switch, and the dummy component. A method comprises: providing an output from either a first switch or a second switch; coupling, by a dummy component, to the first switch and the second switch; using a BBM action; and reducing, by the dummy component, a first charge injection of the first switch or a second charge injection of the second switch.

Abstract: A successive approximation register analog to digital converter (SAR ADC) receives an input voltage and a plurality of reference voltages. The SAR ADC includes a charge sharing DAC. The charge sharing DAC includes an array of MSB (most significant bit) capacitors and an array of LSB (least significant bit) capacitors. A zero crossing detector is coupled to the charge sharing DAC. The zero crossing detector generates a digital output. A coarse ADC (analog to digital converter) receives the input voltage and generates a coarse output. A predefined offset is added to a residue of the coarse ADC. A successive approximation register (SAR) state machine is coupled to the coarse ADC and the zero crossing detector and, generates a plurality of control signals. The plurality of control signals operates the charge sharing DAC in a sampling mode, an error-correction mode and a conversion mode.

Abstract: A delta sigma modulator with an input stage and an output stage. The input stage receives an analog input signal and an output of a first digital to analog converter (DAC). The input stage generates a processed error signal. An additional summation device receives the processed error signal. The output stage receives an output of the additional summation device and generates a delayed digital output signal. A differentiator and the first digital to analog converter (DAC) receive the delayed digital output signal as a feedback signal. A second DAC receives an output of the differentiator and provides an output to an additional negative feedback coefficient multiplier. The additional summation device receives an output of the additional negative feedback coefficient multiplier.

Abstract: A successive approximation register analog to digital converter (SAR ADC) is disclosed. The SAR ADC receives an input voltage and a plurality of reference voltages. The SAR ADC includes a charge sharing DAC. The charge sharing DAC includes an array of MSB (most significant bit) capacitors and an array of LSB (least significant bit) capacitors. A zero crossing detector is coupled to the charge sharing DAC. The zero crossing detector generates a digital output. A coarse ADC (analog to digital converter) receives the input voltage and generates a coarse output. A predefined offset is added to a residue of the coarse ADC. A successive approximation register (SAR) state machine is coupled to the coarse ADC and the zero crossing detector and, generates a plurality of control signals. The plurality of control signals operates the charge sharing DAC in a sampling mode, an error-correction mode and a conversion mode.

Abstract: A delta sigma modulator with an input stage and an output stage. The input stage receives an analog input signal and an output of a first digital to analog converter (DAC). The input stage generates a processed error signal. An additional summation device receives the processed error signal. The output stage receives an output of the additional summation device and generates a delayed digital output signal. A differentiator and the first digital to analog converter (DAC) receive the delayed digital output signal as a feedback signal. A second DAC receives an output of the differentiator and provides an output to an additional negative feedback coefficient multiplier. The additional summation device receives an output of the additional negative feedback coefficient multiplier.