Offset cancellation for sampled-data circuits
Granted: August 27, 2013
Patent Number:
8519769
A comparator based circuit with effective offset cancellation includes first and second amplifiers and an offset capacitor operatively connected to the first and second amplifiers. An offset voltage source generates an offset voltage. A first switch connects the offset voltage source to ground during a first time period. The first amplifier generates an output voltage in response to the first switch connecting the offset voltage source to ground during the first time period. A second…
Secure processor for extreme outdoor temperature conditions
Granted: August 27, 2013
Patent Number:
8522049
If the temperature of a secure device falls below a second temperature, then sensitive information is automatically erased from a secure memory. To allow the secure device to operate in very cold ambient temperatures that are below the second temperature, a novel heater circuit is provided. If the temperature of the secure device drops below a first temperature, then the heater heats the secure processor. If AC power is lost, such as in a power outage, energy for the heater is provided…
Keypad having tamper-resistant keys
Granted: August 20, 2013
Patent Number:
8513548
A tamper resistant keypad includes one or more key assemblies having a resilient key member and a contact. The resilient key member is configured to flex when the key assembly is depressed to allow the contact to close a key press detection circuit on a circuit board to register a key press. A tamper detection switch assembly at least partially surrounds the resilient key member. The tamper detection switch assembly is configured to detect attempts to access the key assembly.
Systems for comparator offset cancellation in successive-approximation-register analog-to-digital converters
Granted: August 13, 2013
Patent Number:
8508398
A system for a successive-approximation-register analog-to-digital-converter (SAR ADC) includes a first capacitive digital-to-analog converter (DAC), first and second conversion control modules, and an SAR control module. The first capacitive DAC has a size less than a second DAC of the SAR ADC. The first conversion control module generates first and second signals for a comparator of the SAR ADC based on outputs of the first and second capacitive DACs and an analog input signal. The…
Multi-bus architecture for a video codec
Granted: August 6, 2013
Patent Number:
8503534
Embodiments of the present invention relate to a multi-bus architecture within a video codec that discretely and efficiently transports video components within the codec. This multi-bus architecture provides a relatively more efficient transport mechanism because the various buses are designed to specifically address unique characteristics of the video components or parameters being processed within the codec.
Model-based battery fuel gauges and methods
Granted: August 6, 2013
Patent Number:
8502504
Model-based battery fuel gauges that connect across a rechargeable battery and track the per-cent state of charge of the battery. The model based fuel gauges provide a measure of the open terminal voltage of a battery, even when the battery is powering a load, to provide the state of charge information. Analog and digital implementations of the battery model fuel gauges may be used, and incorporated into a battery powered device in various ways, including constantly powered…
High speed digital-to-analog converter with low voltage device protection
Granted: July 30, 2013
Patent Number:
8498086
A digital-to-analog converter (DAC) includes a first DAC core, a second DAC core, and a butterfly switch. The first DAC core generates a first output. The second DAC core generates a second output. The butterfly switch includes at least one of switch transistors and cascode transistors. The butterfly switch selectively connects the first output and the second output to an output stage of the DAC.
Noise cancellation technique for capacitive touchscreen controller using differential sensing
Granted: July 23, 2013
Patent Number:
8493356
A differential sensing scheme provides a means for detecting one or more touch events on a touch sensitive device in the presence of incident noise. Instead of sensing one touch sensitive channel, such as a row, column, or single touch sensor, multiple touch sensitive channels are sampled at a time. By sampling two nearby channels simultaneously and doing the measurement differentially, noise common to both channels is cancelled. The differential sensing scheme is implemented using…
Shunt sensor and shunt sensor assembly
Granted: July 23, 2013
Patent Number:
8493059
The present disclosure describes configurations for current shunt sensors and current shunt sensor assemblies having improved electromagnetic cross-talk rejection that can be used in single-phase/split-phase and poly-phase power metering applications. Some embodiments of the current shunt sensors and current shunt sensor assemblies reduce the need for a shielding material around current shunt sensors in single-phase/split-phase and poly-phase power metering applications. Some embodiments…
Data interface with delay locked loop for high speed digital to analog converters and analog to digital converters
Granted: July 16, 2013
Patent Number:
8488657
A system comprises a first circuit includes a data transmitter circuit that transmits digital data based on a first clock signal. A sync generator outputs a sync signal based on the first clock signal. A digital to analog converter circuit includes a data receiver circuit that latches the digital data based on a second clock signal. A digital to analog converter core receives an output of the data receiver circuit. A delay locked loop circuit determines a delay based on the second clock…
Deep trench capacitor with conformally-deposited conductive layers having compressive stress
Granted: July 16, 2013
Patent Number:
8487405
A high density deep trench MIM capacitor structure is provided wherein conductive-compressive-conformally applied layers of a semiconductor material, such as a Poly-SixGe1-x, are interleaved within MIM capacitor layers to counterbalance the tensile stresses created by such MIM capacitor layers. The interleaving of conductive-compressive-conformally applied material layers are adapted to counterbalance convex (upward) bowing of silicon wafers during the manufacturing process of high…
Microgyroscope for determining rotational movements about an X and/or Y and Z axis
Granted: July 9, 2013
Patent Number:
8479575
The invention relates to a microgyroscope for determining rotational movements about an x-axis and/or a y-axis and a z-axis. Oscillating masses are fastened to a substrate by springs. Drive elements vibrate individual masses in an oscillatory manner in the x-y plane in order to produce Coriolis forces when the substrate is rotated, and sensor elements detect deflections of the masses on account of the Coriolis forces produced. The Individual masses are arranged in two groups that are…
Headphone driver/charge pump combination
Granted: July 2, 2013
Patent Number:
8476978
A headphone driver amplifier operative without an external negative voltage power supply, coupled directly to the headphone speakers without the need for DC coupling capacitors used for preventing DC reaching the headphones. An onboard power supply generates a negative voltage rail which powers the output amplifiers, allowing driver amplifier operation from both positive and negative rails. Since the amplifiers can be biased at ground potential (O volts), no significant DC voltage exists…
Jammer canceller for power-line communication
Granted: June 25, 2013
Patent Number:
8472576
An apparatus to process an input signal received via a power line in a power line communication system includes a jammer remover and a jammer detector. The jammer remover removes interference resulting from transmission of electricity and the input signal over the power line from the input signal. The jammer remover generates a jammer-canceled signal using an adaptive filtering procedure. The jammer detector is coupled to the jammer remover to detect the interference.
Active transducer probes and circuits
Granted: June 18, 2013
Patent Number:
8465432
In an example embodiment, a method for bidirectional signal propagation comprises: a) sensing a voltage level of a first signal at a first port; b) coupling the first port to an output of an amplifier with a solid state switch if the voltage level of the first signal is less than a threshold voltage, whereby a second signal applied to a second port coupled to an input of the amplifier is propagated in a first direction from the second port to the first port; and c) bypassing the…
Method and apparatus for generating a target frequency having an over-sampled data rate using a system clock having a different frequency
Granted: June 4, 2013
Patent Number:
8456344
Method and apparatus for generating a target frequency having an over-sampled data rate using a system clock having a different frequency are disclosed. In one aspect of the present disclosure, the circuit includes, a digital phase locked loop coupled to the system clock. The digital phase locked loop including an oscillator output and an oscillator input. The circuit further comprises an extra pulse eliminator coupled to the oscillator output. The extra pulse eliminator includes an…
Systems and methods for controlling inductive energy in DC-DC converters
Granted: May 28, 2013
Patent Number:
8450988
A DC-DC converter comprises a high-side switch, a low-side switch connected to the high-side switch, and an output capacitance. An inductance has one end connected to the high-side switch and the low-side switch and another end connected to the output capacitance. A shunting device circulates current flowing through the inductance back to the inductance during a load reduction transition to control a voltage across the output capacitance.
Bandgap curvature correction circuit for compensating temperature dependent bandgap reference signal
Granted: May 21, 2013
Patent Number:
8446141
A temperature compensated bandgap reference circuit includes a bandgap voltage generator having a temperature dependent signal output and a correction circuit coupled to the output of the bandgap voltage generator and generating a second order quadratic signal which is complementary to the signal output.
Method to reduce voltage swing at comparator input of successive-approximations-register analog-to-digital converters
Granted: May 14, 2013
Patent Number:
8441386
A SAR ADC includes a DAC including a first set of capacitors each having a first end connected to a common node, and a second end, and a first set of switches each connecting the second end of a respective one of the capacitors to a first reference voltage. The SAR ADC further includes a second set of capacitors each having a first end connected to the common node and a second end that receives an input to be converted when the common node is connected to ground. The SAR ADC further…
Digital correction of analog polyphase filters
Granted: May 14, 2013
Patent Number:
8442171
Embodiments of the present invention provide systems, devices and methods for modeling and correcting amplitude and quadrature phase errors generated within analog components of a receiver. A frequency-dependent correction method is employed that closely tracks the frequency dependent nature of the mismatch between the I and Q polyphase filter responses. In particular, digital correction is performed on a signal based on a modeled error function generated during a calibration of the…
