Abstract: An auto-nulled bandgap reference system employing a substrate bandgap reference circuit with primary and auxiliary amplifiers and a switching circuit which in a first mode develops a voltage to null the offset and noise errors of the auxiliary amplifier and then in the second mode uses the nulled auxiliary amplifier to develop a voltage to null the offset and noise errors of the primary amplifier; and a strobe circuit including an output storage device and a strobe control circuit for periodically powering up a bandgap reference circuit to charge the output storage device and powering down the bandgap reference circuit to conserve power.

Abstract: A balanced, differential, cross-coupled amplifier including an input stage for receiving a differential input and including an input transconductance differential pair and a feedback transconductance differential pair; and an output stage responsive to the input stage for providing a differential output; the differential input being connected to one input of the input transconductance differential pair and one input of the feedback transconductance differential pair, the differential output being fed back to one input of the input transconductance differential pair and one input of the feedback transconductance differential pair for balancing the currents in the transconductance differential pairs over the input range.

Abstract: A sensor device formed on a semiconductor substrate. The device comprises a thermal radiation sensor including a sensing cell and a referencing cell which are co-operable for providing a first output signal indicative of the temperature fluctuation resulting from incident radiation. A gradient sensor including a pair of cells spatially located on the semiconductor substrate is provided which are co-operable to provide a second output signal indicative of the temperature gradient across the semiconductor substrate for facilitating calibrating the first output signal. At least one of the cells of the gradient sensor is not common to the cells of the thermal radiation sensor.

Abstract: A system and method of widening the synchronization range for a discrete multitone multicarrier single pilot tone system includes detecting a first phase error in a received pilot tone; detecting a second phase error in a received second two bit constellation data channel; converting the second phase error to a first quadrant angle between 0-90° and combining the first phase error and the converted phase error to obtain the actual phase error up to and beyond 360°.

Abstract: An output driver in an integrated circuit includes a driver circuit operable by a power supply voltage and coupled to an output pad, and a driver power conditioner configured to generate a fractional pad voltage in response to a voltage on the output pad and to provide the fractional pad voltage to at least one transistor of the driver circuit as a protected supply voltage in response to an absence of the power supply voltage.

Abstract: A differential current output driver and a method for overvoltage protection of a differential current output driver circuit are provided. The output driver includes a differential current output driver circuit operable by a power supply voltage and including first and second driver transistors in a differential current configuration and first and second output pads, and an overvoltage protection circuit configured to generate a protected voltage in response to a voltage on at least one of the first and second output pads and an absence of the power supply voltage, and to apply the protected voltage to at least one transistor of the differential current output driver circuit.

Abstract: In one aspect, an automatic gain control (AGC) for applying a variable gain to a broadband signal is provided. The AGC comprises a variable gain amplifier adapted to receive the broadband signal as an input, the variable gain amplifier configured to apply a variable gain to the broadband signal based on a value of a gain signal to provide an amplified broadband signal, and a controller to provide the gain signal to the variable gain amplifier, the controller adapted to determine the value of the gain signal based on at least one characteristic of the amplified broadband signal. In a further aspect, the one or more characteristic is a power characteristic of the broadband signal that facilitates control of the broadband signal within a desired power range.

Abstract: A bandgap voltage reference circuit is provided that includes a PTAT source whose polarity reverses at a determinable temperature. The PTAT source is combined with a CTAT source in a manner to remove the effects of the slope of the CTAT source such that a voltage reference may be generated. A method of operating such a circuit is also described.

Abstract: Clock generator embodiments are provided to generate half-rate I and Q clock signals. The generators are configured to insure fan-out limitations, to insure correct phasing at startup, to reduce the number of signal inverters in a critical path, and to reduce the total number of inverter structures to thereby substantially extend generator operational frequency. An exemplary generator embodiment requires only two tri-state inverters and four inverters. These clock generators are particularly suited for variety of electronic systems such as high speed data serializers.

Abstract: An apparatus, method, and article to dynamically adjust a data signal using a regenerated clock signal in an emulator to increase communication speed between the emulator and the evaluation board is disclosed. In one embodiment, this is achieved by applying a reference clock signal at a predetermined frequency to a digital circuit. A delayed return data signal is then sampled from the digital circuit. The sampled delayed return data signal is then compared to an expected return data signal. The delayed return data signal is then adjusted as a function of the comparison to increase the communication speed between the emulator and the evaluation board.

Abstract: A microprocessor to provide software development debugging capabilities while providing security for confidential and/or sensitive information. The processor may operate in one of an open, a secure entry, and a secure mode. In open mode, security measures may prevent access to certain registry bits and access to a private memory area. Secure entry mode may be entered upon receipt of a request to run secure code and/or access the private memory area. The secure code may be authenticated in secure entry mode. Authentication may be performed using digital signatures. Secure mode may be entered if authentication is successful. Authenticate code may be executed in the secure mode environment. The private memory area may be accessible in secure mode.

Abstract: A MEMS microphone has an SOI wafer, a backplate formed in a portion of the SOI wafer, and a diaphragm adjacent to and movable relative to the backplate. The backplate has at least one trench that substantially circumscribes a central portion of the backplate.

Abstract: A method and apparatus for protecting access to sensitive information stored in vulnerable storage areas (e.g., public memory, registers, cache) of a microprocessor. A microprocessor having a reset port to receive external reset commands may have a reset diversion circuit that may be selectively enabled. The microprocessor may operate in an open mode or a secure mode, indicating the absence or the potential presence, respectively, of sensitive information in the vulnerable storage areas. In open mode, the reset diversion circuit may be disabled such that external reset requests triggers a hardware reset. In secure mode, sensitive information may be recorded on vulnerable storage areas. The reset diversion circuit may be enabled to divert external reset requests to an interrupt which may trigger execution of a software code. The software code, when executed, may perform a secured system clean-up routine to erase the vulnerable storage areas prior to reset.

Abstract: A measurement signal from a detector may have a complementary polarity. For example, an RF power detector may generate an output signal that decreases in magnitude in response to an increasing input signal. In one embodiment, the RF power detector may include a series of transconductance detector cells arranged to progressively turn off as the input signal becomes progressively larger.

Abstract: A voltage level translator provides an output signal having an external voltage in response to an input signal having an internal voltage. The voltage level translator includes first and second input signal transistors, first and second output signal transistors, and includes a signal stabilization circuit and/or an enable circuit. A ready-signal generation circuit provides a ready signal indicating that a voltage supply is at an operating voltage. The ready-signal generation circuit can include unbalanced transistors.

Abstract: Disclosed are a circuit and a method for tuning a programmable filter including input terminals, output terminals, a filter network and a transadmittance stage. The input terminals can receive input signals, and the output terminals output a filtered signal. The transadmittance stage, coupled to the input terminals, generates a current at its output based on the input signals. The output of the transadmittance stage can be coupled to the output terminals. The filter network can be a resistive-capacitive network connected to the input terminals. The RC network can include a capacitance respectively coupling the input terminals to output terminals, and a voltage divider network coupling the input and output terminals together. The transadmittance stage output terminals can be connected to the voltage divider, and the output terminals of the programmable filter circuit are coupled to respective intermediate nodes of the voltage divider network to provide a filtered output signal.

Abstract: A multi-channel circuit includes a first-channel circuit configured to receive a digital input and a second-channel output voltage, and to generate a first-channel output voltage as a function of the received digital input and second-channel output voltage.

Abstract: A switched-capacitor circuit includes a plurality of cascaded differential-input, single-ended-output amplifiers. A negative feedback path, from an output terminal of a last of the cascaded amplifiers to an input terminal of a first of the cascaded amplifiers, is configured to exclude, and not be shorted out by, any switches.

Abstract: A common mode rejection calibration scheme for use with a difference amplifier having an associated signal path. A signal is generated which varies with the common mode voltage of the differential input voltage applied to the amplifier. This signal is scaled and coupled into the signal path such that the scaled signal reduces the common-mode error that would otherwise be present in the difference amplifier's output.

Abstract: The invention comprises a hardware constructed address generator for a circular buffer which can be of any size and be in any position in memory. The address generator calculates both an absolute value and a wrapped value and selects one in accordance with whether the wrapped value falls within the boundaries of the buffer.