| Patent application number | Description | Published |
|---|
| 20080266009 | Ultra-low power crystal oscillator - An ultra-low power crystal oscillator architecture that draws less than 2 μA during steady state operation. An amplifier stage is self biased and has input and output clamp circuits that limit its signal swing. Circuit values are selected such that there is sufficient transient load current for the first amplifier stage to oscillate, while at the same time the input and output clamp circuits maintain a sufficiently low swing of the stage such that the steady state average load current is on the order of less than 1 μA. | 10-30-2008 |
| 20090168854 | De-Emphasis Circuit for a Voltage Mode Driver Used to Communicate Via a Differential Communication Link - A circuit for de-emphasizing information transmitted via a differential communication link includes a voltage mode differential circuit and a bi-directional current source circuit. The voltage mode differential circuit includes a first and second output terminal. The voltage mode differential circuit provides a first voltage via the first output terminal and second voltage via the second output terminal in response to a differential input voltage. The bi-directional current source circuit is operatively coupled between the first and second terminals. The bi-directional current source circuit selectively provides current in a first and second direction between the first and second terminals based on the first and second voltage. | 07-02-2009 |
| 20100134161 | Phase Detector Circuit for Automatically Detecting 270 and 540 Degree Phase Shifts - Embodiments include implementing a phase detector for a delay-locked loop (DLL) circuit that is operable to detect substantially 270 degree and substantially 540 degree phase differences between two clock signals. In an embodiment, a DLL circuit comprises a delay line receiving a system clock signal and generating a substantially 270 degree phase shifted clock signal and a substantially 540 degree phase shifted clock signal, a phase detector receiving the system clock signal and the substantially 270 degree phase shifted clock signal, and configured to generate corresponding up and down signals upon detection of a phase shift of substantially 270 degrees between the system clock signal and the substantially 270 degree phase shifted clock signal, a charge pump coupled to the phase detector, and configured to receive the up and down signals and generate a control signal responsive to thereto, and a regulator circuit to receive the control signal from the charge pump and generate a voltage control signal to the delay chain to control delay of the system clock signal. | 06-03-2010 |
| 20100238598 | Electrostatic Discharge Power Clamp Trigger Circuit Using Low Stress Voltage Devices - Embodiments of an IC protection circuit that protects low voltage supply transistors and circuits within the IC from excessive power supply levels and ESD events are described. A protection circuit situated between the IO pins of the IC and the internal circuitry of the IC includes a voltage drop network and a plurality of shunt circuits to protect the IC against excessive supply voltages and ESD voltages. Each shunt circuit includes an RC trigger stage and an NMOS shunt stage that are made using low-voltage devices. A protection circuit of the embodiments includes a high voltage IO pin interface, a voltage drop network coupled to the IO pin and comprising a plurality of forward-biased diodes connected in series to drop a high voltage on the IO pin to a low voltage level, an NMOS shunt transistor coupled between the voltage drop network and a ground terminal, and a trigger circuit coupled to the NMOS shunt transistor to activate the shunt transistor when a sensed input voltage rise time is shorter than a defined supply voltage rise time. | 09-23-2010 |
| 20100238599 | Power Supply Equalization Circuit Using Distributed High-Voltage and Low-Voltage Shunt Circuits - Embodiments of an IC protection circuit that protects low voltage supply transistors and circuits within the IC from excessive power supply levels and ESD events are described. A protection circuit situated between the IO pins of the IC and the internal circuitry of the IC includes a voltage drop network and a plurality of shunt circuits to protect the IC against excessive supply voltages and ESD voltages, or other excessive current conditions. Each shunt circuit includes an RC trigger stage and an NMOS shunt stage that are made using low-voltage devices. A protection circuit of the embodiments includes a high voltage IO pin, a voltage drop network to drop a high voltage on the IO pin to a low voltage level on a floating voltage rail, a first shunt circuit coupled between the floating supply rail and ground, an equalizer circuit coupled between the floating supply rail and a low voltage supply rail, and a second shunt circuit coupled to the equalizer circuit through the low voltage supply rail. | 09-23-2010 |
