Etron Technology, Inc.

Jenshou Hsu

Tah-Kang Joseph Ting

A method and apparatus are provided for improving the efficiency in charge pump systems for low power applications. This first embodiment provides a method and apparatus which defines a charge pump output voltage high target which turns off a charge pump enable signal and a charge pump outlet voltage low target which turns on a charge pump enable signal. A second embodiment defines a protection time where the charge pumping continues until a predefined phase is completed and the leakage paths are disabled. A third embodiment defines a phase memory block, which continues or remembers the phase until the next request for charge pumping. This prevents the circuitry from entering a window where charge leakage, which diminishes charge pumping efficiency, could occur.

Efficiency improvement in charge pump system for low power application

Methods and circuits for chain ring oscillators having a constant delay time over variations of temperature and variations of semiconductor manufacturing process while requiring low operating voltage only have been disclosed. A system current source includes a constant voltage circuit generating a constant voltage and hence a constant current via a resistance element. Main parts of the constant voltage circuit are an operational amplifier and a bandgap reference circuit. Using a series of current mirrors the constant currents are mirrored to current sources contained in each of n-inverter stages of the chain ring oscillator.

Low voltage operating ring oscillator with almost constant delay time

A PTAT biasing circuit for use in a bandgap referenced voltage source includes a startup sub-circuit. Prior to activation of a power up indication signal, the speedup circuit forces the PTAT biasing circuit from a degenerate operating point to a normal operating point. Upon detection of a feedback signal denoting the initiation of the PTAT biasing circuit, the startup sub-circuit terminates operation of the startup sub-circuit independent of the activation of the power up indication signal.

Speed-up circuit for initiation of proportional to absolute temperature biasing circuits

A temperature sensor with a plurality of temperature sense points based on a bandgap reference circuit providing negative temperature coefficient reference voltages and a positive temperature coefficient reference voltage. All negative temperature coefficient reference voltages have the same slope and the same spacing from each other. The intercept points between the negative temperature coefficient reference voltages and the positive temperature coefficient reference voltage determine the temperature sense points. Efficient calibration of the spacing of the temperature sense points is provided by a tap on a programmable resistor in the positive temperature coefficient reference circuit. Efficient calibration of the absolute temperature is provided by second programmable resistors in a circuit driven by two current sources. The calibration of one temperature point equally applies to all other second programmable resistors.

Precise temperature sensor with smart programmable calibration

A low voltage bandgap reference circuit based on a current summation technique where reference voltages with positive and negative temperature coefficients are generated by a first circuit. These reference voltages are coupled to amplifying circuits which generate reference voltages with equal and opposite temperature coefficients based on the ratio of resistors in these amplifying circuits, thereby producing a temperature independent reference voltage. The current from each of these amplifying circuits is then summed in a summing resistor, where the size of the resistor determines the magnitude of the temperature independent reference voltage.

Low voltage bandgap reference (BGR) circuit

A circuit and a method are provided for sensing integrated circuit temperatures using low power and small area. This temperature sensor is more accurate than other temperature sensors, since it uses a reference voltage which has a steeper slope versus temperature. Also, this temperature sensor dissipates lower power than conventional designs, since it only requires two voltage comparators. This is accomplished via a unique transfer gate voltage selection system, which allows two comparators to be reused during different temperature control state modes. The simple design can be scaled to add to the number of temperatures to be detected.

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Hsin-Chu, Taiwan

Jenshou Hsu