Abstract:
Integrated Circuits (ICs) comprising circuits configured to generate a power on reset (POR) pulse are disclosed. An IC comprises a power supply sense circuit configured to generate a sense signal in response to a transition of a power supply signal from a first level to a second level, and a pulse generation circuit coupled with the power supply sense circuit. The pulse generation circuit is configured to generate a power on reset (POR) pulse of a threshold duration based on the sense signal. The IC further includes a reset generation circuit coupled with the pulse generation circuit to receive the POR pulse. The reset generation circuit is configured to generate a reset pulse based on the POR signal and of at least one control signal, where the reset pulse is configured to be utilized to perform a reset of one or more elements of the integrated circuit.
Abstract:
An exemplary fast start-up crystal oscillator with reduced start-up time. The exemplary oscillator reduces the start-up time (i.e., the time taken to attain sustained stable oscillations after the power is turned on) by increasing the negative resistance of a circuit. Increasing the negative resistance increases the rate of growth of the oscillations, thereby reducing start-up time. The exemplary crystal oscillator includes a gain stage with negative resistance. A crystal with shunt capacitance is placed in the feedback loop of the gain stage. A buffer is coupled to the gain stage such that it blocks the crystal shunt capacitance from loading the gain stage, effectively increasing the negative resistance of the gain stage. Further, an oscillation detection and control circuit is coupled between the crystal and the gain stage. The oscillation detection and control circuit connects the buffer during start-up, and disconnects the buffer once an oscillation signal attains sustained stable oscillations.
Abstract:
Integrated Circuits (ICs) comprising circuits configured to generate a power on reset (POR) pulse are disclosed. An IC comprises a power supply sense circuit configured to generate a sense signal in response to a transition of a power supply signal from a first level to a second level, and a pulse generation circuit coupled with the power supply sense circuit. The pulse generation circuit is configured to generate a power on reset (POR) pulse of a threshold duration based on the sense signal. The IC further includes a reset generation circuit coupled with the pulse generation circuit to receive the POR pulse. The reset generation circuit is configured to generate a reset pulse based on the POR signal and of at least one control signal, where the reset pulse is configured to be utilized to perform a reset of one or more elements of the integrated circuit.
Abstract:
Integrated Circuits (ICs) comprising circuits configured to generate a power on reset (POR) pulse are disclosed. An IC comprises a power supply sense circuit configured to generate a sense signal in response to a transition of a power supply signal from a first level to a second level, and a pulse generation circuit coupled with the power supply sense circuit. The pulse generation circuit is configured to generate a power on reset (POR) pulse of a threshold duration based on the sense signal. The IC further includes a reset generation circuit coupled with the pulse generation circuit to receive the POR pulse. The reset generation circuit is configured to generate a reset pulse based on the POR signal and of at least one control signal, where the reset pulse is configured to be utilized to perform a reset of one or more elements of the integrated circuit.
Abstract:
An exemplary fast start-up crystal oscillator with reduced start-up time. The exemplary oscillator reduces the start-up time (i.e., the time taken to attain sustained stable oscillations after the power is turned on) by increasing the negative resistance of a circuit. Increasing the negative resistance increases the rate of growth of the oscillations, thereby reducing start-up time. The exemplary crystal oscillator includes a gain stage with negative resistance. A crystal with shunt capacitance is placed in the feedback loop of the gain stage. A buffer is coupled to the gain stage such that it blocks the crystal shunt capacitance from loading the gain stage, effectively increasing the negative resistance of the gain stage. Further, an oscillation detection and control circuit is coupled between the crystal and the gain stage. The oscillation detection and control circuit connects the buffer during start-up, and disconnects the buffer once an oscillation signal attains sustained stable oscillations.
Abstract:
An output buffer receives an input signal and generates an output signal at an output node. The output buffer contains a driver circuit. The driver circuit includes two pairs of cascoded transistors connected at a junction node. Each of the cascoded pairs receives a corresponding level-shifted signal representing the input signal, and generates corresponding driver signals on driver nodes which are coupled to the output node. The driver circuit includes a capacitor connected between one of the driver nodes and the junction node. The capacitor enables the corresponding driver signal to be generated to reach a desired voltage quickly. The output impedance of the output buffer with which the output signal is launched is reduced and more closely matched the impedance of the path on which the output signal is provided. Signal quality of the output signal is thereby improved.
Abstract:
A low voltage crystal oscillator (XTAL) driver with feedback controlled duty cycling for ultra low power biases an amplifier for an XTAL in the sub-threshold operating regime. A feedback control scheme can be used to bias the amplifier for an XTAL biased in the sub-threshold operating regime. The amplifier of a XTAL oscillator can be duty cycled to save power, e.g., the XTAL driver can be turned off to save power when the amplitude of the XTAL oscillation reaches a maximum value in range; but be turned back on when the amplitude of the XTAL oscillation starts to decay, to maintain the oscillation before it stops. In addition or alternatively, a feedback control scheme to duty cycle the amplifier of a XTAL oscillator can be used to monitor the amplitude of the oscillation.
Abstract:
In some embodiments, an apparatus includes a single-inductor multiple-output (SIMO) direct current (DC-DC) converter circuit, with the SIMO DC-DC converter circuit having a set of output nodes. The apparatus also includes a panoptic dynamic voltage scaling (PDVS) circuit operatively coupled to the SIMO DC-DC converter circuit, where the PDVS circuit has a set of operational blocks with each operational block from the set of operational blocks drawing power from one supply voltage rail from a set of supply voltage rails. Additionally, each output node from the set of output nodes is uniquely associated with a supply voltage rail from the set of supply voltage rails.
Abstract:
In some embodiments, an apparatus includes a single-inductor multiple-output (SIMO) direct current (DC-DC) converter circuit, with the SIMO DC-DC converter circuit having a set of output nodes. The apparatus also includes a panoptic dynamic voltage scaling (PDVS) circuit operatively coupled to the SIMO DC-DC converter circuit, where the PDVS circuit has a set of operational blocks with each operational block from the set of operational blocks drawing power from one supply voltage rail from a set of supply voltage rails. Additionally, each output node from the set of output nodes is uniquely associated with a supply voltage rail from the set of supply voltage rails.
Abstract:
An ultra-low power clock source includes a compensated oscillator and an uncompensated oscillator coupled by a comparator circuit. In an example, the compensated oscillator is more stable than the uncompensated oscillator with respect to changes in one or more of temperature, voltage, age, or other environmental parameters. The uncompensated oscillator includes a configuration input configured to adjust an operating characteristic of the uncompensated oscillator. In an example, the uncompensated oscillator is adjusted using information from the comparator circuit about a comparison of output signals from the compensated oscillator and the uncompensated oscillator.