US 9,178,497 B2Granted

Precision oscillator with temperature compensation

AssigneeMarvell World Trade Ltd.

InventorsDennis Sinitsky, Tao Shui

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Abstract

New and highly stable oscillators are disclosed. Such an oscillator may include a first capacitor electrically connected to a first charging switch and a first discharging switch, a second capacitor electrically connected to a second charging switch and a second discharging switch, a first chopping circuit having a first input electrically connected to the first capacitor and a second input electrically connected to a reference voltage, a second chopping circuit having a first input electrically connected to the second capacitor and a second input electrically connected to the reference voltage, a first comparator having a first input electrically connected to a first and second output of the first chopping circuit, a second comparator having a first input electrically connected to a first and second output of the second chopping circuit, and control circuitry having a first input electrically coupled to an output of the first comparator and a second input electrically connected to an output of the second comparator.

Claims15

Dependent claims

A method of controlling an oscillator, comprising:

comparing a first voltage and a reference voltage in a first comparator to determine a first input offset voltage;
comparing a second voltage with the reference voltage in a second comparator to determine a second input offset voltage;
compensating for a difference between the first input offset voltage of the first comparator and second input offset voltage of the second comparator by connecting a first input of the first comparator to the first voltage and a second input of the first comparator to the reference voltage when a control signal is at a first state, and connecting the first input of the first comparator to the reference voltage and the second input of the first comparator to the first voltage when the control signal is in a second state;
controlling an oscillation of the oscillator based on the compensated differences in the respective first and second input offset voltages by control circuitry having one or more logic gates receiving output signals from the two comparators;
performing an exclusive-or (XOR) operation between an output of the first comparator and the control signal by a first XOR gate of the one or more logic gates, the first XOR gate having inputs electrically connected to the output of the first comparator and the control signal;
and
performing another XOR operation between an output of the second comparator and a second control signal by a second XOR gate of the one or more logic gates, the second XOR gate having inputs electrically connected to the output of the second comparator and the second control signal.

4 more elements

An oscillator, comprising:

a capacitor circuit;
a first circuit having a first input electrically connected to the capacitor circuit and a second input electrically connected to a reference voltage, the first circuit including a switching network that connects its first input to its first output and its second input to its second output when a control signal is at a first state, and connects its first input to its second output and its second input to its first output when the control signal is at a second state;
a second circuit having a first input electrically connected to the capacitor circuit and a second input electrically connected to the reference voltage;
a first comparator having a first input and second input electrically connected to the first output and second output of the first circuit;
a second comparator having a first input and second input electrically connected to a first output and second output of the second circuit;
and
control circuitry having one or more logic gates receiving output signals from the two comparators, the one or more logic gates including:
a first exclusive-or (XOR) gate having inputs electrically connected to an output of the first comparator and the control signal;
and
a second XOR gate electrically having inputs electrically connected to an output of the second comparator and a second control signal.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/218,256Filed 18 Mar 2014 · continuation
Priority: 19 Jan 2011
Published: US 2014/0197897 A117 Jul 2014
Granted: 3 Nov 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H03K 3/02
Circuits for generating electric pulses; Monostable, bistable or multistable circuits: generators characterised by the type of circuit or by the…
H03K 3/011
Details: modifications of generator to compensate for variations in physical values, e.g. voltage, temperature
H03K 3/0231
By the use of differential amplifiers or comparators, with internal or external positive feedback: astable circuits
H03K 4/502
The starting point of the flyback period being determined by the amplitude of the voltage across the capacitor, e.g. by a comparator: the…

Family

Application61/434,292Us provisional application · filed 19 Jan 2011
Application13/350,229Parent of this continuation · filed 13 Jan 2012
US 2014/0197897 A1Pre-grant publication · published 17 Jul 2014
US 8,692,625 B2Parent of this continuation
US 2012/0182080 A1Published application
US 9,178,497 B2This patent

From the US filing history. Foreign family members aren’t listed.