US 7,889,016 B2 · Integrated RC oscillator with high frequency stability, notably for an integrated switched-mode power supply

Abstract

An integrated oscillator (10), for an integrated circuit, comprises i) first (CI1) and second (CI2) compensated inverters mounted in series and each comprising first (PI11;PI21) and second (PI12;PI22) plain inverters mounted in parallel and comprising transistors having channel lengths respectively shorter and longer than an optimal channel length, the first compensated inverter (CI1) having input and output terminals respectively connected to first (N1) and second (N2) nodes and the second compensated inverter (CI2) having input and output terminals respectively connected to the second node (N2) and to a third node (N3), ii) a resistor (R) having a chosen resistance value and comprising first and second terminals connected respectively to the first (N1) and second (N2) nodes, and iii) a capacitor (C) comprising first and second terminals connected respectively to the first (N1) and third (N3) nodes, and having a chosen capacitance value to charge and discharge oneself in order to periodically deliver a clock signal at the desired oscillation frequency.

Claims16

Dependent claims

An integrated oscillator, comprising:

a first compensated inverter having input and output terminals respectively connected to first and second nodes, the first compensated inverter including a first plain inverter and a second plain inverter coupled in parallel to each other, the first plain inverter having a channel length that is shorter than a channel length of the second plain inverter;
a second compensated inverter having input and output terminals respectively connected to said second node and to a third node, the second compensated inverter including a third plain inverter and a fourth plain inverter coupled in parallel to each other, the third plain inverter having a channel length that is shorter than a channel length of the fourth plain inverter;
a resistor having a resistance value and comprising first and second terminals connected respectively to said first and second nodes;
and
a capacitor comprising first and second terminals connected respectively to said first and third nodes, and having a capacitance value, the inverters, resistor, and capacitor being configured to deliver a clock signal at the third node at an oscillation frequency.

2 more elements

An integrated switched-mode power supply, comprising:

a DC-DC converter comprising a first input configured to receive an input DC voltage, a second input, and an output configured to deliver an output DC voltage;
and
an integrated oscillator configured to deliver a clock signal and an oscillation frequency on an oscillator output that is coupled to the second input of the DC-DC converter, the oscillator including:
a first compensated inverter having input and output terminals respectively connected to first and second nodes, the first compensated inverter including a first plain inverter and a second plain inverter coupled in parallel to each other, the first plain inverter having a channel length that is shorter than a channel length of the second plain inverter;
a second compensated inverter having input and output terminals respectively connected to said second node and to a third node coupled to the oscillator output, the second compensated inverter including a third plain inverter and a fourth plain inverter coupled in parallel to each other, the third plain inverter having a channel length that is shorter than a channel length of the fourth plain inverter;
a resistor having a resistance value and comprising first and second terminals connected respectively to said first and second nodes;
and
a capacitor comprising first and second terminals connected respectively to said first and third nodes, and having a capacitance value.

5 more elements

An electronic device, comprising:

a battery arranged to deliver an input DC voltage;
an integrated switched-mode power supply arranged to convert said input DC voltage into an output DC voltage, and
a circuit configured to be powered by said output DC voltage, said integrated switched-mode power supply includes:
a DC-DC converter comprising a first input configured to receive the input DC voltage, a second input, and an output configured to deliver the output DC voltage;
and
an integrated oscillator configured to deliver a clock signal and an oscillation frequency on an oscillator output that is coupled to the second input of the DC-DC converter, the oscillator including:
a first compensated inverter having input and output terminals respectively connected to first and second nodes, the first compensated inverter including a first plain inverter and a second plain inverter coupled in parallel to each other, the first plain inverter having a channel length that is shorter than a channel length of the second plain inverter;
a second compensated inverter having input and output terminals respectively connected to said second node and to a third node coupled to the oscillator output, the second compensated inverter including a third plain inverter and a fourth plain inverter coupled in parallel to each other, the third plain inverter having a channel length that is shorter than a channel length of the fourth plain inverter;
a resistor having a resistance value and comprising first and second terminals connected respectively to said first and second nodes;
and
a capacitor comprising first and second terminals connected respectively to said first and third nodes, and having a capacitance value.

8 more elements

Dependencies are inferred from the claim text.

Integrated RC oscillator with high frequency stability, notably for an integrated switched-mode power supply

Life of this patent

Integrated RC oscillator with high frequency stability, notably for an integrated switched-mode power supply

Life of this patent

Abstract

Claims16