Temperature-compensated oscillator and device including the same

• US 9,900,015 B2
• Filed: 08/11/2016
• Issued: 02/20/2018
• Est. Priority Date: 10/30/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Jun Ho, Cho, Jong Pil
• Primary Examiner(s): Tan, Richard
• Application Number:
  US15/234,098
• Publication Number:
  US 20160352339A1
• Time in Patent Office: 558 Days
• Field of Search: 331 57, 331 66, 331176, 331185, 331186
• CPC Class Codes: H03K 3/011 Modifications of generator to compensate for variations in physical values, e.g. voltage, temperature to maintain energy constant H03K3/015
• CPC Class Codes: H03K 3/0315 Ring oscillators
• CPC Class Codes: H03L 1/02 against variations of temperature only
• CPC Class Codes: H03L 1/022 by indirect stabilisation, i.e. by generating an electrical correction signal which is a function of the temperature H03L1/021 takes precedence
• CPC Class Codes: H03L 5/00 Automatic control of voltage, current, or power

Abstract

A temperature-compensated oscillator and a device including the same include an oscillation unit configured to generate an oscillation signal using an operating current and an operating voltage, a bias circuit configured to control the operating current so that a frequency of the oscillation signal increases as a temperature increases, and a voltage generation unit configured to generate the operating voltage that varies with the temperature.

Claims

1. A temperature-compensated oscillator comprising:

an oscillation circuit configured to generate an oscillation signal and including an odd number of inverters connected in series;

a bias circuit configured to increase an operating current of the inverters as a temperature increases;

a current mirror circuit connected to the bias circuit, and configured to mirror the operating current of the inverters; and

a voltage generator including;

a first operating current generation transistor connected between a supply voltage and a first operating voltage and connected to the oscillation circuit;

or

a second operating current generation transistor connected between a ground and a second operating voltage and connected to the oscillation circuit,

wherein the current mirror circuit is connected to the first operating current generation transistor or the second operating current generation transistor,

wherein the inverters are connected to the first operating voltage or the second operating voltage,

wherein the first operating voltage of the inverters is configured to increase or decrease as the temperature increases, and

wherein each of the first and second operating current generation transistors has a diode connection.

2. The temperature-compensated oscillator of claim 1, wherein the inverters are connected in a ring shape.

3. The temperature-compensated oscillator of claim 1, wherein each of the first operating current generation transistor and the second operating current generation transistor is configured to change the first operating voltage of the inverters based on the temperature.

4. The temperature-compensated oscillator of claim 1, wherein a frequency of the oscillation signal is higher in a normal mode than in a non-normal mode, which is one of an ultra-low current mode, a standby mode, or a sleep mode.

5. The temperature-compensated oscillator of claim 1, wherein the bias circuit is configured to increase the operating current of the inverters when the temperature increases.

6. The temperature-compensated oscillator of claim 1, wherein the first operating voltage is VDD, and the second operating voltage is VSS.

7. The temperature-compensated oscillator of claim 1, wherein the oscillation circuit includes either a first current source that is connected between the first operating voltage and the inverters and is controlled by the bias circuit, or a second current source that is connected to the inverters and the second operating voltage and is controlled by the bias circuit.

8. A temperature-compensated oscillator comprising:

an oscillation circuit configured to generate an oscillation signal and including an odd number of inverters that are connected in series and connected in a ring shape;

a bias circuit configured to increase an operating current of the inverters as a temperature increases;

a current mirror circuit connected to the bias circuit, and configured to mirror the operating current of the inverters; and

a voltage generator configured to generate a first operating voltage or a second operating voltage for each of the inverters based on the temperature, the voltage generator including;

a first operating voltage generation transistor connected between a supply voltage and the first operating voltage and connected to the oscillation circuit;

or

a second operating voltage generation transistor connected between a ground and the second operating voltage and connected to the oscillation circuit,

wherein the current mirror circuit is connected to the first operating voltage generation transistor or the second operating voltage generation transistor,

wherein the inverters are connected to the first operating voltage or the second operating voltage, and

wherein the first operating voltage of the inverters is configured to increase or decrease as the temperature increases.

9. The temperature-compensated oscillator of claim 8, wherein the bias circuit includes:

a first transistor having a gate and a drain connected in common to a first node;

a second transistor having a gate and a drain connected in common to a second node;

a third transistor having a gate connected to the second node and a drain connected to a third node;

a fourth transistor having a source connected to the supply voltage, a gate connected to the third node, and a drain connected to the second node;

a fifth transistor having a gate and a drain connected in common to the third node and a source connected to the supply voltage; and

a sixth transistor having a gate connected to the third node, a source connected to the supply voltage, and a drain connected to the first node.

10. The temperature-compensated oscillator of claim 8, wherein an association of the first operating voltage and the operating current reduces a variation of a frequency of the oscillation signal.

11. The temperature-compensated oscillator of claim 8, wherein the voltage generator includes a bulk voltage controller configured to control a bulk voltage of the first operating voltage generation transistor and/or the second operating voltage generation transistor.

12. The temperature-compensated oscillator of claim 8, wherein the first operating voltage is different from the supply voltage, and or the second operating voltage is different from the ground.

13. The temperature-compensated oscillator of claim 8, wherein the voltage generator is configured to generate the first operating voltage or the second operating voltage, using the supply voltage.

14. The temperature-compensated oscillator of claim 8, wherein a frequency of the oscillation signal is higher in a normal mode than in a non-normal mode, which is one of an ultra-low current mode, a standby mode, or a sleep mode.

15. A temperature-compensated oscillator comprising:

an oscillation circuit configured to generate an oscillation signal using an operating current and an operating voltage;

a bias circuit configured to control the operating current so that a frequency of the oscillation signal increases as a temperature increases; and

a voltage generator configured to generate the operating voltage that varies with the temperature, the voltage generator including an operating voltage generation transistor,

wherein the voltage generator compensates for a change in the frequency of the oscillation signal with respect to a change of the temperature complementarily with the bias circuit by controlling the operating voltage so that the frequency of the oscillation signal decreases as the temperature increases, and

wherein the frequency of the oscillation signal is higher in a normal mode than in a non-normal mode, which is one of an ultra-low current mode, a standby mode, or a sleep mode.

16. The temperature-compensated oscillator of claim 15, wherein the operating voltage generation transistor includes a first operating current generation transistor connected to a supply voltage or a second operating current generation transistor connected to a ground.

17. The temperature-compensated oscillator of claim 15, wherein the oscillation circuit is configured to generate the oscillation signal with frequencies to be usable in corresponding different modes based on the operating voltage and/or based on the operating current.

18. The temperature-compensated oscillator of claim 15, wherein the operating current is a nano-current.