# US 2008/0303601 A1 · Reference oscillator and its use > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0303601 A1 - Document ID: US20080303601A1 - Status: Published application - Kind: A1 - Application number: 12/130,271 - Filed: 2008-05-30 - Published: 2008-12-11 - Earliest claimed: 2007-06-01 - Assignees: Nemerix SA - Inventors: Phil YOUNG - Web page: https://patentgrep.com/patent/US20080303601A1 ## CPC - H03L 1/028: {of generators comprising piezoelectric resonators (H03L1/021, H03L1/022 take precedence; oscillation generators with a piezoelectric resonator H03B5/32)} - G01S 19/34: Power consumption - G01S 19/35: Constructional details or hardware or software details of the signal processing chain - H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A reference clock circuit (170), has a low-power mode, in which the frequency consumption is reduced, and including an internal counter, accumulating time spent in low-power mode. The circuit includes a crystal resonator (60), an oscillator circuit (70), and a temperature compensation circuit (80), providing a stable clock output (85). During low-power mode temperature compensation can be switched off. The circuit further provides a wakeup signal (107) after a preset time in low-power mode. ## Claims ### Claim 1 A reference oscillator circuit, including: a crystal resonator, having a resonance frequency; an oscillator arranged to maintain the resonator in oscillation at the resonance frequency, and generate an oscillating signal at the resonance frequency, a temperature compensation circuit, providing a temperature-compensated clock output signal, wherein the reference circuit has at least one normal operational state and a low-power state, wherein the power consumption of the reference circuit in the low-power state is lower than the power consumption of the reference circuit in the normal state, and a command input, arranged to change the state of the reference circuit according to the value present at the command input, characterized by: a counter, externally accessible by a counter output interface, arranged to count a signal derived from said oscillator, while the reference circuit is in low-power state. ### Claim 2 (depends on 1) The reference oscillator according to claim 1, further comprising a logic element stopping the counter when the reference circuit exits low-power state. ### Claim 3 (depends on 1) The reference oscillator according to claim 1, operatively arranged to reset the counter when the reference circuit enters low-power state. ### Claim 4 (depends on 1) The reference oscillator of according to claim 1, further including a wakeup output arranged to generate a wakeup signal after a predefined value has been reached by said counter. ### Claim 5 (depends on 1) The reference oscillator according to claim 1, wherein the temperature compensation circuit is disabled in the low-power state. ### Claim 6 (depends on 1) Use of a reference oscillator according to claim 1 in a GNSS receiver, wherein the receiver has a idle mode, in which satellite tracking is not carried out and the reference circuit is put into low-power mode, the receiver being arranged to save a value of the time at which the receiver enters into idle mode, to retrieve the time elapsed in idle mode from the counter of the reference circuit, and to resume acquisition and tracking of satellites based on such knowledge of the time elapsed in idle state. ### Claim 7 (depends on 2) The reference oscillator according to claim 2, operatively arranged to reset the counter when the reference circuit enters low-power state. ### Claim 8 (depends on 2) The reference oscillator of according to claim 2, further including a wakeup output arranged to generate a wakeup signal after a predefined value has been reached by said counter. ### Claim 9 (depends on 3) The reference oscillator of according to claim 3, further including a wakeup output arranged to generate a wakeup signal after a predefined value has been reached by said counter. ### Claim 10 (depends on 2) The reference oscillator according to claim 2, wherein the temperature compensation circuit is disabled in the low-power state. ### Claim 11 (depends on 3) The reference oscillator according to claim 3, wherein the temperature compensation circuit is disabled in the low-power state. ### Claim 12 (depends on 4) The reference oscillator according to claim 4, wherein the temperature compensation circuit is disabled in the low-power state. ### Claim 13 (depends on 2) Use of a reference oscillator according to claim 2 in a GNSS receiver, wherein the receiver has a idle mode, in which satellite tracking is not carried out and the reference circuit is put into low-power mode, the receiver being arranged to save a value of the time at which the receiver enters into idle mode, to retrieve the time elapsed in idle mode from the counter of the reference circuit, and to resume acquisition and tracking of satellites based on such knowledge of the time elapsed in idle state. ### Claim 14 (depends on 3) Use of a reference oscillator according to claim 3 in a GNSS receiver, wherein the receiver has a idle mode, in which satellite tracking is not carried out and the reference circuit is put into low-power mode, the receiver being arranged to save a value of the time at which the receiver enters into idle mode, to retrieve the time elapsed in idle mode from the counter of the reference circuit, and to resume acquisition and tracking of satellites based on such knowledge of the time elapsed in idle state. ### Claim 15 (depends on 4) Use of a reference oscillator according to claim 4 in a GNSS receiver, wherein the receiver has a idle mode, in which satellite tracking is not carried out and the reference circuit is put into low-power mode, the receiver being arranged to save a value of the time at which the receiver enters into idle mode, to retrieve the time elapsed in idle mode from the counter of the reference circuit, and to resume acquisition and tracking of satellites based on such knowledge of the time elapsed in idle state. ### Claim 16 (depends on 5) Use of a reference oscillator according to claim 5 in a GNSS receiver, wherein the receiver has a idle mode, in which satellite tracking is not carried out and the reference circuit is put into low-power mode, the receiver being arranged to save a value of the time at which the receiver enters into idle mode, to retrieve the time elapsed in idle mode from the counter of the reference circuit, and to resume acquisition and tracking of satellites based on such knowledge of the time elapsed in idle state.