CN111096065A - Temperature stabilizing device with accelerated response to power supply variations - Google Patents
Temperature stabilizing device with accelerated response to power supply variations Download PDFInfo
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L1/00—Stabilisation of generator output against variations of physical values, e.g. power supply
- H03L1/02—Stabilisation of generator output against variations of physical values, e.g. power supply against variations of temperature only
- H03L1/04—Constructional details for maintaining temperature constant
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/19—Control of temperature characterised by the use of electric means
- G05D23/1919—Control of temperature characterised by the use of electric means characterised by the type of controller
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/14—Modifications for compensating variations of physical values, e.g. of temperature
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B11/00—Automatic controllers
- G05B11/01—Automatic controllers electric
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L1/00—Stabilisation of generator output against variations of physical values, e.g. power supply
- H03L1/02—Stabilisation of generator output against variations of physical values, e.g. power supply against variations of temperature only
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/0019—Circuit arrangements
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Abstract
A temperature stabilizing device having improved response to changes in power supply voltage level includes a heater circuit for a heating device assembly and a temperature control circuit in which a heater control signal is adjusted with changes in power supply voltage level.
Description
Technical Field
The present invention relates to temperature-stabilized electronic devices in which the transient response of the device to changes in the power supply is accelerated in order to shorten the time period required to bring the temperature of the device back to the control set point, and thus reduce undesirable transient changes in key performance parameters of the device.
Background
Key performance parameters of many electronic devices often depend on ambient temperature. For example, the frequency of the signal generated by the electronic oscillator depends on several external parameters, such as ambient temperature, power supply voltage, mechanical acceleration, wherein frequency instability is particularly pronounced due to ambient temperature changes.
Several techniques have been developed to reduce the sensitivity of key performance parameters in electronic devices to changes in ambient temperature. One such technique is temperature stabilization of the device, in which temperature sensitive parts of the electronic device are placed in a temperature stable environment, thus reducing the effects of ambient temperature variations.
One example of a temperature-stable electronic device is a constant temperature electronic oscillator. In an Oven Controlled Oscillator (OCO), the temperature of the device is controlled and maintained at a predetermined level that is typically set several degrees above the maximum operating temperature of the device; as a result, the temperature variation of the oscillator is greatly reduced compared to the variation of the ambient temperature, thereby improving the output frequency stability. Examples of constant temperature oscillator devices are: an oven controlled crystal oscillator (OCXO) including an oscillator circuit having a crystal resonator, an oven controlled Micro Electro Mechanical System (MEMS) oscillator (OCMO) including an oscillator circuit having a MEMS resonator, an oven controlled Surface Acoustic Wave (SAW) oscillator (OCSO) including an oscillator circuit having a SAW resonator, and the like.
In order to maintain a stable device assembly temperature in a temperature stabilizing device, closed loop temperature control techniques are often deployed. The diagram in fig. 1 (prior art) provides an example of such a control loop. As shown, the temperature of the device assembly 1 is sensed by means of a temperature sensor 2, the sensed temperature value ("device assembly temperature") is compared with a desired temperature value ("setpoint"), the value of the temperature error is calculated as the difference between the setpoint value and the actual device assembly temperature value, and the temperature error is then processed by an error processing block 3, the output of which controls one or several heaters 4 in order to minimize the temperature error value, thus bringing the temperature of the device closer to the setpoint.
Any of several known control algorithms may be used in the error processing block. For example, a proportional control algorithm may be used; in this control method, the output of the error handling block (i.e. the heater control signal) is arranged to be proportional to the temperature error:
SHC＝KP*ΔT (1)
wherein SHCIs the value of the heater control signal, KPIs a proportional control coefficient (also referred to as a proportional gain) and Δ T is a temperature error value (i.e., the difference between a desired temperature "set point" value and a value of the actual temperature of the device assembly). Depending on the particular circuit implementation, the heater control signal may be a voltage signal VHCOr current signal IHCAny one of them.
From expression (1), it can be seen that the proportional control algorithm will produce a permanent non-zero temperature error, often referred to as an "offset". In effect, once the temperature error reaches a zero value (i.e., when the device assembly temperature equals the desired "set point" value), the value of the heater control signal, SHCAlso becomes zero, which in turn causes the device assembly temperature to gradually deviate from the desired "set point" temperature. Assume that proportional gain value K is correctly setPAnd the control loop is stable, a steady state will be achieved, where SHCAnd the Δ T value is stable and non-zero, i.e., there is a permanent temperature "drift". To eliminate or at least minimize undesirable "offsets," the proportional control method can be enhanced by adding constant terms to the control expression:
SHC＝KP*ΔT+CHC(2)
wherein C isHCIs an added constant heater control term.
From the expression (2), the constant control term CHCWill actually eliminate offset errors if set correctlyPoor, but its value will only be optimal for a specific single value of the ambient temperature.
To adapt the additional term to the entire ambient temperature operating range, the additional term may be generated as a time integral of the temperature error Δ T; this control algorithm is called Proportional Integral (PI) and operates according to the following expression:
wherein KPIn order to obtain a proportional gain, the gain is,
the delta T is the value of the temperature error,
KIin order to integrate the gain, the gain is,
Integral calculation in expression (3)
Substitution of constant term C in expression (2)HCAnd represents a term that is automatically adjusted depending on the temperature error value Δ T. Due to its integral nature, the integral calculation in a PI controller lags behind in time, i.e., it takes some time for the integral calculation to fully function.
In addition to the proportional and proportional integral, other known control algorithms may be used to control the temperature of the assembly in the temperature stabilizing device. One important point is that the heater control signal S in any of such algorithmsHCIs generated as a function of only one variable-temperature error:
SHC＝f(ΔT) (4)
one of the inferences of expression (4) is that the control algorithm does not directly take into account the change in the power supply level. This means that if the power supply voltage of the temperature stabilizing device changes, this change will cause the amount of power dissipated in the heater to change and cause the device assembly temperature and temperature error values to change. Deviations of temperature errors are processed by a temperature control loop and the resulting evolutionIt takes a considerable time to function. In the case of PI control, the final correction Δ T is changed, but only after a certain time period, which consists of both: (a) at the integrator
The time required to integrate the changed Δ T value, and (b) the time required for the device assembly to acquire the desired temperature; the time period (b) will depend on the amount of thermal mass exhibited by the temperature stabilizing device assembly.
Another corollary to the variation in power supply voltage levels is that the power dissipated in the circuits and components of the temperature stabilizing device other than the heater will also vary. Because this dissipated power also contributes to device assembly heating, changes in dissipated power will result in additional temperature errors. Again, the temperature control loop in the prior art temperature stabilization device will eventually "notice" this change, but only after a certain period of time due to the nature of the integral control algorithm and the thermal mass of the device.
It is an object of the present invention to provide a technique that allows the time period required to bring the temperature of a temperature stabilizing device back to a set point after a change in the power supply voltage to be reduced, and reduces the undesirable effects of temperature disturbances on key performance parameters of the temperature stabilizing device, or at least provides an alternative, if not improved, technique to mitigate transient effects caused by a change in the power supply voltage in the temperature stabilizing device. For example, in an constant temperature oscillator (OCO) device, use of the techniques of the present disclosure may shorten and reduce the magnitude of transient temperature disturbances experienced by the device due to power supply changes, which shortens and reduces the change in output frequency produced by the OCO device.
Disclosure of Invention
The term "comprising" as used in the specification and claims means "consisting at least in part of … …". When interpreting each statement in this specification and claims that includes the term "comprising," features other than the one or more features prefaced by the term can also be present. Related terms such as "include" and "includes" are to be interpreted in the same manner.
In a first aspect thereof, the present invention provides a temperature stabilising device which is powerable by a power supply voltage source, the device comprising: a heater circuit for heating the device assembly; and a temperature control circuit arranged to generate a heater control signal to control the amount of power dissipated in the heater circuit, and wherein the heater control signal is arranged to be dependent on the power supply voltage level and to be electronically adjusted as the power supply voltage level changes.
In at least some embodiments, the temperature control circuit is arranged to control the amount of power dissipated in the heater circuit to maintain the device assembly temperature within at most ± 5%, more preferably at most ± 1%, more preferably at most ± 0.01% of the intended operating environment temperature range of the device.
In at least some embodiments, the heater control signal is arranged to be electronically adjusted with a change in the power supply voltage level that does not exceed ± 10%, more preferably ± 5%, more preferably ± 1%.
In a second aspect of the invention, in the above temperature stabilizing device, the electronic circuit is arranged to attenuate the heater control signal before the signal is applied to the heater circuit or the heater driver circuit.
Thus, there are two main aspects of the present invention.
I. In the first aspect of the present invention, an additional circuit is arranged in the temperature stabilizing device to perform the following functions; (a) sensing a power supply voltage level, and (b) generating a heater control signal that depends not only on the temperature error value, but also on the sensed power supply voltage value. In other words, for the temperature stabilizing device of the present invention, the above expression (4) is replaced by the following expression:
SHC＝f(ΔT,VS) (5)
wherein SHCIs the value of the heater control signal and,
at is the value of the temperature error,
VSis the value of the supply voltage.
The advantage of generating the heater control signal as a function of both the temperature error and the power supply voltage is that if the power supply voltage changes, the heater power is adjusted accordingly by the control algorithm so as to maintain the amount of heater power as needed to maintain a stable device assembly temperature; furthermore, because the heater control signal adjustment is done electronically, it occurs immediately after the supply voltage change and is significantly faster than the period of time that would otherwise be required to bring the device temperature to the requisite set point through the temperature control loop. The heater control signal generated according to expression (5) may be referred to as "power supply compensation".
In a second aspect of the invention, a further additional circuit is introduced in order to further accelerate the transient response of the temperature stabilizing device to changes in the power supply.
In temperature-stabilized electronic devices, power is dissipated not only in the heater, but also in every other electronic circuit and electronic component of the device. For example, in an OCO device, power dissipation also occurs in voltage regulator circuits, oscillator circuits, output buffer circuits, and the like. This internal dissipated power causes additional heating of the device, i.e., heating of the device in addition to the heating provided by the heater. At high ambient temperatures, the temperature dependent heater power decreases and the internal dissipated power becomes comparable to or even exceeds it.
When the power supply voltage level changes, the heater power may be adjusted using the techniques described as the first aspect of the invention without any significant delay. However, internal dissipated power changes will also occur, and temperature errors caused by such changes will not be corrected as quickly, as they will need to be corrected by the temperature control loop, with delays associated with the thermal mass of the device and sometimes the nature of the control algorithm deployed.
To accelerate the response of the temperature stabilizing device to changes in internal dissipated power resulting from changes in the supply voltage, in an embodiment, additional circuitry is introduced to subtract out a small amount of the power supply complementA compensated heater control signal, wherein the amount subtracted corresponds to the amount of internal dissipated power. This is further elucidated with reference to fig. 2 and 3. In a steady state, the temperature stabilizing device assembly temperature is stable; its stability is achieved by heating the device assembly to compensate for heat lost to the surrounding environment. As described above and shown in FIG. 2, the temperature stabilizing device heats through dissipated power PH1And internal dissipation power PDThe process is carried out.
P∑＝PH1+PD(6)
Wherein P is∑In order to heat the total power of the temperature stabilizing device,
PH1is the power dissipated in the heater and,
PDpower is dissipated internally.
In the conventional temperature stabilizing device, PH1And PDBoth values are power supply voltage dependent, and in case of a change in the power supply voltage, PH1And PDBoth will change resulting in a temperature error that will be processed by and minimized by the temperature control loop after a certain period of time due to the thermal mass of the device.
In the temperature stabilizing device implemented in accordance with the first aspect of the present invention, the heater power P is changed in the case where the power supply voltage is changedH1Will be maintained by additional circuitry as described herein in section I: i.e. heater control signal SHCCompensated for by the power supply and will adjust in time to account for supply voltage changes, and the heater power will be maintained at the level required to maintain the desired device temperature. However, the other component of the total power of the heating temperature stabilizing device, the internal dissipation power PDWill also change after a change in the supply voltage, resulting in a temperature error that will be time-corrected by the temperature control loop. To further improve the response time to changes in the supply voltage, the heating arrangement is modified according to a second aspect of the invention and is shown in fig. 3.
In this arrangement, the heater control signal compensated for in the power supply is applied to the heatingA small amount of said signal is subtracted before the heater or heater driver circuit, wherein the amount subtracted corresponds to the internal dissipated power PDThe amount of (c). This appears to the heater control loop as if it is also controlling internal dissipated power, which allows the technique described in section I of the present invention to compensate for internal dissipated power for power supply changes instantaneously.
Assume-for the sake of simplifying the explanation of the concept-that the amount of subtraction of the heater control signal corresponds to the internal dissipated power PDThe total heating power in the device shown in fig. 3 is then represented by the following expression:
P∑＝(PH2-PD)+PD(7)
because the total amount of power required to maintain a stable temperature of the OCO is the same in the arrangement shown in fig. 2 and 3, the following expression holds:
PH1+PD＝(PH2-PD)+PD(8)
this means that
PH2＝PH1+PD(9)
Thus, in the arrangement of figure 3 and according to the second aspect of the invention, subtracting a small amount of the power supply compensated heater control signal before it is applied to the heater or heater driver circuit results in an increase in the heater power required by the control loop, and because the control loop requirements are generated using the techniques disclosed as the first aspect of the invention, the total heating power in the temperature stabilising device is compensated electronically for power supply changes and will react to such changes significantly faster than in conventional temperature stabilising devices.
A more detailed description of the second aspect of the invention as applied to an Oven Controlled Oscillator (OCO) device is presented below.
Many contemporary OCO devices include voltage regulator circuits in order to generate supply voltages characterized by higher stability than the unregulated externally supplied power supply voltage.
Total power P dissipated in OCO assembly∑Is dissipation in a heater of an OCOPower P ofH1With power P dissipated in all other circuits internal to the OCODThe combination of (A) and (B):
PΣ＝PH1+PD
internal dissipation power PDDecomposable to be powered by an internally regulated supply and drawing a regulated supply current IrAnd an unregulated supply current I drawn by and supplied from an unregulated supplyurThe power dissipated by the circuit. Current IrDoes not depend on the external supply voltage V, since it is drawn by circuitry that sinks an internal regulated supply, while the (usually significantly smaller) current IurDoes vary with supply voltage V because it is drawn by circuitry directly connected to an external unregulated supply-hence current I in the following expressionurShown as a function of V:
PD＝Ir*V+Iur(V)*V
similarly, can be based on heater current IHCAnd voltage to express heater power
PH1＝IHC*V
Wherein IHCAccording to a first aspect of the invention, generation is for example inversely proportional to the supply voltage V and can be described by the following expression:
IHC＝ΔT*TG*IH/V*CG
in the above expression, Δ T is the temperature error signal, TGTemperature sensor gain for error processing stage, IHV is the power supply compensated heater control signal generated according to part I of the invention, and CGIs the current gain of the heater driver circuit.
According to a second aspect of the invention, a small amount of the heater control signal is subtracted before it is applied to the heater driver circuit:
IHC2＝(ΔT*TG*IH/V-IC)*CG
the extra current ICMust be accounted for in the total power budgetFiltering, thereby regulating the current IrIncrease IcTo become Ir1：
Ir1＝Ir+IC
New heater power PH2Represented by the formula:
PH2＝IHC2*V＝(ΔT*TG*IH/V-IC)*CG*V＝ΔT*TG*IH*CG-IC*CG*V
and a new value P of non-heater power dissipated in the deviceD1Comprises the following steps:
PD1＝Ir1*V+Iur(V)*V＝(Ir+IC)*V+Iur(V)*V
new total power P∑Thus is PH2And PD1Sum of (2)
PΣ＝PH2+PD1＝ΔT*TG*IH*CG-IC*CG*V+(Ir+IC)*V+Iur(V)*V
PΣ＝PH2+PD1＝ΔT*TG*IH*CG+{-IC*CG+(Ir+IC)+Iur(V)}*V
PΣ＝PH2+PD1＝ΔT*TG*IH*CG+{-IC*(CG-1)+Ir+Iur(V)}*V
From the latter expression, if I is madecEqual to a certain value as shown below, the terms in brackets tend to zero and the total power P∑Largely independent of supply voltage and to a greater extent than the technique of the application part I alone. Thus, the assembly responds to changes in the supply voltage more quickly than when the thermal control loop is allowed to correct for the changes. I required for this techniqueCThe optimum values of (c) are:
for this technique to work optimally, the current IurStress ratio IrMuch smaller, as is typically the case in well-designed OCO devices. And, in order to keep the total power consumption as low as possible, the current gain C of the heater driving circuitGShould be large, for example greater than 30.
Drawings
The invention is further described with reference to the accompanying drawings, in which
Figure 1 shows a temperature control loop in a conventional (prior art) temperature stabilization device,
figure 2 shows a heating power supply in a temperature stabilizing device,
figure 3 shows a heating power supply in a temperature stabilizing device incorporating the second aspect of the present invention,
figure 4 shows an example of an embodiment of a temperature stabilizing device incorporating the first aspect of the present invention,
figure 5 shows an example of an implementation of a power supply sensing circuit,
figure 6 shows a graph of temperature control gradient plotted as a function of adjustable circuit resistor value,
figure 7 shows an example of a circuit implementation to generate a power supply dependent heater control signal,
figure 8 shows an embodiment of a temperature stabilizing device incorporating both the first and second aspects of the present invention,
figure 9 shows the manner in which the current subtraction function is implemented,
figure 10 shows an example of a heater driver and heater circuit,
figure 11 shows an example of a heater driver and heater circuit with an added heater control signal subtraction circuit,
figure 12 shows an embodiment of a current sink module,
fig. 13, 14, 15 and 16 illustrate the performance benefits obtainable by utilizing the techniques of the present invention.
Detailed Description
FIG. 4 shows an embodiment of a temperature stabilizing device incorporating the first aspect of the present invention. The device assembly temperature is sensed using temperature sensor 1 and compared to a desired device assembly temperature ("setpoint") to calculate a temperature error value, which is input to error processing block 2. This block generates the heater control signal according to a selected control algorithm as described earlier herein. In a conventional temperature stabilizing device the heater control signal will be connected to the heater driver circuit, whereas in the device of the present invention an additional circuit power supply compensation circuit 3 is introduced in order to generate a heater control signal which is adjusted for changes in the power supply voltage level and thus depends on the level of the power supply voltage. The latter VSUPPLYAnd is therefore a necessary second input to the power supply compensation block 3 as shown in figure 4. Thus, the resulting power supply compensated heater control signal at point 4 is a function of both the current value of the temperature error and the current value of the power supply voltage.
The power supply compensated heater control signal at point 4 is connected as an input to a heater driver circuit 5 which drives a heater 6 to control and maintain a stable temperature of the device assembly 7.
Because the heater control signal 4 is continuously adjusted for any change in the power supply level (which includes regular adjustments at very short intervals, e.g. every 30ms), such changes will be responded to by the temperature stabilizing device of the present invention significantly faster than in conventional temperature stabilizing devices.
One way of implementing the power supply compensation circuit is by implementing it as a multiplier circuit that produces a product of the signal at the output of the error processing block and a signal that decreases linearly with the power supply voltage. In other words, in one implementation, the output of the supply sensing circuit is multiplied by the heating demand signal, and the resulting signal is used to drive the heating device.
An implementation of a power supply sensing circuit is shown in fig. 5. The circuit includes bipolar transistors Qref, Q0 and Q1, NMOS transistors M0 and M1 (size ratio M), a current source Iref, and emitter resistors R0 and R1, where the current I is0And I1Running through these resistors. VREG、VUREGAnd VREFAre a regulated voltage, an unregulated voltage, and a reference voltage used by the circuit, while IOUT is a power supply sense signal generated by the circuit. The Qref, Q0, and Q1 are configured such that the reference voltage is replicated across the emitters of Q0 and Q1, substantially fixing the voltages at these points. As the unregulated supply voltage changes, the current I0 also changes. An increase in the unregulated supply voltage increases current I0, and a decrease in the unregulated supply voltage decreases current I0. A current mirror with current gain M (comprising M0 and M1) subtracts M times the I0 current from the current I1. The difference is an output current signal (IOUT) representing a power supply voltage dependent signal.
The heating power can be expressed as:
power Vvureg×Iout
In the case of this circuit, it is,
Vreg＝Vref×2
Iout＝I1-M×I0
the heating power can now be expressed as:
the lowest sensitivity of the heating power to supply voltage variations will be achieved when
Because of the fact that
The optimum value of M for a given value of R0 and R1 is:
thus, by modifying the resistor R0It is possible to minimize heater power supply sensitivity for any given supply voltage, as shown in fig. 6, where the temperature control gradient (in deg.c/V) is plotted as a function of resistor value, with the optimum resistor value being near where the curve crosses the horizontal axis (i.e., the sensitivity to power supply variation is near zero). Alternatively, the value of M may be altered to obtain the optimum power supply sensitivity for a given value of R0 and R1. In an embodiment of the present invention, the value of M and the R0/R1 ratio may be selected together.
An embodiment of a complete circuit implementation to generate power supply dependent heater control signals is shown in FIG. 7. This circuit includes the power supply sensing circuit shown in fig. 5, as well as additional circuitry to generate the product of the power supply sensing signal IOUT and the heater demand signal (used in conjunction with the heater reference signal) generated by the temperature error processing circuit as described earlier. The additional circuits are made up of NPN transistors Q2, Q3, Q10-Q17, resistors R6 and R7, and current sources I3 and I4. In this circuit, the heater reference and heater demand are fed to a differential pair Q2, Q3, with current set by sources I3, I4, and operating conditions set at R7, Q17, and Q18. The difference signals from Q2 and Q3 are then fed to Q11 and Q10, which split the current IOUT from the supply sense circuit depending on the difference signal. Q12 and Q13 act as current mirrors such that the difference in current in Q10 and Q11 feeds into subsequent current mirrors Q14 and Q15 to generate a final output current, thus generating a power supply compensated heater signal to be used as a heater control signal to control power dissipated in the heater of the device.
Figure 8 shows an embodiment of a temperature stabilising arrangement incorporating both the first and second aspects of the invention. In contrast to and in addition to the device structure shown in fig. 4, an additional circuit 8 "heater control signal subtraction" is introduced to subtract a small portion of the power supply compensated heater control signal. As explained earlier herein, this appears to the heater control loop as if it is also controlling internal dissipated power, which allows the power supply compensation technique of the first aspect of the invention to compensate for internal dissipated power for power supply changes on or near the fly.
One way to implement the current subtraction function is by adding a simple programmable source that draws a settable amount of current from the power supply compensated heater control signal, as shown in fig. 9.
An example of a heater driver and heater circuit implementation is shown in fig. 10; the heater control current Iheat is multiplied by a factor of 68 in a current mirror formed by two NMOS transistors having a size ratio of 68 to 1, and the larger transistor is used as a heater for the device assembly.
An example of adding a heater control signal (current) subtraction circuit to the circuit shown in FIG. 10 is shown in FIG. 11; the subtraction circuit is labeled "current sink module" where terminal Iref accepts a reference current used by the subtraction circuit, terminal isselect is a digital bus that carries a binary signal to select the correct amount of heater control signal (current) to subtract, and the subtracted current flows through terminal Ia into the circuit ground reference.
An example of an embodiment of a current sink module is shown in fig. 12. In this circuit, the reference current Iref is mirrored from transistor N1 to transistors N2, N3, and N4 in ratios of 1, 2, and 4 times. Switches S1, S2, and S3 are controlled by the signal of the isselect bus to draw a binary weighted reference current of 0 to 7 times via terminal Ia.
Fig. 13 through 16 illustrate the performance benefits that can be obtained by utilizing the techniques of the present invention. Fig. 13 and 14 show the measured transient response of a conventional OCXO to changes in the power supply voltage. FIG. 13 shows transient output frequency changes after a 5% power supply voltage ramp up; as shown, the frequency destabilizes due to supply voltage changes, with transient disturbances settling for more than 30 seconds and producing a 12ppb p-p frequency deviation during the transient response. The 5% power supply voltage drop also results in transient output frequency changes of similar magnitude and duration as shown in fig. 14.
An OCXO device including an embodiment of the present invention exhibits a significantly accelerated response to step changes in the power supply voltage. As shown in fig. 15, the transient output frequency response to the rise in power supply voltage in the OCXO of the present invention occurs for less than 1 second and is not accompanied by any significant frequency deviation compared to the deviation in the conventional OCXO. The OCXO device of the present invention exhibits a similarly short transient response to a 5% power supply voltage drop without any significant frequency deviation, as shown in fig. 16.
Claims (14)
1. A temperature stabilising device capable of being powered by a power supply voltage source, the device comprising a heater circuit for a heating device assembly, and a temperature control circuit arranged to generate a heater control signal to control the amount of power dissipated in the heater circuit, and wherein the heater control signal is arranged to depend on a power supply voltage level and to electronically adjust with changes in the power supply voltage level.
2. The temperature stabilizing device of claim 1, wherein electronic circuitry is arranged to attenuate the heater control signal before the signal is applied to the heater circuit or heater driver circuit.
3. The temperature stabilization device of any one of claim 1 or claim 2, wherein the temperature stabilization device is a constant temperature oscillator device.
4. The constant temperature oscillator device of claim 3, wherein the constant temperature oscillator device is an constant temperature crystal oscillator device.
5. The constant temperature oscillator device according to claim 3, wherein the constant temperature oscillator device is a constant temperature SAW oscillator device.
6. The constant temperature oscillator device of claim 3, wherein the constant temperature oscillator device is a constant temperature MEMS oscillator device.
7. The temperature stabilization device of any one of claims 1 to 6, wherein the temperature control circuit is arranged to control the amount of power dissipated in the heater circuit to maintain the device assembly temperature within at most ± 5% of an intended operating environment temperature range of the device.
8. The temperature stabilization device of any one of claims 1 to 6, wherein the temperature control circuit is arranged to control the amount of power dissipated in the heater circuit to maintain the device assembly temperature within at most ± 1% of an intended operating environment temperature range of the device.
9. The temperature stabilization device of any one of claims 1 to 6, wherein the temperature control circuit is arranged to control the amount of power dissipated in the heater circuit to maintain the device assembly temperature within at most ± 0.01% of an intended operating environment temperature range of the device.
10. A temperature stabilising arrangement according to any one of claims 1 to 9, wherein the heater control signal is arranged to be adjusted electronically with changes in the power supply voltage level that do not exceed ± 10%.
11. A temperature stabilising arrangement according to any one of claims 1 to 9, wherein the heater control signal is arranged to be adjusted electronically with changes in the power supply voltage level that do not exceed ± 5%.
12. A temperature stabilising arrangement according to any one of claims 1 to 9, wherein the heater control signal is arranged to be adjusted electronically with changes in the power supply voltage level that do not exceed ± 1%.
13. A thermostatic oscillator device capable of being powered by a power supply voltage source, the device comprising an oscillator circuit, a heater circuit for heating a device assembly, and a temperature control circuit arranged to generate a heater control signal to control the amount of power dissipated in the heater circuit so as to maintain a stable device assembly temperature, and wherein the heater control signal is arranged to depend on and adjust with changes in the power supply voltage level.
14. A constant temperature oscillator device according to claim 13, wherein additional circuitry is arranged to attenuate the heater drive signal before the signal is applied to the heater circuit.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NZ735368 | 2017-09-08 | ||
| NZ73536817 | 2017-09-08 | ||
| PCT/IB2018/056821 WO2019049071A1 (en) | 2017-09-08 | 2018-09-07 | A temperature stabilized device with accelerated response to power supply variations |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111096065A true CN111096065A (en) | 2020-05-01 |
| CN111096065B CN111096065B (en) | 2022-11-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201880057585.7A Active CN111096065B (en) | 2017-09-08 | 2018-09-07 | Temperature stabilizing device with accelerated response to power supply variations |
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| Country | Link |
|---|---|
| JP (2) | JP7322004B2 (en) |
| CN (1) | CN111096065B (en) |
| WO (1) | WO2019049071A1 (en) |
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| GB1311476A (en) * | 1969-04-15 | 1973-03-28 | Radiation Ltd | Control arrangement for a cooker oven heating system |
| CN1819721A (en) * | 2005-01-14 | 2006-08-16 | 白光株式会社 | Control system for battery powered heating device |
| CN201113979Y (en) * | 2007-09-26 | 2008-09-10 | 东莞市金振电子有限公司 | High-frequency high precision locking phase constant temperature crystal oscillator |
| CN202404464U (en) * | 2011-11-25 | 2012-08-29 | 常州信息职业技术学院 | Temperature measuring and controlling device |
| EP2595315A1 (en) * | 2011-11-17 | 2013-05-22 | Imec | Ovenized system containing micro-electromechanical resonator |
| CN106664060A (en) * | 2014-06-25 | 2017-05-10 | 日本电波工业株式会社 | Oscillation device |
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| US6166608A (en) * | 1998-10-21 | 2000-12-26 | Symmetricom, Inc. | Thermo-electric cooled oven controlled crystal oscillator |
| JP6274919B2 (en) * | 2014-03-11 | 2018-02-07 | 日本電波工業株式会社 | Temperature control circuit of crystal oscillator with thermostatic chamber |
| JP5800171B1 (en) * | 2014-11-21 | 2015-10-28 | インターチップ株式会社 | Thermostatic bath crystal oscillator |
| JP6756173B2 (en) * | 2016-01-06 | 2020-09-16 | セイコーエプソン株式会社 | Circuits, oscillators, electronics and mobiles |
-
2018
- 2018-09-07 CN CN201880057585.7A patent/CN111096065B/en active Active
- 2018-09-07 WO PCT/IB2018/056821 patent/WO2019049071A1/en active Application Filing
- 2018-09-07 JP JP2020513543A patent/JP7322004B2/en active Active
-
2023
- 2023-06-20 JP JP2023100527A patent/JP2023126806A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1311476A (en) * | 1969-04-15 | 1973-03-28 | Radiation Ltd | Control arrangement for a cooker oven heating system |
| CN1819721A (en) * | 2005-01-14 | 2006-08-16 | 白光株式会社 | Control system for battery powered heating device |
| CN201113979Y (en) * | 2007-09-26 | 2008-09-10 | 东莞市金振电子有限公司 | High-frequency high precision locking phase constant temperature crystal oscillator |
| EP2595315A1 (en) * | 2011-11-17 | 2013-05-22 | Imec | Ovenized system containing micro-electromechanical resonator |
| CN202404464U (en) * | 2011-11-25 | 2012-08-29 | 常州信息职业技术学院 | Temperature measuring and controlling device |
| CN106664060A (en) * | 2014-06-25 | 2017-05-10 | 日本电波工业株式会社 | Oscillation device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2020533850A (en) | 2020-11-19 |
| JP7322004B2 (en) | 2023-08-07 |
| CN111096065B (en) | 2022-11-29 |
| JP2023126806A (en) | 2023-09-12 |
| WO2019049071A1 (en) | 2019-03-14 |
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