US 10,746,837 B2Granted

Methods and devices for high stability precision voltage dividers

AssigneeGuildline Instruments Limited

InventorsRichard Timmons, Andre Perras, Mark Evans, Tomasz Barczyk

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Abstract

Resistor voltage dividers are commonly used to create reference voltages, or to reduce the magnitude of a voltage so it can be measured. Many measurements in test and measurement or calibration applications regularly require accuracies within the sub-part per million (ppm) range, e.g. 0.1 ppm to 1.0 ppm. However, the continued drive for improved accuracy in calibration, standards, and measurements on circuits and components means many measurements and measurement systems are operating at 50 parts per billion (ppb) and below to approximately 10 ppb. At these levels even relatively simple passive elements such as voltage dividers cannot be used without calibration and that these calibrations may be required at frequencies substantially higher than the other elements within the test and measurement equipment. Accordingly, the inventors have established a self-contained voltage divider with internal calibration allowing the voltage divider to be calibrated for every measurement if necessary.

Claims7

Dependent claims

A device comprising:

a resistive divider network comprising a plurality of stages disposed in series between an input and a ground;
each stage of the plurality of stages having an output port having a voltage equal to an applied voltage at an input port of the stage divided by a predetermined ratio established in dependence upon the resistances within that stage of the plurality of stages;
wherein each input port of a stage of the plurality of stages apart from the stage of the plurality of stages having its input port coupled to the input is coupled to an output port of a preceding stage of the plurality of stages;
wherein
the resistive divider network has either a first configuration or a second configuration;
in the first configuration:
each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground comprises three resistors in series of nominally the same resistance between its input port and its output port;
the stage of the plurality of stages having its output port coupled to the ground comprises a single resistor;
and
the output port of each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground is coupled to the ground by a resistor;
and
in the second configuration:
each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground comprises:
a resistive divider comprising:
a first resistor coupled at a first end to the input port;
a second resistor coupled at a first end to the output port;
a third resistor coupled at a first end to the other end of the first resistor and at its other end of the other end of the second resistor;
a first relay coupled between the first end of the first resistor to the other end of the third resistor;
and
a second relay coupled between the first end of the second resistor and the first end of the third resistor;
the stage of the plurality of stages having its output port coupled to the ground comprises a single resistor;
wherein
the first resistor, the second resistor and the third resistor are all of nominally the same resistance;
the first relay can be independently set into a first configuration such that the first resistor is part of the resistive divider and into a second configuration such that the first resistor is bypassed;
and
the second relay can be independently set into a first configuration such that the second resistor is part of the resistive divider and into a second configuration such that the second resistor is bypassed.

23 more elements

A device comprising:

a resistive divider network comprising a plurality of stages disposed in series between an input and a ground;
each stage of the plurality of stages having an output port having a voltage equal to an applied voltage at an input port of the stage divided by a predetermined ratio established in dependence upon the resistances within that stage of the plurality of stages;
wherein
each input port of a stage of the plurality of stages apart from the stage of the plurality of stages having its input port coupled to the input is coupled to an output port of a preceding stage of the plurality of stages;
wherein
the resistive divider network has either a first configuration or a second configuration;
in the first configuration the stage of the plurality of stages having its output port coupled to the ground comprises an adjustment circuit comprising:
a pair of first resistors of nominally a same first resistance disposed in series between the input port and the ground;
a pair of second resistors of nominally a same second resistance disposed in series between the input port and the ground;
and
a third resistor having a first end coupled to a midpoint between the pair of second resistors and its other end coupled to a first end of a first potentiometer and a second potentiometer;
wherein
a tunable port of the first potentiometer is coupled to the ground;
and
a tunable port of the second potentiometer which is variable is coupled to the ground;
and
in the second configuration the stage of the plurality of stages having its output port coupled to the ground comprises an adjustment circuit comprising:
a pair of first resistors of nominally a same first resistance disposed in series between the input port and the ground;
a pair of second resistors of nominally a same second resistance disposed in series between the input port and the ground;
and
a third resistor having a first end coupled to a midpoint between the pair of second resistors and its other end coupled to a first end of a first potentiometer;
wherein
a tunable port of the first potentiometer is coupled to the ground.

20 more elements

A device comprising:

a resistive divider network comprising a plurality of stages disposed in series between an input and a ground;
each stage of the plurality of stages having an output port having a voltage equal to an applied voltage at an input port of the stage divided by a predetermined ratio established in dependence upon the resistances within that stage of the plurality of stages;
wherein
each input port of a stage of the plurality of stages apart from the stage of the plurality of stages having its input port coupled to the input is coupled to an output port of a preceding stage of the plurality of stages;
wherein
the resistive divider network has either a first configuration or a second configuration;
in the first configuration:
the output port of each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground is also coupled to a predetermined port of a plurality of ports via a resistor;
and
the stage of the plurality of stages having its output port coupled to the ground comprises an adjustment circuit comprising:
a pair of first resistors of nominally a same first resistance disposed in series between the input port and the ground;
a pair of second resistors of nominally a same second resistance disposed in series between the input port and the ground;
and
a third resistor having a first end coupled to a midpoint between the pair of second resistors and its other end coupled to a first end of a first potentiometer;
wherein
a tunable port of the first potentiometer is coupled to the ground;
and
in the second configuration:
the output port of each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground is also coupled to a predetermined port of a plurality of ports via a resistor;
and
the stage of the plurality of stages having its output port coupled to the ground comprises an adjustment circuit comprising:
a pair of first resistors of nominally a same first resistance disposed in series between the input port and the ground;
and
a third resistor having a first end coupled to a midpoint between the pair of first resistors and its other end coupled to a first end of a first potentiometer;
wherein
a tunable port of the first potentiometer is coupled to the ground.

23 more elements

A device comprising:

a resistive divider network comprising a plurality of stages disposed in series between an input and a ground;
each stage of the plurality of stages having an output port having a voltage equal to an applied voltage at an input port of the stage divided by a predetermined ratio established in dependence upon the resistances within that stage of the plurality of stages;
wherein
each input port of a stage of the plurality of stages apart from the stage of the plurality of stages having its input port coupled to the input is coupled to an output port of a preceding stage of the plurality of stages;
wherein
the resistive divider network has either a first configuration or a second configuration;
in the first configuration:
the output port of each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground is coupled to the input port of the next stage of the plurality of stages via a resistor;
the output port of each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground is coupled to a potentiometer via a series resistor;
and
the output port of the penultimate stage of the plurality of stages having its output port coupled to the stage of the plurality of stages having its output port coupled to the ground is also coupled to the ground via an adjustment circuit;
and
the adjustment circuit comprises:
a resistor having a first end coupled to the output port of the penultimate stage of the plurality of stages and a second end coupled to a potentiometer;
wherein
a tunable port of the first potentiometer is coupled to the ground;
and
in the second configuration:
the output port of each stage of the plurality of stages apart from the stage of the plurality of stages having its output port coupled to the ground is coupled to a different first potentiometer;
the input port of the stage of the plurality of stages having its output port coupled to the ground is also coupled to the ground via a resistor having a first end coupled to the input port of the stage of the plurality of stages and a second end coupled to a second potentiometer where the tunable port of the second potentiometer is coupled to the ground;
a tunable port of each first potentiometer is coupled to the ground;
and
a tunable port of the second potentiometer is coupled to the ground.

20 more elements

A device comprising:

a resistive divider network comprising a plurality of stages disposed in series between an input and a ground;
each stage of the plurality of stages having an output port having a voltage equal to an applied voltage at an input port of the stage divided by a predetermined ratio established in dependence upon the resistances within that stage of the plurality of stages;
wherein each input port of a stage of the plurality of stages apart from the stage of the plurality of stages having its input port coupled to the input is coupled to an output port of a preceding stage of the plurality of stages;
wherein
the resistive divider network has either a first configuration or a second configuration;
in the first configuration:
the stage of the plurality of stages having its output port coupled to the ground comprises:
a first resistor having a first end coupled to the input port of the stage of the plurality of stages and its other end coupled to a first end of a second resistor;
the second resistor having its other end coupled to the ground;
a third resistor having a first end coupled to the input port of the stage of the plurality of stages and its other end coupled to a first end of a potentiometer;
and
the potentiometer wherein the other end of the potentiometer and a tunable port of the potentiometer are both coupled to the ground;
wherein
the second resistor and the third resistor are nominally the same resistance;
and
in the second configuration:
the stage of the plurality of stages having its output port coupled to the ground comprises:
a first resistor having a first end coupled to the input port of the stage of the plurality of stages and its other end coupled to a first end of a second resistor;
the second resistor having its other end coupled to the ground;
a third resistor having a first end coupled to the input port of the stage of the plurality of stages and its other end coupled to a first end of a fourth resistor and a first end of a potentiometer;
the fourth resistor having its other end coupled to the ground;
and
the potentiometer wherein a tunable port are both coupled to the ground.

20 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/426,900Filed 30 May 2019 · division
Priority: 22 Apr 2016
Published: US 2019/0293742 A126 Sep 2019
Granted: 18 Aug 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01R 35/007
Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references: standards or reference devices, e.g.…
G01R 15/04
Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00: voltage dividers
G01R 35/005
Testing or calibrating of apparatus covered by the other groups of this subclass: calibrating; Standards or reference devices, e.g. voltage or…
G01R
Measuring electric variables

Family

Application62/326,293Us provisional application · filed 22 Apr 2016
Application15/458,241Parent of this division · filed 14 Mar 2017
US 2019/0293742 A1Pre-grant publication · published 26 Sep 2019
US 10,353,045 B2Parent of this division
US 2017/0307718 A1Published application
US 10,746,837 B2This patent

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