Current sensor
First Claim
1. A current sensor comprising:
- a Hall element;
a differential amplifier to amplify an output voltage of the Hall element, thus producing a sensor output voltage; and
a compensation circuit to compensate for variation in offset voltage of the current sensor, the compensation circuit having a plurality of series-connected diodes each exhibiting specific temperature characteristics based on a gradient of an approximated straight line given by a relationship between a residual Hall voltage of the Hall element at a given temperature and a rate of change in the residual Hall voltage due to temperature change, thus producing a compensation voltage in accordance with the temperature characteristics, the compensation voltage being added to the output voltage of the Hall element and input to the differential amplifier,wherein the series-connected diodes are divided into to a first diode group and a second diode group, the diode groups being connected in series in a forward bias direction via a resistor and having a specific same number of diodes connected in series in the forward bias direction, a resistor circuit being connected in parallel to the diode groups, the compensation voltage being output from the resistor circuit.
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Accused Products
Abstract
A current sensor has a Hall element, a differential amplifier that amplifying an output voltage of the Hall element, thus producing a sensor output voltage, and a compensation circuit that compensates for variation in offset voltage of the current sensor. The compensation circuit has a plurality of series-connected diodes each exhibiting specific temperature characteristics based on a gradient of an approximated straight line given by a relationship between a residual Hall voltage of the Hall element at a given temperature and a rate of change in the residual Hall voltage due to temperature change, to produce a compensation voltage in accordance with the temperature characteristics. The compensation voltage is added to the output voltage of the Hall element and input to the differential amplifier.
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Citations
4 Claims
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1. A current sensor comprising:
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a Hall element; a differential amplifier to amplify an output voltage of the Hall element, thus producing a sensor output voltage; and a compensation circuit to compensate for variation in offset voltage of the current sensor, the compensation circuit having a plurality of series-connected diodes each exhibiting specific temperature characteristics based on a gradient of an approximated straight line given by a relationship between a residual Hall voltage of the Hall element at a given temperature and a rate of change in the residual Hall voltage due to temperature change, thus producing a compensation voltage in accordance with the temperature characteristics, the compensation voltage being added to the output voltage of the Hall element and input to the differential amplifier, wherein the series-connected diodes are divided into to a first diode group and a second diode group, the diode groups being connected in series in a forward bias direction via a resistor and having a specific same number of diodes connected in series in the forward bias direction, a resistor circuit being connected in parallel to the diode groups, the compensation voltage being output from the resistor circuit. - View Dependent Claims (2, 3, 4)
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Specification