Temperature compensating circuit and temperature compensating method for switch-type Hall sensor

Abstract

The invention discloses a temperature compensating circuit and a temperature compensating method for a switch-type Hall sensor. The temperature compensating circuit comprises a Hall chip, a differential amplifier, a switched capacitor circuit, a voltage stabilizer and a hysteresis comparator, wherein a reference current generating circuit and a threshold voltage generating circuit are connected in series between the voltage stabilizer and the switched capacitor circuit, and are used for generating reference current and threshold voltage to be provided to the hysteresis comparator; and the hysteresis comparator is used for comparing an amplified Hall induced voltage with a threshold voltage value, and outputting a discrimination result to an output stage. According to the temperature compensating circuit and the temperature compensating method, the reference current generating circuit module is added, the threshold voltage generating way is changed, the temperature compensating accuracy is higher, the influence of nonlinearity of a resistance temperature coefficient is eliminated, undifferentiated high-accuracy compensation can be realized on each temperature value, the requirement on a used process line is lowered, a resistor of a specific positive-negative temperature coefficient is not needed, and the selection range of the process line is expanded for a design engineer.

Description

technical field [0001] The invention relates to a temperature compensation circuit, in particular to a temperature compensation circuit of a switch-type Hall sensor; the invention also relates to a temperature compensation method of a switch-type Hall sensor. Background technique [0002] The Hall sensor is a magnetic field sensor made according to the Hall effect. The Hall effect is a kind of magnetoelectric effect, which was discovered by the American scientist Hall in 1879 when he was studying the conductive mechanism of metals. Later, it was found that the Hall effect of semiconductors is much stronger than that of metals. This phenomenon is used to make various Hall elements, which are widely used in industrial automation, automotive electronics, consumer electronics and other fields. [0003] Pass a bias current I across both ends of the semiconductor sheet, and apply a magnetic field with a magnetic induction intensity B in the vertical direction of the sheet, then a...

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Problems solved by technology

However, in practice, due to the non-linearity of the temperature coefficient of resistance, the compensation error of this scheme is relatively high, and it is impossible to achieve indiscriminate compensation at every temperature value.

In the production process of integrated circuits, affected by the precision of process control, the resistance value of different batches will have certain differences. Since the traditional compensation circuit uses two kinds of resistors with positive and negative temperature coefficients, the compensation effect is directly related to the resistance value. relationship, so traditional schemes are susceptible to process

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