CN204681322U - The amplifier circuit that a kind of adjustable gain is whole and there is the Hall element of this circuit - Google Patents

Abstract

The utility model discloses the whole amplifier circuit of a kind of adjustable gain and there is the Hall element of this circuit, this amplifier circuit comprises the first amplifier, second amplifier, first proportion resistor, second proportion resistor, switch resistance array, wherein, described switch resistance array is connected between the inverting input of the first amplifier and the inverting input of the second amplifier, and, the first proportion resistor has been arranged in series between the output of described first amplifier and described switch resistance array, the second proportion resistor has been arranged in series between the output of described second amplifier and described switch resistance array, thus realize the two-way adjustment function of gain, adjust more convenient, and by trimming the gain of amplifier, adjustment Hall sensor chip, can for specific sensitivity requirement to the sensitivity in magnetic field, and the precision of its obtained Hall element is higher.

Description

The amplifier circuit that a kind of adjustable gain is whole and there is the Hall element of this circuit

Technical field

The utility model relates to a kind of amplifier circuit, the amplifier circuit that particularly a kind of adjustable gain is whole and have the Hall element of this circuit.

Background technology

In prior art, in order to ensure certainty of measurement, the gain being generally used for the discharge circuit that sensor signal is amplified all is designed to fixing multiple.The Hall magnetic field sensor chip of switching mode is in the impact of the process of producing due to the factor such as process drift, encapsulation stress, and the magnetic field sensitivity of finished product has fluctuation.Therefore, the finished product of transducer, generally by test, is classified according to the level of sensitivity in magnetic field, is formed different product hierarchies and be sold to client.Exceed in sensitivity or lower than the chip outside determined scope, will scrap as waste product, this will reduce the yield of product, and cannot produce in batches for the client of particular sensitivity demand.

Utility model content

The utility model is for solving the problem, provide the whole amplifier circuit of a kind of adjustable gain and have the Hall element of this circuit, Gain tuning is more convenient, and possesses two-way adjustment function, can for specific sensitivity requirement, the precision of its obtained Hall element is higher.

For achieving the above object, the technical solution adopted in the utility model is:

The amplifier circuit that a kind of adjustable gain is whole, it is characterized in that, comprise the first amplifier, the second amplifier, the first proportion resistor, the second proportion resistor, switch resistance array, wherein, described switch resistance array is connected between the inverting input of the first amplifier and the inverting input of the second amplifier, and, be arranged in series the first proportion resistor between the output of described first amplifier and described switch resistance array, between the output of described second amplifier and described switch resistance array, be arranged in series the second proportion resistor.

Preferably, described switch resistance array arranges formation primarily of multiple gain adjusting unit array, and each gain adjusting unit comprises the switch and Gain tuning resistance that are arranged in series further.

Preferably, described switch resistance array is preset with three modules: stuck-module, forward adjusting module, oppositely adjusting module, and modules is arranged by multiple gain adjusting unit array respectively and forms.

In addition, present invention also offers a kind of Hall element, it is characterized in that, it comprises the whole amplifier circuit of described adjustable gain.

The beneficial effects of the utility model are:

(1), described amplifier circuit comprises the first amplifier, the second amplifier, the first proportion resistor, the second proportion resistor, switch resistance array, thus realize carrying out two-way adjustment to the gain of hall sensing voltage amplifier circuit in Hall sensor chip, the magnetic field sensitivity of chip finished product is trimmed, improve product yield, the magnetic sensitivity Parameter adjustable of product is whole to desired value, effectively for target customer;

(2), between switch resistance array and amplifier Set scale resistance, the first proportion resistor, the second proportion resistor and switch resistance array strictly mate, and make the stability of amplifier circuit better;

(3), described switch resistance array is preset with three modules: stuck-module, forward adjusting module, oppositely adjusting module, make adjustment gain more convenient more directly perceived;

(4), each gain adjusting unit comprises the switch and Gain tuning resistance that are arranged in series further, by controlling the switch of each gain adjusting unit, and optionally disconnects or each switch of conducting, thus conveniently regulates.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide further understanding of the present utility model, forms a part of the present utility model, and schematic description and description of the present utility model, for explaining the utility model, is not formed improper restriction of the present utility model.In the accompanying drawings:

Fig. 1 is the block schematic illustration of the whole amplifier circuit of the utility model adjustable gain;

Fig. 2 is the electrical block diagram of the whole amplifier circuit of the adjustable gain of the utility model one preferred embodiment.

Embodiment

In order to make technical problem to be solved in the utility model, technical scheme and beneficial effect clearly, understand, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the utility model, and be not used in restriction the utility model.

As depicted in figs. 1 and 2, the amplifier circuit that a kind of adjustable gain of the present utility model is whole, it is characterized in that, comprise the first amplifier 10, second amplifier 20, first proportion resistor 11, second proportion resistor 21, switch resistance array 30, wherein, described switch resistance array 30 is connected between the inverting input of the first amplifier 10 and the inverting input of the second amplifier 20, and, the first proportion resistor 11 has been arranged in series between the output of described first amplifier 10 and described switch resistance array 30, the second proportion resistor 21 has been arranged in series between the output of described second amplifier 20 and described switch resistance array 30.

Described switch resistance array 30 arranges formation primarily of multiple gain adjusting unit array, and each gain adjusting unit comprises the K switch 1-K15 and Gain tuning resistance R1-R15 that are arranged in series further; In the present embodiment, described switch resistance array 30 is preset with three modules: stuck-module K1-K5 and R1-R5, forward adjusting module K11-K15 and R11-R15, oppositely adjusting module K6-K10 and R6-R10, and modules is arranged by multiple gain adjusting unit array respectively and forms.

As shown in Figure 2, the operation principle of amplifier circuit of the present utility model is as follows:

Switch resistance array 30 described in setting is made up of 15 switches of K1-K15 and 15 resistance of R1-R15, total equivalent resistance of this switch resistance array 30 is Ry, proportion resistor is Rx, generally, the resistance of the first proportion resistor 11 and the second proportion resistor 21 is equal, then, the computing formula of the gain A v of this amplifier is:

$\mathrm{Av}=\frac{\mathrm{OUT}1-\mathrm{OUT}2}{\mathrm{IN}1-\mathrm{IN}2}=\frac{2\mathrm{Rx}}{\mathrm{Ry}}+1;$

In following examples, K1-K15 is switching signal, and H represents high level, and represent switch conduction, L represents low level, represents that switch disconnects; Be R and the electric resistance array mated completely sized by R1-R15 is equal.

When chip initial designs, default K11-K15 is the switching signal of forward adjusting module, and K6-K10 is the switching signal of reverse adjusting module, and K1-K5 is the switching signal of stuck-module.Default K1-K10 is conducting state, and K11-K15 is off state, and now total equivalent resistance of the switch resistance array of R1-R15 composition is R/10; Suppose the negative feedback resistor Rx=10R of amplifier, then now the gain of this amplifier approximates 100 multiples.

If the chip finished product produced not in the scope estimated, then carries out following adjustment to the sensitivity in magnetic field:

1. the forward adjustment of amplifier gain

According to measurement of magnetic field value, determine that sensitivity needs the amplitude of adjustment, select Closing Switch K11-K15,

When the value listing K11-K15 with following table 1 is for various combination, the scope of this amplifier gain adjustment:

Table 1

K11	K12	K13	K14	K15	AV
						L	L	L	L	L	100
L	L	L	L	H	110
						L	L	L	H	H	120
L	L	H	H	H	130
						L	H	H	H	H	140
H	H	H	H	H	150

2. the reverse adjustment of amplifier gain

According to measurement of magnetic field value, determine that sensitivity needs the amplitude of adjustment, select cut-off switch K6-K10.

When the value listing K6-K10 with following table 2 is for various combination, the scope of this amplifier gain adjustment:

Table 2

K6	K7	K8	K9	K10	AV
						H	H	H	H	H	100
H	H	H	H	L	90
						H	H	H	L	L	80
H	H	L	L	L	70
						H	L	L	L	L	60
L	L	L	L	L	50

Above adjustment with initial value ± resize ratio of 50% for example, reality can carry out expanding or reducing according to practical condition.Further, the switching signal of K1-K15 produces by the modes such as resistance carries out fuse opening, laser blows, programming is blown of integrated chip inside.

It should be noted that, amplifier circuit of the present utility model trim scope, be not merely the adjusting range enumerated in above-mentioned specific embodiment, circuit diagram of the present utility model can also be utilized to carry out reducing step-length and segment, the sensitivity of adjustment product is to exact value; Or widen step-length, the magnetic field sensitivity scope of finished product is trimmed and says receptible scope to client, reduce testing procedure.

In addition, present invention also offers the Hall element of the whole amplifier circuit of a kind of adjustable gain comprising said structure, Hall element is divided into line style Hall element and Hall switch sensor two kinds, and the utility model is mainly applicable to Hall switch sensor.

The hall sensing voltage V of the Hall disc under certain magnetic field and current condition _h:

$V_H=\frac{G*r_H}{n*q*d}*I_{\mathrm{bias}}*B;$

Wherein:

G is the geometrical form factors of Hall disc HP;

R _hfor the dispersion factor of semiconductor carriers;

N is the doping content of Hall disc;

Q is elementary charge 1.602 × 10-19C;

D is the thickness of Hall disc;

I _biasfor the bias current by Hall disc HP;

B is outside applying magnetic field intensity.

This hall sensing voltage V in integrated sensor _hgeneral very faint, generally several millivolts of ranks, therefore this voltage can not directly apply to output driver, needs could apply after the amplification of certain multiple.

In the integrated hall sensors chip of reality, the hall sensing voltage produced by Hall disc is generally amplified by amplifier.And Hall magnetic field sensor chip is in the impact of the process of producing due to the factor such as process drift, encapsulation stress, the magnetic field sensitivity of finished product has fluctuation.Therefore the utility model is by trimming the gain of Hall voltage amplifier, and adjustment chip is to the sensitivity in magnetic field.

Above-mentioned explanation illustrate and describes preferred embodiment of the present utility model, as previously mentioned, be to be understood that the utility model is not limited to the form disclosed by this paper, should not regard the eliminating to other embodiments as, and can be used for other combinations various, amendment and environment, and can in utility model contemplated scope described herein, changed by the technology of above-mentioned instruction or association area or knowledge.And the change that those skilled in the art carry out and change do not depart from spirit and scope of the present utility model, then all should in the protection range of the utility model claims.

Claims (4)

1. the amplifier circuit that an adjustable gain is whole, it is characterized in that, comprise the first amplifier, the second amplifier, the first proportion resistor, the second proportion resistor, switch resistance array, wherein, described switch resistance array is connected between the inverting input of the first amplifier and the inverting input of the second amplifier, and, be arranged in series the first proportion resistor between the output of described first amplifier and described switch resistance array, between the output of described second amplifier and described switch resistance array, be arranged in series the second proportion resistor.

2. the amplifier circuit that a kind of adjustable gain according to claim 1 is whole, it is characterized in that: described switch resistance array is arranged by multiple gain adjusting unit array and forms, and each gain adjusting unit comprises the switch and Gain tuning resistance that are arranged in series further.

3. the amplifier circuit that a kind of adjustable gain according to claim 1 and 2 is whole, it is characterized in that: described switch resistance array is preset with three modules: stuck-module, forward adjusting module, oppositely adjusting module, and modules is arranged by multiple gain adjusting unit array respectively and forms.

4. a Hall element, is characterized in that, it comprises claim 1 or the whole amplifier circuit of the adjustable gain described in 2 or 3.