TW201307805A - Control circuit, sensor array, and method for operating a control circuit - Google Patents

Abstract

The invention relates to a control circuit for controlling an actuator and/or a sensor, in particular a rotation rate sensor, wherein the control circuit comprises a sensor interface configured for transmitting a control signal to the sensor and a charge pump for increasing an electrical voltage of the control signal. Furthermore, the charge pump is directly connected with the sensor interface in an electrically conductive manner.

Description

Control circuit, sensor device, and method of operating control circuit

The invention relates to a control circuit for the citation of the first application of the patent scope.

Such a control circuit for controlling a rotational speed sensor is known to the prior art. For example, a rotational speed sensor is described in German Patent No. DE 10 2007 000 168 A1, which has a seismisch mass, the mass The vibration caused by the Coriolis force is excited by the driving means of the electric subtractive operation. When there is a rotational speed, the seismic measurement block generates a Kelvin force which deflects the seismic mass substantially perpendicular to the Kelvin force and perpendicular to the rotational speed. Here, the deflection is proportional to the rotational speed, so that the deflection amount is measured by a detecting means as a value to measure the rotational speed. In order to square the Kelvin force vibration. A constant current control voltage is typically applied, the voltage level of which is increased by a charge pump (Charge Pump) to a potential that exceeds the supply voltage. Here, the control voltage is generally generated by a digital analog converter of an ASIC (Application Specific Integratod Circuit) and is correspondingly amplified by an amplifier also on the ASIC. Here, the terminal of the supply voltage of the supply is connected to the charge pump to increase the potential in a corresponding manner. For example, the document US 6,300,820 B1 mentions such a charge pump. The increased control voltage is applied by the amplifier to the output terminal pad of the ASIC. The control signal input terminal pad (also referred to as the square frequency adjustment pad) of the original speed sensor is connected to the output pad of the ASIC via a "bonding wire", for example.

A disadvantage of this device is that the charge pump is regulated by an amplifier to make the current consumption of the amplifier high. This is necessary because, on the one hand, a large voltage range is required at the output of the amplifier, and on the other hand, at the output of the amplifier, the voltage range must be adjusted very accurately, in other words, it needs to have a high resolution ( Minor adjustment). In addition, in order to achieve such high resolution, the digital analog converter must be designed to have a higher resolution, and thus, the area and current requirements on the ASIC are large.

The control circuit of the present invention, as well as the sensor device of the present invention in accordance with another independent item, and the method of the present invention for operating a control circuit have an advantage over the prior art that the current demand is greatly reduced. This is achieved by connecting the charge pump directly to the sensor interface, rather than connecting to the sensor interface via an additional amplifier or using the amplifier to make, runrate. The control signal is applied directly to the charge pump rather than to an input of the additional amplifier (which is placed between the charge pump and the sensor interface), so the voltage regulation operation at the sensor interface is utilized on the charge pump The supply voltage and / or input voltage is achieved. Therefore, the prior art practice of using an additional amplifier can be completely eliminated. The facts show that this current demand is reduced many times. Because the output of the charge pump is not regulated by the amplifier as in the prior art. In particular, the charge pump is only in the required small voltage range of the control signal and requires less accuracy. Rather than the entire potential voltage range that is always required to have high accuracy in prior art waters is available. The control circuit should preferably be provided on a semiconductor substrate (especially germanium). Especially in an ASIC on. The ASIC preferably has a sensor interface in the form of a pad (contact surface) which preferably has an ESD (electrostatic discharge) configuration. The charge pump preferably includes a multi-stage charge pump, that is, a series of Kaskaden circuits of charge pump amplification stages. The control circuit of the present invention is particularly useful for controlling a speed sensor and is preferably used to square adjust a speed sensor, wherein the control signal is preferably applied to the sensor interface in the form of a DC control signal. However, it is also conceivable to use the control circuit of the present invention for controlling various actuators and/or sensors, in particular active (aktiv) sensors, the sensor and/or the actuator particularly comprising an integrated The sensor and/or the actuator [it is particularly suitable for integration into a semiconductor substrate (preferably helium) using surface micromechanical means].

Preferred designs and further features of the present invention are found in the dependent claims and the description of the drawings.

According to a preferred embodiment, the control circuit has a voltage regulation coupled directly to the charge pump in a conductive manner, wherein the charge pump is disposed between the voltage regulator and the sensor interface. The voltage regulator is specifically connected to the voltage supply of the charge pump, so the output voltage of the charge pump can advantageously be controlled by a "control signal", for example, the voltage regulator comprising a simple source tracker.

According to a preferred embodiment, the control circuit has a digital analog converter directly coupled to the charge pump in a conductive manner to convert a digital control signal into an analog control signal, wherein the charge pump is set in the digital analog conversion Between the device and the sensor interface. Thus, the output signal of the digital analog converter is advantageously utilized to control the supply voltage of at least one stage of the charge pump. This digital analog converter can be designed as compared to the prior art. Making space is much tighter. Because the resolution of the digital analog converter can be transmitted from the input to the output of the control circuit in a 1:1 ratio, instead of increasing the resolution by an amplifier between the input and the output by several times as in the prior art (so Even the deviation/error will increase by several times).

In accordance with a preferred embodiment, the charge pump includes a multi-stage charge pump, wherein a first stage of the multi-stage charge pump is coupled to the voltage regulator in a conductive manner and is preferably coupled to the digital analog converter. Conductive mode. It is therefore advantageous to increase the voltage level of the control signal to a multiple of the available supply voltage. Thus, for example, the speed sensor or other active sensor can be effectively controlled.

According to a preferred embodiment, the multi-segment charge pump comprises at least another phase which is connected in electrical conduction with at least one other voltage regulator. Thus the output voltage range of the further phase of the charge pump can advantageously be adjusted via the further voltage regulator, so that the control circuit can effectively match the requirements of the sensor and/or the actuator.

Another object of the invention is a sensor device having a control circuit and a sensor, wherein the charge pump is directly coupled to a control interface of the sensor via the sensor interface. The charge pump can therefore be connected directly to the sensor in an advantageous manner. The control voltage (whose voltage level has been used by the charge pump to increase the square frequency control especially for a speed sensor with a special power saving method. Therefore, the control interface includes a square or frequency adjustment pad with an ESD configuration. The resulting "loss current" is mainly based on the loss current in the ESD structure, which is smaller than the loss current generated in the prior art amplifier, which is mainly used only for the square or frequency adjustment pad. Table 1 shows the capacitance, so no obvious circuit occurs in the low frequency generally used.

Another object of the present invention is a method for operating a control circuit, wherein: a voltage of a control signal is boosted by a charge pump, and the control signal is directly guided by the charge pump to a sensor interface. The detector interface is configured to be connected to a sensor. Advantageously, therefore, no additional amplifier between the charge pump and the sensor interface is required, so current consumption is greatly reduced compared to the prior art. The sensor interface preferably includes a square and/or frequency adjustment pad of the sensor and/or actuator.

According to a preferred embodiment, the electrical control signal is coupled to the charge pump via a voltage regulator. Therefore, the output voltage of the charge pump can be adjusted directly via the control signal.

In accordance with a preferred embodiment, the control signal is converted from a digital control signal (4') to an analog control signal using a voltage regulator in the form of a digital analog converter. It is therefore preferred to use a digital control signal to control the method of operation of the present invention and to control the sensor and/or actuator.

According to a preferred embodiment, the voltage of the control signal is increased by a multi-stage charge pump, wherein the control signal is conducted to a first stage of the multi-stage charge pump via the voltage regulator, and wherein the multi-stage charge pump At least another phase should be adjusted via another voltage regulator. The output voltage of the charge pump can thus be advantageously adjusted with the additional charge regulator or digital analog converter.

The embodiments of the present invention are shown in the drawings and described in detail in the following description.

The same and identical parts in different figures are always represented by the same figure number, so they are generally only mentioned once or once.

1 is a schematic diagram of a sensor device (10) having a control circuit (1) in accordance with a first embodiment of the present invention. The sensor device has a control circuit (1) and a sensor (2) (for example designed to be in the form of a mechanical speed sensor, the control circuit (1) in an ASIC (1') (varies depending on the application) The integrated circuit is implemented on the substrate (2) in a separate substrate (2') [which is processed by a surface micromechanical mechanism], and the rotational speed sensor (1) comprises a seismic mass (13) (which is also often referred to as a Kelly force sensing element or sensor element). It is suspended to move relative to the substrate (2'). This seismic mass (13) is excited by a capacitive drive unit (14) In the case of a working vibration (15), in this case, the working vibration (15) is oriented parallel to a main extension plane (100) of the substrate (2'). To this end, the drive unit (14) is firmly fixed to A finger construction (14') of the upper member of the substrate, between which the opposite electrode (14") of the seismic mass (13) is designed to be in the form of a member electrode. Due to the finger electrode configuration (14) Electrostatic alternating between ') and the opposite electrode (14"). An alternating voltage [which is applied between the finger electrode structure (14') and the opposite electrode (14") on each side of the seismic mass (13)] a drive The force acts on the seismic mass (13). This causes the working vibration (15). If there is a rotational speed (16) at this time, for example, its orientation is perpendicular to the working vibration (15) and parallel to the main extension plane (10). ), a Kj of a vertical main extension plane (100) acts on the seismic mass (13), thus causing a one-kilogram deflection of the seismic mass (13) perpendicular to the main extension plane (100). (17) An amount of the rotational speed (16) to be measured by the K-wire deflection system, and capacitively measured by the planar electrode element (18), for example, the planar electrode element is disposed in the seismic mass (13) And substrate (2'). The square frequency adjustment of the speed sensor is achieved by a control circuit (1) via a control interface (9) of the sensor (2) (especially a square frequency adjustment pad), for example with a drive unit ( 14) Coupling, the control circuit (1) has a charge pump (5) connected directly to the control interface (9) via a sensor interface (3) in a conductive manner, thus the voltage across the sensor interface (3) The regulation is achieved directly using the charge pump (5). For example, the sensor interface (3) and the control interface (9) include contact pads and/or contact pins that are electrically connected to each other via "bonding wires" and/or via a circuit board for protection. In order to prevent static electricity from overvoltage, the gaskets should each have an ESD structure (not shown). A digital control signal (4) (4') is converted to an analog control signal (4) on the ASIC (1') using a voltage regulator (6) [which is designed in the form of a digital analog converter (6'). ") This type of ratio control signal (4) (4") is directly applied to a voltage supply terminal of the charge pump (5). The charge pump (5) is used to raise the voltage level beyond the supply voltage available on the ASIC (1'), thus in particular controlling an effective square compensation.

2 is a schematic view of a sensor device (10) having a control circuit (1) according to a second embodiment of the present invention, wherein the second embodiment is substantially identical to the first embodiment shown in FIG. The control circuit (1) is also used to control any actuator and/or sensor (2) that includes a related (sensor) interface (7) (particularly a spacer) and An active actuator or sensor element (12). Furthermore, the control circuit (1) has a charge pump (5), which in this case is designed in the form of a multi-stage charge pump, ie the charge pump (5) has a majority stage (7) (7') (7"). Most stages (7)(7')(7") are designed based on the voltage level requirement of the analog signal (4''') on the sensor interface (2). Figure 2 shows the charge pump (5) in a schematic manner using point (19). The three stages shown (7)(7')(7") are more stages. The digital control 仩(4') uses a digital, analog converter to convert to an analog signal (4"), which is applied to the charge pump The input of the first stage (7) of (5), in addition, the supply voltage (20) of the first stage (7) is correspondingly adjusted by means of another voltage regulator (8). Stage (7) is followed by the other phase (7) (7') (7") of the charge pump (5), where its supply voltage terminal (20) is also adjusted with other voltage regulators (8). The last additional The output of stage (7") is connected to the sensor interface (3) in a conductive manner, so that the amplified analog control signal (4''') is output to the sensor interface (3), thus, in the sensor interface The voltage regulation of (3) is achieved directly by the power supply and/or input voltage of the charge pump (5). If this is not the case, it is also conceivable to directly connect the analog control signal (4') to the supply voltage terminal (20) of the first stage (7).

(1)‧‧‧Control circuit

(1')‧‧‧ASIC (integrated circuit for application)

(2) ‧‧‧ sensors

(2') ‧‧‧Substrate

(3) ‧‧‧sensor interface

(4) ‧‧‧ control signals

(4')‧‧‧ Control signals

(4")‧‧‧Control signals

(4''') ‧‧‧ control signals

(5)‧‧‧Charge pump

(6)‧‧‧Voltage regulator

(6’)‧‧‧Digital Analog Converter

(7) ‧ ‧ stages

(7’) ‧ ‧ stage

(7") ‧ ‧ stage

(9) ‧‧‧Control interface

(10)‧‧‧Sensor device

(13) ‧‧‧ seismic mass

(14)‧‧‧Capacitive drive unit

(14’)‧‧‧ finger electrode construction

(14") ‧ ‧ opposite electrodes

(15) ‧‧‧Working vibration

(16)‧‧‧Speed

(17)‧‧‧Kelvin deflection

(18)‧‧‧ planar electrode components

(19) ‧ ‧ points

(20)‧‧‧Supply voltage terminals

(100)‧‧‧Main extension plane

1 is a schematic diagram of a sensor device having a control circuit according to a first embodiment of the present invention; FIG. 2 is a schematic diagram of a sensor device having a control circuit according to a second embodiment of the present invention;

(1)‧‧‧Control circuit

(1')‧‧‧ASIC (integrated circuit for application)

(2) ‧‧‧ sensors

(2') ‧‧‧Substrate

(3) ‧‧‧sensor interface

(4) ‧‧‧ control signals

(4')‧‧‧ Control signals

(4")‧‧‧Control signals

(4''') ‧‧‧ control signals

(5)‧‧‧Charge pump

(6)‧‧‧Voltage regulator

(6’)‧‧‧Digital Analog Converter

(9) ‧‧‧Control interface

(10)‧‧‧Sensor device

(13) ‧‧‧ seismic mass

(14)‧‧‧Capacitive drive unit

(14’)‧‧‧ finger electrode construction

(14") ‧ ‧ opposite electrodes

(15) ‧‧‧Working vibration

(16)‧‧‧Speed

(17)‧‧‧Kelvin deflection

(18)‧‧‧ planar electrode components

(100)‧‧‧Main extension plane

Claims (10)

A control circuit (1) for controlling an actuator and/or a sensor (2), in particular for controlling a speed sensor, wherein the control circuit (1) has a sensor interface (3) and a a charge pump (5) configured to send a control signal (4) to the sensor (2) for boosting the control signal (4) The voltage is characterized in that the charge pump (5) is directly connected to the sensor interface (3) in a conductive manner. For example, in the control circuit of claim 1, wherein: the control circuit (1) has a voltage regulation (6) directly connected to the charge pump (5) in a conductive manner, wherein the charge pump (5) is set at the voltage Between the regulator (6) and the sensor interface (3). A control circuit according to any one of the claims, characterized in that the control circuit (1) has a digital analog converter (6) directly connected to the charge pump (5) in a conductive manner to control a digital position. The signal (4') is converted to an analog control signal (4"), wherein the charge pump (5) is disposed between the digital analog converter (6') and the sensor interface (3). The control circuit of claim 2, wherein the charge pump (5) comprises a multi-stage charge pump (5'), wherein the first stage of the multi-stage charge pump (5') (7) The voltage regulator (6) is connected in a conductive manner, and is preferably connected to the digital analog converter (6') in a conductive manner. The control circuit of claim 4, wherein: the multi-stage charge pump (5') comprises at least another stage (7'), and the other stage (7') and at least another voltage regulator (8) Connected to a conductive way. A sensor device (10) having a patent application scope a control circuit (1) according to any one of items 1 to 5, and a sensor (2), characterized in that the charge pump (5) directly communicates with the sensor (2) via the sensor interface (3) A control interface (9) is connected. A method for operating a control circuit (1) according to any one of claims 1 to 5, characterized in that the voltage of a control signal (4) is increased by a charge pump (5), and the control The signal (4) is directed by the charge pump (5) to a sensor interface (3) that is configured for connection to a sensor (2). The method of claim 7, wherein the electrical control signal (4) is coupled to the charge pump (5) via a voltage regulator (6). The method of claim 7, wherein the control signal (4) is converted from a digital control signal (4') to an analogy using a voltage regulator (6) in the form of a digital analog converter (6'). Control signal (4'). The method of claim 7 or 8, wherein the voltage of the control signal (4) is increased by a multi-stage charge pump (5), wherein the control signal (4) is guided via the voltage regulator (6) Up to a first stage (7) of the multi-stage charge pump (5'), and wherein the multi-stage charge pump (5') is preferably at least another stage (7') regulated via another voltage regulator (6) .