CN2909335Y - CPU real-time load current detection circuit - Google Patents

Abstract

The utility model relates to a real-time load current detection circuit of central processing unit includes a power supply circuit for provide the power to this central processing unit. The technology of the utility model is mainly characterized in that the utility model further comprises: a delay circuit, mainly having a resistor and a capacitor, connected to the power supply circuit; a current sensing circuit, which mainly comprises a comparison circuit connected with the delay circuit and the power supply circuit; a current feedback circuit, which mainly has a feedback current source and a resistor, connected to the current sensing circuit, wherein the feedback current source is used to mirror the sensing current. By means of the structure, the current can be accurately monitored, and errors are avoided.

Description

CPU real-time load current detection circuit

technical field

The utility model relates to the detection technology of load current, in particular to a real-time load current detection circuit of a central processing unit.

Background technique

In the Patent No. 200534069 "Current Load Detection Device and Power Supply System with Current Load Detection Device", a technology for detecting load current is disclosed. The known load detection circuit 60 is disclosed in its technical background. As shown in FIG. 2 , technically, the power supply 61 is mainly used to provide low-voltage direct current to supply the central processing unit 69 or other load devices during operation. required electricity. The high gate control signal and the low gate control signal are controlled by the energy storage inductance L6 and the energy storage capacitor C6 in cooperation with the PWM controller 62 to respectively control the open/close states of the two switches 64, so that the power supply 61 can Provides power to the CPU 69 . And then monitor the surface temperature of the central processing unit 69 by a resistor 66 and an inductor 67, which mainly detects the voltage drop on the resistor 66 by the inductor 67 to indirectly obtain the current amount of the central processing unit 69 or pressure drop changes.

The aforementioned technology uses the resistor 66 to measure the current change, and the error is large, and the corresponding measures (such as the speed control of the cooling fan of the CPU) cannot meet the requirements accurately.

And the aforementioned announcement No. 200534069 "current load detection device and power supply system with current load detection device" invention patent, its technology is mainly to improve the aforementioned defects, and add a current load detection to the aforementioned known circuit 60 The circuit 70 is shown in FIG. 3 . In this way, the high gate control signal and the low gate control signal, or the change of the high/low level maintenance time of the PWM signal can be detected, and corresponding measures can be taken in the first time (such as the cooling fan of the central processing unit The speed control is faster and the heat dissipation efficiency is better), which solves the aforementioned shortcomings.

Although the aforementioned technology can monitor the current, the detected current is comprehensively judged by the high gate control signal, the low gate control signal and the PWM signal to determine the change of the current. It still has errors.

Utility model content

The main purpose of the utility model is to provide a real-time load current detection circuit for a central processing unit, which monitors the current without errors.

In order to achieve the aforementioned purpose, a real-time load current detection circuit for a central processing unit provided by the present invention includes: a power supply circuit for providing power to the central processing unit. The technical focus of the present invention is to further include: a delay circuit, mainly having a resistor and a capacitor, connected to the power supply circuit; a current sensing circuit, mainly having a comparison circuit, the comparison circuit is connected to the delay The circuit and the power supply circuit; a current feedback circuit mainly has a feedback current source and a resistor connected to the current sensing circuit, and the feedback current source is used to mirror the sensing current.

The real-time load current detection circuit of the central processing unit, wherein: the resistance and the capacitance of the delay circuit are connected in series.

The real-time load current detection circuit of the central processing unit, wherein: the feedback current source of the current feedback circuit is connected in series with the resistor.

The real-time load current detection circuit of the CPU, wherein: the comparison circuit includes an operational (OP) amplifier.

The utility model can accurately monitor the load current of the central processing unit in real time by virtue of the above-mentioned structure, and there is less error.

Description of drawings

Fig. 1 is a circuit structure diagram of a preferred embodiment of the utility model;

Fig. 2 is a schematic diagram of a known load detection device;

FIG. 3 is a schematic diagram of a known current load detection device.

Detailed ways

In order to describe the structure and characteristics of the present utility model in detail, the following preferred embodiment is given and described as follows in conjunction with the accompanying drawings, wherein:

Fig. 1 is a circuit structure diagram of a preferred embodiment of the utility model.

As shown in Figure 1, a kind of CPU real-time load current detection circuit 10 provided by the first preferred embodiment of the utility model mainly consists of a power supply circuit 11, a delay circuit 21, a current sensing circuit 31 and A current feedback circuit 41 is formed, wherein:

The power supply circuit 11 is used to provide power to the CPU (not shown). The power supply circuit 11 mainly includes a power driver 12, two switches 14, a series equivalent resistance (DCR) of an inductor L, and a capacitor C1, the structure of which is connected is generally the same as that disclosed in the second example of the aforementioned known technology, I won't go into details.

The utility model is characterized in that:

The delay circuit 21 mainly has a resistor R _ISEN and a capacitor C _T connected in series and connected to the power supply circuit 11 .

The current sensing circuit 31 mainly has a comparison circuit 32 mainly composed of an operational (OP) amplifier 34 , the comparison circuit 32 is connected to the delay circuit 21 and the power supply circuit 11 .

The current feedback circuit 41 mainly has a feedback current source 42 and a resistor R1 connected in series to the current sensing circuit 31 , and the feedback current source 42 is used to mirror the sensing current I _SEN .

When the aforementioned circuit 10 is in operation, it mainly provides power through the power driver 12 first, and provides power to the central processing unit (not shown) through the effects of the switch 14, the inductance L, and the capacitor C1. The power supply mode is the same as the known technology, so it will not be repeated here.

The delay circuit 21 is used to make the currents of the two input terminals of the comparison circuit 32 consistent, so that the current sensing circuit 31 can use the ratio between the resistance DCR and the resistance R _ISEN of the delay circuit 21 and the current I _L on the inductor L to obtain the sensing current I _SEN , the calculation formula is shown in formula (1):

$I_{\mathrm{SEN}}=\frac{\mathrm{DCR}}{R_{\mathrm{ISEN}}}\&Center\; Dot;I_L$ -----------------------Formula 1)

The current feedback circuit 41 uses the feedback current source 42 to obtain an equivalent current in a similar current mirror manner by connecting the output terminal of the operational amplifier 34, and the feedback current source 42 is connected to the feedback circuit through the resistor R1. Current sensing of current source 42 . With this technology, the resistor R1 will not affect the current of the power supply circuit 11, and will not affect the sensing current I _SEN measured by the formula (1), without affecting the two currents The correct current value is measured under the conditions. Further, the effect of monitoring the current without errors is achieved.

The components disclosed in the embodiments of the utility model are for illustration purposes only, and are not intended to limit the patent scope of the utility model. The replacement and modification of other equivalent components should also be within the protection scope of the claims of the utility model. Covered, the actual scope of the utility model should still be subject to the protection scope of the claims.

Claims (4)

1. A central processing unit real-time load current detection circuit, comprising: A power supply circuit for providing power to the central processing unit; It is characterized in that it further includes: a delay circuit, mainly comprising a resistor and a capacitor, connected to the power supply circuit; A current sensing circuit mainly has a comparison circuit connected to the delay circuit and the power supply circuit; and A current feedback circuit mainly has a feedback current source and a resistor connected to the current sensing circuit, and the feedback current source is used to mirror the sensing current. 2. The CPU real-time load current detection circuit according to claim 1, wherein the resistance and capacitance of the delay circuit are connected in series. 3. The CPU real-time load current detection circuit according to claim 1, wherein the feedback current source of the current feedback circuit is connected in series with the resistor. 4. The CPU real-time load current detection circuit according to claim 1, wherein the comparison circuit comprises an operational amplifier.