US-12620984-B2 - Semiconductor device

US12620984B2US 12620984 B2US12620984 B2US 12620984B2US-12620984-B2

Abstract

A semiconductor device includes a switching element performing a switching base on an input signal to operate a load, a detection circuit outputting a release signal upon detecting a predetermined state of the switching element, and a driving current control circuit including a latch circuit that latches a detection result obtained from a magnitude of a current flowing through the switching element and to be reset upon receiving the release signal from the detection circuit. The control circuit outputs, based on an output of the latch circuit a first driving current or a second driving current larger than the first driving current. The driving current is used for charging a gate capacitance of the switching element in an operation state of the semiconductor device. The control circuit sets the driving current to the first driving current upon the latch circuit being reset by the release signal.

Inventors

Yuki KUMAZAWA

Assignees

FUJI ELECTRIC CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20240126
Priority Date: 20230317

Claims (9)

1 . A semiconductor device, comprising: a switching element configured to perform a switching on a basis of an input signal to operate a load; a detection circuit configured to output a release signal upon detecting a predetermined state of the switching element; and a driving current control circuit including a latch circuit configured to latch a data signal that depends on a magnitude of a current flowing through the switching element and to output a latched data signal in accordance with the input signal, wherein the driving current control circuit is configured to output, on a basis of an output of the latch circuit, a driving current for charging a gate capacitance of the switching element in an operation state of the semiconductor device, wherein the latch circuit is configured to receive the release signal from the detection circuit and to reset the output thereof upon receiving the release signal from the detection circuit, and wherein the driving current control circuit sets the driving current such that: (i) upon detecting that a current flowing through the switching element is less than a switching current value, the driving current control circuit sets the driving current to a first driving current; (ii) upon detecting that the current flowing through the switching element is greater than the switching current value, the driving current control circuit sets the driving current to a second driving current that is larger than the first driving current; and (iii) upon the latch circuit receiving the release signal, the driving current control circuit sets the driving current to the first driving current.
2 . The semiconductor device according to claim 1 , wherein: the predetermined state is at least one of an overcurrent state of the switching element in which an overcurrent flows through the switching element, an overheat state of the switching element in which the switching element is overheated, or a device power source voltage drop state in which a power voltage of the semiconductor device is lower than a predetermined level; and the detection circuit, upon detecting the predetermined state, outputs the release signal to the latch circuit, the release signal being also output to an outside of the semiconductor device to inform the predetermined state being detected, and being used to stop driving of the switching element.
3 . The semiconductor device according to claim 1 , wherein: the predetermined state is an overcurrent state of the switching element in which an overcurrent flows through the switching element; and the detection circuit, upon detecting the overcurrent state, outputs the release signal to the latch circuit, the release signal being also used to stop driving of the switching element.
4 . The semiconductor device according to claim 1 , wherein: the predetermined state is an overcurrent state of the switching element in which a current flowing through the switching element is equal to or greater than a predetermined current; and the detection circuit, upon detecting the overcurrent state, outputs the release signal to the latch circuit.
5 . The semiconductor device according to claim 1 , wherein: the predetermined state is a state in which the current flowing through the switching element is equal to or greater than a predetermined current and in which a driving voltage input to the switching element is equal to or greater than a predetermined voltage; and the detection circuit, upon detecting the predetermined state, outputs the release signal to the latch circuit.
6 . The semiconductor device according to claim 1 , wherein the driving current control circuit further includes a switching current detection circuit configured to detect whether or not the current flowing through the switching element is greater than the switching current value, and output a first switching signal in response to detecting that the current is less than the switching current value and a second switching signal in response to detecting that the current is greater than the switching current value, the latch circuit latching the detection result obtained from the first or second switching signal; a selection circuit configured to output, on a basis of the output from the latch circuit, a selection signal for setting the driving current to either the first driving current or the second driving current; and a driving current output circuit configured to output the first driving current or the second driving current on a basis of the selection signal.
7 . The semiconductor device according to claim 6 , wherein: the latch circuit, on a basis of the input signal, latches the detection result obtained from the first or second switching signal to output the detection result as the output of the latch circuit, or outputs a latch release output signal as the output of the latch circuit upon receiving the release signal, the selection circuit outputs a first selection signal upon receiving the output of the latch circuit obtained from the first switching signal or upon receiving the latch release output signal, and outputs a second selecting signal upon receiving the output of the latch circuit obtained from the second switching signal, and to charge the gate capacitance of the switching element, the driving current output circuit outputs the first driving current upon receiving the first selection signal or the latch release output signal and outputs the second driving current upon receiving the second selection signal.
8 . The semiconductor device according to claim 6 , wherein the switching element is included in one of upper arm and lower arm, and a boundary value between a first current region, when the first current region includes a maximum value of a voltage change rate of a switching element of the other one of the upper arm and lower arm when a diode of the other arm performs a recovery operation when the switching element of the one arm is turned on, of the current flowing through the switching element of the one arm and a second current region, when the second current region does not include the maximum value, and of the current flowing through the switching element of the one arm is set as the switching current value.
9 . A semiconductor device, comprising: a switching element configured to perform a switching on a basis of an input signal to operate a load; a state detection circuit configured to output a release signal upon detecting a predetermined state of the switching element; and a driving current control circuit including a switching current detection circuit configured to detect whether or not a current flowing through the switching element is greater than a switching current value, and a latch circuit configured to latch a data signal that depends on a magnitude of the current flowing through the switching element and to output a latched data signal in accordance with the input signal, wherein the driving current control circuit is configured to output, on a basis of an output of the latch circuit, a driving current for charging a gate capacitance of the switching element in an operation state of the semiconductor device, wherein the latch circuit is configured to receive the release signal from the state detection circuit and to reset the output thereof upon receiving the release signal from the state detection circuit, and wherein the driving current control circuit sets the driving current such that: (i) upon the switching current detection circuit detecting that the current flowing through the switching element is less than a switching current value, the driving current control circuit sets the driving current to a first driving current; (ii) upon the switching current detection circuit detecting that the current flowing through the switching element is greater than the switching current value, the driving current control circuit sets the driving current to a second driving current that is larger than the first driving current; and (iii) upon the latch circuit receiving the release signal output from the state detection circuit, the driving current control circuit sets the driving current to the first driving current.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2023-042470, filed on Mar. 17, 2023, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The embodiment discussed herein relates to a semiconductor device. 2. Background of the Related Art Semiconductor devices, such as intelligent power modules (IPMs), include power conversion switching elements such as insulated gate bipolar transistors (IGBTs). Furthermore, in recent years, an IPM having the function of controlling the magnitude of a driving current for charging an IGBT according to a collector current flowing through the IGBT has been developed. For example, a technique for adjusting driving capability by detecting a current flowing between the two main electrodes of a semiconductor switching element at timing at which the semiconductor switching element is turned off was proposed as a related art (see, for example, International Publication Pamphlet No. WO 2020/255640). Furthermore, a technique for using a plurality of comparators which compare an output voltage of a temperature detection means for detecting an operating temperature of a power semiconductor switching element with different reference voltages, for latching comparison results of the plurality of comparators, and for selectively outputting a comparison result was proposed (see, for example, Japanese Laid-open Patent Publication No. 2019-110677). In addition, a technique for using a state distinction circuit which latches current and temperature states and for releasing a latch by a reset signal was proposed (see, for example, Japanese Laid-open Patent Publication No. 2019-193410). SUMMARY OF THE INVENTION According to an aspect, there is provided a semiconductor device, including: a switching element configured to perform a switching on a basis of an input signal to operate a load; a detection circuit configured to output a release signal upon detecting a predetermined state of the switching element; and a driving current control circuit including a latch circuit configured to latch a detection result obtained from a magnitude of a current flowing through the switching element and to be reset upon receiving the release signal from the detection circuit, and being configured to output, on a basis of an output of the latch circuit, a driving current including a first driving current or a second driving current larger than the first driving current, the driving current being used for charging a gate capacitance of the switching element in an operation state of the semiconductor device, wherein the driving current control circuit sets the driving current to the first driving current upon the latch circuit being reset by the release signal. The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for describing an example of a semiconductor device; FIG. 2 illustrates an example of the structure of a semiconductor device that does not have a latch release condition; FIG. 3 is a time chart for describing the operation of a driving current control function; FIG. 4 illustrates an example of a short-circuit waveform of an IGBT; FIG. 5 illustrates an example of a short-circuit waveform of the IGBT; FIG. 6 illustrates an example of a short-circuit waveform of the IGBT; FIG. 7 illustrates an example of a short-circuit waveform of the IGBT; FIG. 8 illustrates an example of the structure of a semiconductor device; FIG. 9 illustrates an example of the structure of a filter circuit; FIG. 10 illustrates an example of the structure of a latch circuit; FIG. 11 illustrates an example of the structure of a selection circuit; FIG. 12 is a time chart illustrative of an example of the operation of the semiconductor device; FIG. 13 is a view for describing a switching current value; FIG. 14 illustrates a modification of the semiconductor device; FIG. 15 illustrates a modification of the semiconductor device; FIG. 16 illustrates a modification of the semiconductor device; FIGS. 17A and 17B are schematic views of a switching waveform of an IGBT, FIG. 17A being a schematic view illustrative of a waveform of a normal switching operation, FIG. 17B being a schematic view illustrative of a waveform of a short-circuit operation; and FIG. 18 illustrates an example of the structure of a power converter. DETAILED DESCRIPTION OF THE INVENTION An embodiment will now be described with reference to the accompanying drawings. Components in the specification and the drawings having substantially the same function are marked with the same numeral