Semiconductor device
A semiconductor device having: a semiconductor device unit including an output element and a sensing element; and a control circuit. When the output element is in an on state, the control circuit connects a high potential terminal of a sensing element to a high potential terminal of an output element and ungrounds a low potential terminal of the sensing element to cause the sensing element to function as a current sensing element for detecting a current flowing in the output element. When the output element is in an off state, the control circuit disconnects the high potential terminals of the sensing element and the output element, causes a constant current to flow through the high potential terminal of the sensing element, and grounds the low potential terminal of the sensing element to cause the sensing element to function as a temperature sensing element for detecting the temperature of the output element.
1. A semiconductor device for driving a load, comprising:
a semiconductor device unit, including
an output element that performs switching to operate the load, the output element having a high potential terminal, and
a sensing element having a high potential terminal and a low potential terminal; and
a control circuit coupled to the semiconductor device unit, the control circuit being configured to be operable,
when the output element is in an on state, to turn on the sensing element by connecting the high potential terminal of the sensing element to the high potential terminal of the output element and ungrounding the low potential terminal of the sensing element, to thereby cause the sensing element to function as a current sensing element for detecting a current flowing in the output element, and
when the output element is in an off state, to cut off a connection between the high potential terminal of the sensing element and the high potential terminal of the output element, to supply a constant current from the high potential terminal of the sensing element in a state where the low potential terminal of the sensing element is grounded, to thereby turn on the sensing element and cause the sensing element to function as a temperature sensing element for detecting a temperature of the output element.
2. The semiconductor device according to claim 1 , wherein
the control circuit includes:
a logic circuit,
a constant current source having an output end,
a first switch that connects or disconnects the output end of the constant current source and the high potential terminal of the sensing element, and
a second switch that grounds or ungrounds the low potential terminal of the sensing element;
the semiconductor device further includes a third switch that connects or disconnects the high potential terminal of the sensing element and the high potential terminal of the output element and that is disposed inside or outside the semiconductor device unit; and
the logic circuit is configured to generate and output, based on a level of a driving control signal for switching the output element and a level of a temperature detection control signal,
a first switching control signal for performing switching control of the first switch,
a second switching control signal for performing switching control of the second switch, and
a third switching control signal for performing switching control of the third switch.
3. The semiconductor device according to claim 2 , wherein the logic circuit is configured to be operable, responsive to the driving control signal being at a level that turns on the output element and the temperature detection control signal being at a level that causes the sensing element to function as the current sensing element,
to turn off the first switch with the first switching control signal, to thereby disconnect the output end of the constant current source from the high potential terminal of the sensing element,
to turn off the second switch with the second switching control signal, to thereby unground the low potential terminal of the sensing element, and
to turn on the third switch with the third switching control signal, to thereby connect the high potential terminal of the sensing element to the high potential terminal of the output element, and cause the sensing element to function as the current sensing element.
4. The semiconductor device according to claim 2 , wherein the logic circuit is configured to be operable, responsive to the driving control signal being at a level that turns off the output element and the temperature detection control signal being at a level that causes the sensing element to function as the temperature sensing element,
to turn on the first switch with the first switching control signal, to thereby connect the output end of the constant current source to the high potential terminal of the sensing element,
to turn on the second switch with the second switching control signal, to thereby ground the low potential terminal of the sensing element, and
to turn off the third switch with the third switching control signal, to thereby disconnect the high potential terminal of the sensing element from the high potential terminal of the output element, and cause the sensing element to function as the temperature sensing element.
5. The semiconductor device according to claim 2 , wherein the logic circuit includes:
an RS-type flip-flop having a set terminal, a reset terminal, an output terminal, and an inverting output terminal, and
a D-type flip-flop having a clock terminal, an input terminal, and an inverting output terminal, wherein
the RS-type flip-flop:
receives the driving control signal at the set terminal thereof,
receives the temperature detection control signal at the reset terminal thereof,
outputs the third switching control signal from the output terminal thereof, and
outputs the first switching control signal and the second switching control signal from the inverting output terminal thereof; and
the D-type flip-flop:
receives the driving control signal at the clock terminal thereof,
receives the temperature detection control signal at the input terminal thereof, and
outputs the sensing element driving control signal for driving the sensing element from the inverting output terminal thereof.
6. The semiconductor device according to claim 1 , wherein the control circuit includes:
a current detection resistor, which outputs the sensing current outputted from the current sensing element as a sensing current detection signal that is a voltage, and
a current detection circuit, which detects a current state of the output element by comparing the sensing current detection signal with a current detection reference voltage.
7. The semiconductor device according to claim 1 , wherein the control circuit includes a temperature detection circuit that detects a temperature state of the output element by comparing a sensing voltage detection signal, which is outputted from the temperature sensing element and falls due to a temperature characteristic of the sensing element when the constant current flows, with a temperature detection reference voltage.