# US 10,873,300 B2 · Semiconductor device, current detecting method, and load drive system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,300 B2 - Document ID: US10873300B2 - Status: Granted - Kind: B2 - Application number: 16/242,722 - Filed: 2019-01-08 - Published: 2019-08-01 - Granted: 2020-12-22 - Earliest claimed: 2018-01-30 - Assignees: Renesas Electronics Corporation - Applicants: Renesas Electronics Corporation - Inventors: Keisuke Kimura - Web page: https://patentgrep.com/patent/US10873300B2 ## CPC - H03F 1/3211: {in differential amplifiers} - G01R 19/0092: {Measuring current only} - G01R 19/10: Measuring sum, difference or ratio - G01R 31/40: Testing power supplies (testing photovoltaic devices H02S50/10) - H01F 7/064: {Circuit arrangements for actuating electromagnets (circuit arrangements for obtaining special operating characteristics H01F7/18; driving circuits for electromagnets making use of a switching regulator H01H47/325)} - H01F 7/1844: {Monitoring or fail-safe circuits (for relays H01H47/002)} - H03F 3/45475: {using IC blocks as the active amplifying circuit} - H03K 2217/0027: Measuring means of, e.g. currents through or voltages across the switch - H03F: AMPLIFIERS - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract A semiconductor device has a drive transistor coupled to a load and a current detection circuit. The current detection circuit includes: an operational amplifier amplifying a potential difference between voltage of a first terminal and voltage of a second terminal; a sense transistor passing sense current between the first terminal and the drive transistor; a voltage supply circuit having a first current source and supplying voltage higher than voltage supplied to the grounding voltage terminal to the second terminal; a third terminal outputting current based on the sense current; a second current source coupled between the third terminal and the grounding voltage terminal; and a current source control circuit controlling current of the first and second current sources. Detection current detected by the current detection circuit is current obtained by subtracting the current of the second current source from the current based on the sense current. ## Claims ### Claim 1 A semiconductor device comprising: a drive circuit driving a load; and a current detection circuit detecting current flowing in the drive circuit, wherein the drive circuit comprises: an external output terminal to which the load is coupled; a first voltage terminal to which first voltage is supplied; a first drive transistor which has a first electrode coupled to the external output terminal and a second electrode coupled to the first voltage terminal; and wherein the current detection circuit comprises: a power supply voltage terminal to which a power supply voltage is supplied; a differential amplifier amplifying a potential difference between voltage of a first terminal and voltage of a second terminal; a first sense transistor passing sense current between the first terminal and the first electrode of the first drive transistor; a voltage supply circuit supplying voltage higher than voltage supplied to the first voltage terminal to the second terminal; a third terminal outputting detection current; a first current source coupled to the third terminal; and a control circuit controlling supplying voltage of the voltage supply circuit and current of the first current source, and wherein the detection current detected by the current detection circuit is current obtained by subtracting the current of the first current source from current based on the sense current. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, the voltage supply circuit having, a second current source coupled between the power supply voltage terminal and the second terminal, and a fourth transistor coupled between the first voltage terminal and the second terminal, wherein when the current based on the current flowing in the load is smaller than a predetermined value, the current of the second current source is larger than the current of the first current source and, when the current based on the current flowing in the load is equal to or larger than the predetermined value, the current of the first current source is larger than the current of the second current source. ### Claim 3 (depends on 2) The semiconductor device according to claim 2, wherein the control circuit detects current flowing from the external output terminal toward the load, when the current based on the current flowing in the load is smaller than the predetermined value, the second current source passes current from the power supply voltage terminal to the second terminal and, when the current based on the current flowing from the external output terminal toward the load is equal to or larger than the predetermined value, the second current source does not pass current, and wherein when the current based on the current flowing from the external output terminal toward the load is smaller than the predetermined value, the first current source does not pass current and, when the current based on the current flowing from the external output terminal toward the load is equal to or larger than the predetermined value, the first current source passes current from the third terminal to the first voltage terminal. ### Claim 4 (depends on 2) The semiconductor device according to claim 2, wherein the control circuit controls so as to increase the current based on the current flowing from the external output terminal toward the load and decrease the current of the second current source when the current based on the current flowing from the external output terminal toward the load is smaller than a predetermined value, and controls so as not pass current to the second current source when the current based on the current flowing from the external output terminal toward the load is equal to or larger than the predetermined value, and wherein the current source control circuit controls so as not to pass current to the first current source when the current based on the current flowing from the external output terminal toward the load is smaller than the predetermined value and controls so as to increase the current based on the current flowing from the external output terminal toward the load and increase the current of the first current source when the current based on the current flowing from the external output terminal toward the load is equal to or larger than the predetermined value. ### Claim 5 (depends on 1) The semiconductor device according to claim 1, wherein the load is a solenoid having one end coupled to the external output terminal and having another end to which grounding voltage is supplied. ### Claim 6 (depends on 1) The semiconductor device according to claim 1, wherein current based on current flowing from the external output terminal toward the load is current flowing in the first drive transistor. ### Claim 7 (depends on 1) The semiconductor device according to claim 1, wherein current based on current flowing from the external output terminal toward the load is current flowing in the first sense transistor. ### Claim 8 (depends on 2) The semiconductor device according to claim 2, further comprising a fourth terminal to which first voltage is supplied, wherein the control circuit generates a first replica current and a second replica current as copies of current flowing in the first sense transistor, wherein the control circuit having a third current source, wherein the second current source is coupled between the power supply voltage terminal and the fourth terminal and generates current by subtracting the first replica current from the current of the third current source, and wherein the first current source is coupled between the third terminal and the fourth terminal and generates current by adding the second replica current to the current of the third current source. ### Claim 9 (depends on 1) The semiconductor device according to claim 1, wherein the current detection circuit further comprises a fourth current source coupled between the third terminal and the first voltage terminal and subtracts current of the fourth current source from the detection current. ### Claim 10 (depends on 1) The semiconductor device according to claim 1, further comprising a drive circuit control unit controlling the drive circuit on the basis of the detection current, wherein the drive circuit control unit has an analog/digital converter converting the detection current to a digital value. ### Claim 11 (depends on 10) The semiconductor device according to claim 10, wherein the control unit further comprises an addition circuit of subtracting a value corresponding to a voltage value supplied from the voltage supply circuit from the digital value. ### Claim 12 (depends on 1) The semiconductor device according to claim 1, the drive circuit comprises: an input voltage terminal to which input voltage is supplied, a second drive transistor which sets a conductive state or a non-conductive state between the external output terminal and the input voltage terminal, wherein the current detection circuit further comprises a switch transistor setting a conductive state or a non-conductive state between the first terminal and the first voltage terminal, and wherein when the second drive transistor is in a conductive state, the switch transistor is in a conductive state. ### Claim 13 (depends on 1) The semiconductor device according to claim 1, wherein the current detection circuit further comprises: a first transistor coupled so as to form a current path between the power supply voltage terminal and the first terminal; and a second transistor coupled so as to form a current path between the power supply voltage terminal and the third terminal, and wherein an output of the differential amplifier is coupled to the gate of the first transistor and the gate of the second transistor, and the first and second transistors configure a current mirror circuit. ### Claim 14 (depends on 1) The semiconductor device according to claim 1, wherein the current detection circuit further comprises a third transistor coupled so as to form a current path between the first terminal and the third terminal, and wherein an output of the first differential amplifier is coupled to the gate of the third transistor. ### Claim 15 (depends on 1) The semiconductor device according to claim 1, wherein the current detection circuit further comprises a second sense transistor passing sense current between the first terminal and the first voltage terminal, wherein the voltage supply circuit comprises: a first shift transistor setting a conductive state or a non-conductive state between the second terminal and the first voltage terminal; and a second shift transistor setting a conductive state or a non-conductive state between the second terminal and the first drive transistor, and wherein when the semiconductor device operates in a first mode, the first shift transistor enters the conductive state and, when the semiconductor device operates in a second mode, the second shift transistor enters the conductive state. ### Claim 16 (depends on 15) The semiconductor device according to claim 15, wherein in the first mode, one end of a solenoid is coupled to the external output terminal, and grounding voltage is supplied to the other end of the solenoid. ### Claim 17 (depends on 15) The semiconductor device according to claim 15, wherein in the second mode, one end of a solenoid is coupled to the external output terminal, and power supply voltage is supplied to the other end of the solenoid. ### Claim 18 (depends on 15) The semiconductor device according to claim 15, the drive circuit comprises: an input voltage terminal to which input voltage is supplied, a second drive transistor which sets a conductive state or a non-conductive state between the external output terminal and the input voltage terminal, wherein the current detection circuit further comprises a switch transistor for setting a conductive state or a non-conductive state between the first terminal and the first voltage terminal, and wherein when the second drive transistor is in the conductive state, the switch transistor is set to the conductive state. ### Claim 19 A current detecting method comprising the steps of: passing current to a first driver transistor having, a first electrode coupled to an external output terminal to which a load is coupled, and a second electrode coupled to a first voltage terminal to which first voltage is supplied; passing sense current to a first sense transistor coupled between a first terminal of a differential amplifier amplifying a potential difference between voltage of the first terminal and voltage of a second terminal and the first electrode of the first drive transistor; supplying voltage higher than the first voltage to the second terminal; passing current from a first current source coupled to a third terminal outputting detection current to the first voltage terminal; and detecting value of current flowing in the first drive transistor obtaining the detection current by subtracting current of the first current source from the current based on the sense current. ### Claim 20 A load drive system comprising: a load; a semiconductor device driving the load; and a semiconductor integrated circuit device controlling the semiconductor device, wherein the semiconductor device comprises: a drive circuit having an external output terminal to which the load is coupled, a first voltage terminal to which first voltage is supplied, an input voltage terminal to which input voltage is supplied, a first drive transistor having a first electrode coupled to the external output terminal and, a second electrode coupled to the first voltage terminal, and a second drive transistor coupled to the external output terminal and the input voltage terminal; and a current detection circuit having a power supply voltage terminal to which a power supply voltage is supplied, a differential amplifier amplifying a potential difference between voltage of a first terminal and voltage of a second terminal, a first sense transistor passing sense current between the first terminal and the first electrode of the first drive transistor, a voltage supply circuit supplying voltage to the second terminal higher than voltage supplied to the first voltage terminal, a third terminal outputting detection current, a first current source coupled between the third terminal and the first voltage terminal; and a control circuit controlling voltage of the voltage supply circuit and current of the first current source, and wherein the detection current detected by the current detection circuit is current obtained by subtracting the current of the first current source from the current based on the sense current.