# US 2022/0037873 A1 · Methods, apparatus, and systems to facilitate a fault triggered diode emulation mode of a transistor

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- Number: US 2022/0037873 A1
- Document ID: US20220037873A1
- Status: Published application
- Kind: A1
- Application number: 17/505,757
- Filed: 2021-10-20
- Published: 2022-02-03
- Earliest claimed: 2019-03-27
- Assignees: Texas Instruments Incorporated
- Applicants: Texas Instruments Incorporated
- Inventors: Serkan Dusmez; Nathan Richard Schemm; Salil Chellappan
- Web page: https://patentgrep.com/patent/US20220037873A1

## CPC

- H02H 5/04: responsive to abnormal temperature {(specially adapted for electric machines H02H7/0852)}
- H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)}
- H02H 7/1213: {for DC-DC converters}
- H02M 1/32: Means for protecting converters other than automatic disconnection
- H03K 17/0822: {in field-effect transistor switches}
- H03K 17/18: Modifications for indicating state of switch
- H03K 17/302: {in field-effect transistor switches}
- H02M 3/158: including plural semiconductor devices as final control devices for a single load
- H02M 7/5387: in a bridge configuration
- Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
- H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H)
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- 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)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

Methods, systems, and apparatus to facilitate a fault triggered diode emulation mode of a transistor. An example apparatus includes a driver to output a control signal to a gate terminal of a transistor of a power converter; and a diode emulation control circuit to, in response to determining a fault corresponding to the transistor, enable the transistor when current flows in a direction from a source terminal of the transistor to a drain terminal of the transistor.

## Claims

### Claim 1

A circuit comprising:
a comparator having a first comparator input, a second comparator input, a power input, and a comparator output;
a switch having a first switch terminal, a second switch terminal, and a control terminal, the first switch terminal coupled to the power input and the second switch terminal coupled to a voltage supply terminal; and
a state machine coupled to the control terminal.

### Claim 2 (depends on 1)

The circuit of claim 1, further comprising a differential amplifier having a first amplifier input, a second amplifier input, and an amplifier output, the amplifier output coupled to the first comparator input.

### Claim 3 (depends on 2)

The circuit of claim 2, wherein the first amplifier input is coupled to a first current terminal of a transistor and the second amplifier input is coupled to a second current terminal of the transistor.

### Claim 4 (depends on 1)

The circuit of claim 1, wherein the first comparator input is coupled to a current sensor for a transistor.

### Claim 5 (depends on 1)

The circuit of claim 1, further comprising a driver coupled to the state machine.

### Claim 6 (depends on 1)

The circuit of claim 1, wherein the state machine is configured to in response to detecting a fault, send an enable signal to the control terminal.

### Claim 7 (depends on 1)

The circuit of claim 1, wherein the state machine is configured to instruct the switch to close in response to detecting a fault.

### Claim 8

A circuit comprising:
a transistor having a first current terminal, a second current terminal, and a control terminal;
a diode emulation circuit coupled to the control terminal;
a driver coupled to the control terminal and to the diode emulation circuit; and
a state machine coupled to the diode emulation circuit and to the driver.

### Claim 9 (depends on 8)

The circuit of claim 8, further comprising an inductor coupled to the second current terminal.

### Claim 10 (depends on 8)

The circuit of claim 8, wherein the diode emulation circuit is a first diode emulation circuit, the transistor is a first transistor, and the control terminal is a first terminal, the circuit further comprising:
a second transistor, having a third current terminal, a fourth current terminal, and a second control terminal, the third current terminal coupled to the second control terminal and the second control terminal coupled to the driver; and
a second diode emulation circuit coupled the second control terminal and to the state machine.

### Claim 11 (depends on 8)

The circuit of claim 8, wherein the diode emulation circuit is coupled to the first current terminal and to the second current terminal.

### Claim 12 (depends on 8)

The circuit of claim 8, further comprising a current sensor coupled to the diode emulation circuit, wherein the current sensor is configured to measure current of the transistor.

### Claim 13 (depends on 8)

The circuit of claim 8, further comprising a temperature sensor coupled to the state machine, wherein the temperature sensor is configured to measure a temperature of the transistor.

### Claim 14 (depends on 8)

The circuit of claim 8, wherein the transistor is a GaN transistor.

### Claim 15

A method of diode emulation, the method comprising:
in response to receiving an enable signal:
in response to current flowing through a transistor in a first direction, applying, by a diode emulation circuit, a first control signal to a gate of a switch to enable current to flow through the switch; and
in response to current flowing through the transistor in a second direction different than the first direction, applying, by the diode emulation circuit, a second control signal to the gate of the switch to prevent current from flowing through the switch.

### Claim 16 (depends on 15)

The method of claim 15, further comprising in response to receiving a disable signal, disabling the diode emulation circuit.

### Claim 17 (depends on 15)

The method of claim 15, wherein the enable signal indicates an over-temperature fault of the transistor.

### Claim 18 (depends on 15)

The method of claim 15, further comprising transmitting, by a driver, a third control signal to the gate of the switch in response to receiving, by the driver, instructions from a controller.

### Claim 19 (depends on 15)

The method of claim 15, further comprising in response to detecting a fault, producing, by a state machine, the enable signal.

### Claim 20 (depends on 15)

The method of claim 15, wherein the transistor is a GaN transistor.