# US 12,222,377 B2 · Intelligent semiconductor switch with integrated current measurement function

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,222,377 B2
- Document ID: US12222377B2
- Status: Granted
- Kind: B2
- Application number: 18/296,878
- Filed: 2023-04-06
- Published: 2023-11-23
- Granted: 2025-02-11
- Earliest claimed: 2022-05-20
- Assignees: Infineon Technologies AG
- Applicants: Infineon Technologies AG
- Inventors: Albino Pidutti; Andrea Baschirotto; Paolo Del Croce
- Web page: https://patentgrep.com/patent/US12222377B2

## CPC

- G01R 19/10: Measuring sum, difference or ratio
- H03K 17/122: {in field-effect transistor switches}
- H02M 1/0009: {Devices or circuits for detecting current in a converter}
- H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H03K 17/56: by the use, as active elements, of semiconductor devices (using diodes H03K17/74)
- G01R 19/0092: {Measuring current only}
- H02M 1/0006: {Arrangements for supplying an adequate voltage to the control circuit of converters}
- H03K 2217/0027: Measuring means of, e.g. currents through or voltages across the switch
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- 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)
- 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)

## Abstract

A method for current measurement in a switching converter is described herein. In accordance with one embodiment, the method includes switching a first transistor on and off in accordance with a logic signal, wherein a load current passes through the first transistor while it is switched on. The method further includes providing—by a second transistor—a sense current that is indicative of the load current, wherein the second transistor is coupled to the first transistor so that the first and the second transistors are switched on and off simultaneously. Further, the method includes determining an end of a switch-on phase of the second transistor, and providing a current sense signal that represents the sense current between a first time instant, which corresponds to the determined end of the switch-on phase, and a second time instant, at which the logic signal signals a switch-off of the first transistor.

## Claims

### Claim 1

A method comprising:
switching a first transistor on and off in accordance with a logic signal, with a load current passing through the first transistor while it is switched on;
providing a sense current that is indicative of the load current via a second transistor that is coupled to the first transistor such that the first and the second transistors are switched on and off simultaneously;
determining an end of a switch-on phase of the second transistor; and
providing a current sense signal that represents the sense current between a first time instant, which corresponds to the determined end of the switch-on phase, and a second time instant, at which the logic signal signals a switch-off of the first transistor.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
filtering the current sense signal using a low-pass filter.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
generating an error signal representing a difference between the filtered current sense signal and a reference value.

### Claim 4 (depends on 3)

The method of claim 3, further comprising:
generating a periodic signal which comprises a triangular pulse in each period;
comparing the periodic signal with the error signal using a comparator; and
generating the logic signal based on an output signal of the comparator.

### Claim 5 (depends on 1)

The method of claim 1,
wherein the logic signal is a modulated signal indicating on-times and off-times of the first transistor, and wherein a begin of each on-time triggers a respective switch-on phase of the second transistor.

### Claim 6 (depends on 1)

The method of claim 1, wherein determining the end of the switch-on phase of the second transistor comprises:
modifying a time value, indicating the end of the switch-on phase, based on a voltage value of a gate voltage of the first transistor, sampled at an end of a preceding switch-on phase, and a reference value.

### Claim 7

A circuit comprising:
a first transistor configured to provide a load current in accordance with a logic signal;
a sense transistor coupled to the first transistor and configured to provide a sense current that is indicative of the load current;
a control circuit that is configured to;
determine an end of a switch-on phase of the sense transistor; and
provide a current sense signal that represents the sense current between a first time instant, which corresponds to the determined end of the switch-on phase, and a second time instant at which the logic signal signals a switch-off of the first transistor.

### Claim 8 (depends on 7)

The circuit of claim 7,
wherein the control circuit comprises a switch configured to blank out the current sense signal from a third time instant, at which the logic signal signals a switch-on of the first transistor, and the first time instant.

### Claim 9 (depends on 7)

The circuit of claim 7, wherein the control circuit comprises:
a low pass filter configured to filter the current sense signal.

### Claim 10 (depends on 9)

The circuit of claim 9, wherein the control circuit further comprises:
an error amplifier configured to generate an error signal, representing a difference between the filtered current sense signal, and a reference value.

### Claim 11 (depends on 10)

The circuit of claim 10, wherein the control circuit further comprises:
a ramp generator configured to generate a periodic signal, which comprises a triangular pulse in each period; and
a comparator, configured to compare the periodic signal with the error signal,
wherein the control circuit is configured to generate the logic signal based on an output signal of the comparator.

### Claim 12 (depends on 7)

The circuit of claim 7, further comprising:
an inductor connected to the first transistor such that the load current passes through the inductor while the first transistor is switched on;
a free-wheeling element coupled to the inductor such that an inductor current can pass though the free-wheeling element while the first transistor is switched off; and
an electric load which is coupled to the first transistor via the inductor.