Current absorption management circuit, corresponding system and method

Patent metadata

Field	Value
Publication number	US-11764773-B2
Application number	US-202117545719-A
Country	US
Kind code	B2
Filing date	Dec 8, 2021
Priority date	Dec 11, 2020
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

Current absorption management for an electronic fuse coupled between an electrical supply source node and an electrical load node selectively controls a high current electronic switch and a low current electronic switch coupled in parallel between the electrical supply source node and the electrical load node. The high current and low current electronic switches are alternatively actuated: in a first mode where the high current electronic switch is turned on and the low current electronic switch is turned off, and in a second mode where the high current electronic switch is turned off and the low current electronic switch is turned on. Change to the second mode may be made in response to a standby state or a sensing of a lower current in the electrical load. Conversely, change to the first mode may be made in response to a sensing of a higher current in the electrical load.

First claim

The invention claimed is:

1. A circuit, comprising:
a first node configured to be coupled to an electrical supply source;
a second node configured to be coupled to an electrical load;
a third node configured to be coupled to a control node of an electronic switch that is coupled between the electrical supply source and the electrical load;
a secondary electronic switch coupled between the first node and the second node;
control logic circuitry configured to provide a first switch control signal applied through said third node to the control node of the electronic switch for controlling switching of the electronic switch between a conductive state for delivering a first current level to the electrical load from the electrical supply source, and a non-conductive state;
wherein said control logic circuitry is further configured to provide a second switch control signal applied to a control node of the secondary electronic switch for controlling switching of the secondary electronic switch between a conductive state for delivering a second current level to the electrical load from the electrical supply source, and a non-conductive state, wherein the second current level is lower than the first current level;
wherein the first switch control signal and the second switch control signal control the electronic switch and secondary electronic switch such that, alternately:
in a first mode of operation, the first switch control signal switches the electronic switch to the conductive state to deliver the first current level to the second node and the second switch control signal switches the secondary electronic switch to the non-conductive state; and
in a second mode of operation, the first switch control signal switches the electronic switch to the non-conductive state and the second switch control signal switches the secondary electronic switch to the conductive state to deliver the second current level to the second node i

wherein the electronic switch is a first conductivity type MOSFET device and the secondary electronic switch is a second conductivity type MOSFET device.

2. The circuit of claim 1 , further comprising a fourth node configured to receive a standby signal, wherein the control logic circuitry is configured to switch from said first mode of operation to said second mode of operation in response to assertion of said standby signal.

3. The circuit of claim 1 , further comprising:
current sensing circuitry configured to sense an intensity of current flowing through the electrical load; and
wherein the control logic circuitry is configured to switch from said first mode of operation to said second mode of operation in response to the current sensing circuitry detecting current flowing through the electrical load dropping to a lower threshold.

4. The circuit of claim 3 , wherein the current sensing circuitry comprises a sensing transistor having a control node coupled to said third node and a current path therethrough included in a current feedback line from said first node to a further node that is coupled to ground via a resistor.

5. The circuit of claim 3 , wherein the control logic circuitry is further configured to switch from said second mode of operation to said first mode of operation in response to the current sensing circuitry detecting current flowing through the electrical load increasing to an upper threshold.

6. The circuit of claim 1 , wherein the electronic switch is a higher power transistor for delivering the first current level and the secondary electronic switch is a lower power transistor for delivering the second current level.

7. A circuit, comprising:
a first node configured to be coupled to an electrical supply source;
a second node configured to be coupled to an electrical load;
a third node configured to be coupled to a control node of an electronic switch that is coupled between the electrical supply source and the electrical load;
a secondary electronic switch coupled between the first node and the second node;
control logic circuitry configured to provide a first switch control signal applied through said third node to the control node of the electronic switch for controlling switching of the electronic switch between a conductive state for delivering a first current level to the electrical load from the electrical supply source, and a non-conductive state;
wherein said control logic circuitry is further configured to provide a second switch control signal applied to a control node of the secondary electronic switch for controlling switching of the secondary electronic switch between a conductive state for delivering a second current level to the electrical load from the electrical supply source, and a non-conductive state, wherein the second current level is lower than the first current level;
wherein the first switch control signal and the second switch control signal control the electronic switch and secondary electronic switch such that, alternately:
in a first mode of operation, the first switch control signal switches the electronic switch to the conductive state to deliver the first current level to the second node and the second switch control signal switches the secondary electronic switch to the non-conductive state; and
in a second mode of operation, the first switch control signal switches the electronic switch to the non-conductive state and the second switch control signal switches the secondary electronic switch to the conductive state to deliver the second current level to the second node;

supply regulator circuitry having a first supply regulator section and a second supply regulator section, the second supply regulator section having lower energy absorption than the first supply regulator section; and
wherein the control logic circuitry is further configured to enable the first supply regulator section during the first mode of operation and alternatively enable the second supply regulator section during the second mode of operation.

8. The circuit of claim 7 , further comprising a fourth node configured to receive a standby signal, wherein the control logic circuitry is configured to switch from said first mode of operation to said second mode of operation in response to assertion of said standby signal.

9. The circuit of claim 7 , wherein the electronic switch is a higher power transistor for delivering the first current level and the secondary electronic switch is a lower power transistor for delivering the second current level.

10. A circuit, comprising:
a first node configured to be coupled to an electrical supply source;
a second node configured to be coupled to an electrical load;
a third node configured to be coupled to a control node of an electronic switch that is coupled between the electrical supply source and the electrical load;
a secondary electronic switch coupled between the first node and the second node;
control logic circuitry configured to provide a first switch control signal applied through said third node to the control node of the electronic switch for controlling switching of the electronic switch between a conductive state for delivering a first current level to the electrical load from the electrical supply source, and a non-conductive state;
wherein said control logic circuitry is further configured to provide a second switch control signal applied to a control node of the secondary electronic switch for controlling switching of the secondary electronic switch between a conductive state for delivering a second current level to the electrical load from the electrical supply source, and a non-conductive state, wherein the second current level is lower than the first current level;
wherein the first switch cont

Assignees

• St Microelectronics Srl

Inventors

• Castro Enrico
• Susinna Giovanni
• Randazzo Vincenzo
• Dondini Mirko
• Trecarichi Calogero Andrea

Classifications

• H02H3/087 Primary

  for DC applications · CPC title

• H03K17/0822 Primary

  in field-effect transistor switches · CPC title

• H02H5/041

  additionally responsive to excess current (H02H5/048 takes precedence) · CPC title

• H02H9/02

  responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} · CPC title