Electronic fuse

Patent metadata

Field	Value
Publication number	US-10424908-B2
Application number	US-201715465280-A
Country	US
Kind code	B2
Filing date	Mar 21, 2017
Priority date	Mar 21, 2017
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

A device includes a current monitor, an electronic switch, an energy harvester, and a load controller. The current monitor monitors current drawn by a load coupled to the device and generate an alert signal in response to the monitored current exceeding a predefined threshold value. The electronic switch decouples a battery from the load in response to the alert signal, the electronic switch being electrically disconnected from a negative terminal of the battery coupled to the device. The energy harvester stores energy from the battery while the load is drawing current from the battery. The load controller receives, from the energy harvester, the stored energy from the energy harvester and generates a voltage to power the current monitor to reset the alert signal while the battery is decoupled from the load.

First claim

What is claimed is:

1. A device, comprising:
a current monitor to monitor current drawn by a load coupled to the device and generate an alert signal in response to the monitored current exceeding a predefined threshold value;
an electronic switch to decouple a battery from the load in response to the alert signal, the electronic switch being electrically disconnected from a negative terminal of the battery coupled to the device;
an energy harvester to store energy from the battery while the load is drawing current from the battery; and
a load controller to receive, from the energy harvester, the stored energy from the energy harvester and to generate a voltage to power the current monitor to reset the alert signal while the battery is decoupled from the load.

2. The device according to claim 1 , wherein the device further includes a shunt resistor between the battery and the load, wherein the current monitor monitors current across the shunt resistor as a basis to generate the alert signal.

3. The device according to claim 2 , wherein the current monitor is comprised of a comparator to compare the current across the shunt resistor to the predefined threshold value, the current monitor generating the alert signal in response to the current across the shunt resistor exceeding the predefined threshold value.

4. The device according to claim 1 , wherein the energy harvester includes a charge pump to store the energy from the battery coupled to the device while the load is drawing current from the battery.

5. The device according to claim 1 , wherein the energy harvester includes a capacitor to store the energy from the battery coupled to the device while the load is drawing current from the battery.

6. The device according to claim 1 , wherein the electronic switch is a first transistor, the device further comprising:
a second transistor; and
an interconnection controller to, in a first configuration, selectively couple the first transistor to the energy harvester and configure the second transistor as the electronic switch, and to, in a second configuration, selectively couple the second transistor to the energy harvester and configure the first transistor as the electronic switch.

7. The device according to claim 6 , where the first and second transistors are metal-oxide-semiconductor field-effect (MOSFET) transistors.

8. The device according to claim 1 , wherein the load controller is comprised of a low dropout (LDO) regulator to generate the voltage that is used to power the current monitor and the electronic switch in response to the electronic switch selectively decoupling the load from the device.

9. The device according to claim 1 , wherein the device is an automotive fuse.

10. A method, comprising:
monitoring, with a current monitor, current drawn by a load coupled to the device;
storing, with an energy harvester, energy from a battery coupled to the device while the load is drawing current from the battery;
generating, with the current monitor, an alert signal in response to the monitored current exceeding a predefined threshold value;
selectively decoupling, with an electronic switch that is electrically disconnected from a negative terminal of a battery, the battery from the load in response to the alert signal; and
generating, with the load controller, a voltage from the stored energy to power the current monitor to reset the alert signal while the battery is decoupled from the load.

11. The method according to claim 10 , wherein the monitoring comprises:
monitoring the current across a shunt resistor between the battery and the load; and
generating the alert signal in response to the monitored current across the shunt resistor exceeding the predefined threshold value; and
decoupling the battery from the load in response to the alert signal.

12. The method according to claim 11 , further comprising comparing the current across the shunt resistor to the predefined threshold value as a basis to generate the alert signal.

13. The method according to claim 10 , wherein the storing is performed with a charge pump.

14. The method according to claim 10 , wherein the storing is performed by a capacitor.

15. The method according to claim 10 , wherein the electronic switch is a first transistor, the method further comprising:
selectively coupling, in a first configuration, the first transistor to the energy harvester;
selectively configuring, in the first configuration, a second transistor to selectively couple and decouple the battery and the load;
selectively coupling, in a second configuration, the second transistor to the energy harvester; and
selectively configuring, in the second configuration, the first transistor to selectively couple and decouple the battery and the load.

16. The method according to claim 15 , where the first and second transistors are metal-oxide-semiconductor field-effect (MOSFET) transistors.

17. The method according to claim 10 , wherein the generating the voltage is performed by a low dropout (LDO) regulator.

18. The method according to claim 10 , wherein the device is an automotive fuse.

19. A device, comprising:
a current monitor to monitor current drawn by a load coupled to the device and generate an alert signal in response to the monitored current exceeding a predefined threshold value;
a first electronic switch in series between a battery and the load;
a second electronic switch in series between the battery and the load;
an energy harvester to store energy from the battery while the load is drawing current from the battery;
a load controller to receive, from the energy harvester, the stored energy and to generate a voltage to power the current monitor to reset the alert signal while the battery is decoupled from the load; and
an interconnection controller to, in a first configuration, selectively couple the first electronic switch to the energy harvester and configure the second electronic switch to selectively decouple the battery from the load in response to the alert signal, and, in a second configuration, selectively couple the second electronic switch to the energy harvester and configure the first electronic switch to selectively decouple the battery from the load in response to the alert signal.

20. The device according to claim 19 , further comprising a shunt resistor between the battery and the load, wherein the current monitor monitors current across the shunt resistor as a basis to generate the alert signal.

21. An electronic fuse, comprising:
an energy harvester, including:
an input to accept and store energy from a battery while a load is drawing current from the battery through the electronic fuse;
an output to provide the stored energy when the battery and load are disconnected; and
a virtual ground connection to act as a ground terminal of the battery for the energy harvester.

22. The electronic fuse according to claim 21 , wherein the energy harvester is comprised of a charge pump to store the energy from the battery while the load is drawing current from the battery.

23. The electronic fuse according to claim 21 , wherein the output of the energy harvester is coupled to a low-dropout regulator to input the stored energy and output a common current voltage based on the stored energy.

24. The electronic fuse according to claim 21 , wherein the input of the energy harvester is coupled to an interconnection controller, the interconnection controller c

Assignees

• Texas Instruments Inc

Inventors

• Reddy Kambham Taraka Rama Chandra
• Steinmetz Karl-Heinz
• Kelenvölgyi Balázs

Classifications

• H02H3/06

  with automatic reconnection · CPC title

• H02H1/06

  Arrangements for supplying operative power {(power supply arrangements in general G05F, H02M)} · CPC title

• H02H3/04 Primary

  with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned {(watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18)} · CPC title

• H02H3/087

  for DC applications · CPC title

• G05F5/00

  Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output · CPC title