Sensor communication discrete control considering EMC compliance for restraint control module

Patent metadata

Field	Value
Publication number	US-12395166-B2
Application number	US-202016892830-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Jun 4, 2020
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

An electronic control unit for a restraint control module comprises a PSI5 communications interface configured to communicate with a remote sensor using a current-modulated signal with PSI5 compliance upon a two-wire interconnection. The PSI5 communications interface includes a signal driver configured to apply a signal voltage to a first signal terminal for driving current to the remote sensor via the two-wire interconnection. The PSI5 communications interface also includes a second signal terminal providing a return path for the current; and a resistor within the return path of the PSI5 communications interface. Several different alternative impedance balancing and damping circuits are provided to provide the resistor. The alternative impedance balancing and damping circuits include passive and active resistors. The impedance balancing and damping circuit may also provide current protection against damage due to fault currents. A method for operating a PSI5 communications interface of a restraint control module is also provided.

First claim

What is claimed is:

1. An electronic control unit comprising:
a Peripheral Sensor Interface 5 (PSI5) communications interface configured to communicate with a remote sensor using a current-modulated signal with PSI5 compliance upon a two-wire interconnection, the PSI5 communications interface including:
a signal driver configured to apply a signal voltage to a first signal terminal for driving current to the remote sensor via the two-wire interconnection;
a second signal terminal providing a return path for the current; and
a resistor within the return path of the PSI5 communications interface to induce a balance voltage on the second signal terminal, wherein the balance voltage has a magnitude corresponding to a magnitude of the signal voltage and an opposite polarity thereof, and wherein the resistor is defined by a drain-source on resistance of a field effect transistor having a gate terminal connected to the first signal terminal.

2. A restraint control module for a motor vehicle comprising the electronic control unit of claim 1 .

3. The electronic control unit according to claim 1 , wherein the resistor is connected between the second signal terminal and a chassis ground.

4. The electronic control unit according to claim 1 , wherein the gate terminal is connected directly to the first signal terminal of the PSI5 communications interface.

5. The electronic control unit according to claim 4 , further comprising a current limiting resistor connected between the gate terminal and the first signal terminal of the PSI5 communications interface.

6. An electronic control unit comprising:
a Peripheral Sensor Interface 5 (PSI5) communications interface configured to communicate with a remote sensor using a current-modulated signal with PSI5 compliance upon a two-wire interconnection, the PSI5 communications interface including:
a signal driver configured to apply a signal voltage to a first signal terminal for driving current to the remote sensor via the two-wire interconnection;
a second signal terminal providing a return path for the current;
a resistor within the return path of the PSI5 communications interface to induce a balance voltage on the second signal terminal, wherein the balance voltage has a magnitude corresponding to a magnitude of the signal voltage and an opposite polarity thereof, and wherein the resistor is defined by a drain-source on resistance of a field effect transistor; and
a switch configured to limit an amount of current between the second signal terminal and a ground.

7. The electronic control unit according to claim 6 , further comprising a current sensor configured to detect the amount of current between the second signal terminal and the ground; and
wherein the switch is controlled by the current sensor.

8. The electronic control unit according to claim 6 ,
wherein the switch is configured to selectively assert or de-assert a control voltage upon a gate of the field effect transistor to drive the field effect transistor between a low impedance state and a high impedance state.

9. The electronic control unit according to claim 1 , further comprising a signal amplifier having a signal input and a signal output, with the signal input coupled to the first signal terminal and the signal output coupled to the second signal terminal through the resistor.

10. A method for operating a Peripheral Sensor Interface 5 (PSI5) communications interface of an electronic control unit, the method comprising:
applying a signal voltage to a first signal terminal of the PSI5 communications interface to drive a signal current to a remote sensor via a two-wire interconnection;
receiving the signal current from the remote sensor by a second signal terminal of the PSI5 communications interface providing a return path for the signal current;
inducing a balance voltage upon the second signal terminal by a resistor within the return path, wherein the balance voltage has a magnitude corresponding to a magnitude of the signal voltage and an opposite polarity thereof, and wherein the resistor is defined by a drain-source on resistance of a field effect transistor; and
selectively changing a resistance of the resistor as a function of the signal voltage.

11. The method according to claim 10 , wherein the electronic control unit is configured for operation within a restraint control module for a motor vehicle.

12. The method according to claim 10 , wherein the resistor is connected between the second signal terminal and a chassis ground.

13. The method according to claim 10 ,
wherein selectively changing the resistance of the resistor further comprises selectively asserting a gate of the field effect transistor by the signal voltage.

14. The method according to claim 10 , further comprising:
sensing the signal current; and
driving the return path to a high-impedance state in response to the signal current exceeding a current threshold voltage.

15. The method according to claim 14 ,
wherein driving the return path to the high-impedance state further comprises selectively de-asserting a gate of the field effect transistor in response to the signal current exceeding the current threshold voltage.

16. The method according to claim 10 , wherein inducing the balance voltage upon the second signal terminal further comprises:
applying a bias signal to the second signal terminal by a signal amplifier, with the bias signal being a function of the signal voltage.

Assignees

• Veoneer Us Inc
• Veoneer Us Safety Systems Llc

Inventors

• Koch Stuart
• Colarossi Vincent
• Hunt Nick
• Campbell Michael
• Scott Grant

Classifications

• H04L12/40

  Bus networks · CPC title

• H04L2012/40273

  the transportation system being a vehicle · CPC title

• H04Q9/00

  Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom · CPC title

• H04L67/12

  specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks · CPC title

• B60R21/01554

  Seat position sensors · CPC title