Voltage supply for a sensor unit and acceleration sensor unit with such a voltage supply

• US 6,459,245 B1
• Filed: 02/05/2001
• Issued: 10/01/2002
• Est. Priority Date: 08/16/2000
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Mader, Gerhard
• Primary Examiner(s): VU, BAO Q
• Application Number:
  US09/776,962
• Publication Number:
  US 20020021112A1
• Time in Patent Office: 603 Days
• Field of Search: 330/174, 330/69, 330/253, 323/266
• US Class Current: 323/266
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: H02J 1/02 Arrangements for reducing harmonics or ripples
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles

Abstract

A voltage supply unit which operates at an internal switching frequency and has a capacitor connected in parallel with its output is connected to the input of a sensor unit operating at an internal switching frequency. The connecting line contains a resistor which, together with a capacitor connected in parallel with the input, forms a filter.

Claims

1. A voltage supply for a sensor unit, comprising:

a voltage supply unit operating at an internal switching frequency and having an output;

a first capacitor connected in parallel with said output forming a branch point;

a sensor unit operating at an internal switching frequency and having a power supply input;

at least one second capacitor connected in parallel with said power supply input forming another branch point;

a line connecting said output of said voltage supply unit to said power supply input of said sensor unit;

a filter having a filter component contained between said branch points of said capacitors in said line; and

said filter component being formed by a resistor connected together with said second capacitor being connected in parallel with said power supply input of said sensor to form said filter.

2. The voltage supply according to claim 1, wherein:

said sensor unit is one of a plurality of sensor units connected in parallel on said line.

3. The voltage supply according to claim 2, wherein:

said resistor forming part of said filter is common to all of said sensor units.

4. The voltage supply according to claim 1, wherein:

said second capacitor connected in parallel with said power supply input of said sensor unit is a ceramic capacitor.

5. The voltage supply according to claim 2, wherein:

said second capacitor connected in parallel with said power supply input of said sensor unit is a ceramic capacitor.

6. The voltage supply according to claim 3, wherein:

said second capacitor connected in parallel with said power supply input of said sensor unit is a ceramic capacitor.

7. The voltage supply according to claim 1, wherein:

said second capacitor connected in parallel with said power supply of said sensor unit is disposed physically close to said power supply input.

8. The voltage supply according to claim 1, including:

a microcontroller having a reference voltage input connected to said line and connected on said line in parallel with said sensor unit.

9. The voltage supply according to claim 8, wherein:

said microcontroller contains an A/D converter for converting analog output signals from said sensor unit into digital output signals.

10. An acceleration sensor unit for an occupant protection system in a motor vehicle including a voltage supply, comprising:

a voltage supply unit operating at an internal switching frequency and having an output;

a first capacitor connected in parallel with said output forming a branch point;

a sensor unit operating at an internal switching frequency and having a power supply input;

at least one second capacitor connected in parallel with said power supply input forming another branch point;

a line connecting said output of said voltage supply unit to said power supply input of said sensor unit;

a filter having a filter component contained between said branch points of said capacitors in said line; and

said filter component being formed by a resistor connected together with said second capacitor being connected in parallel with said power supply input of said sensor to form said filter.