Remote input/output (RIO) smart sensor analog-digital chip

• US 6,744,376 B1
• Filed: 08/26/1999
• Issued: 06/01/2004
• Est. Priority Date: 08/26/1998
• Status: Expired due to Fees

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Pascalidis, Nikolaos P.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): DANG, HUNG Q
• Application Number:
  US09/383,911
• Time in Patent Office: 1,741 Days
• Field of Search: 340/870.13, 340/870.16, 340/501, 340/870.21, 250/332, 307/116, 333/661.2
• US Class Current: 340/870.21
• CPC Class Codes: G08C 15/00 Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path

Abstract

An analog-digital, radiation-hardened, low-power Smart Sensor Data Acquisition and Control chip, specifically designed and developed for Spacecraft/Instrument Housekeeping and Controls. Sensor data (Temperatures, Voltages, Currents, Pressure, Digitals) are continuously measured, digitized, stored, and transmitted, and Control Actions (DACS, Timers, Digitals) are activated, through a standard bi-directional, digital serial bus (I²C). The chip also offers a Custom or Standard (like PCI) parallel bus interface for parallel readout internally communicating to the serial bus. The chip essentially eliminates spacecraft harness, and greatly simplifies system design.

Claims

1. An integrated circuit for use in distributed data collection in a spacecraft comprising:

a plurality of ports for receiving sensor signals, said ports being connected to a plurality of sensors in the spacecraft wherein at least one of said plurality of sensors is a temperature sensor wherein a temperature measurement does not require a voltage reference due to the presence of a low temperature coefficient resistor external to said integrated circuit;

a multiplexer having a plurality of inputs and an output, each of said ports being connected to one of said inputs of said multiplexer;

an analog-to-digital converter having an input and an output, said input of said analog-to-digital converter being connected to said output of said multiplexer, said analog-to-digital converter comprising a radiation-hardened comparator;

a radiation-hardened voltage reference connected to said analog-to-digital converter;

a memory connected to said output of said analog-to-digital converter; and

a serial bus connected to said memory.

2. An integrated circuit for use in distributed data collection in accordance with claim 1, further comprising a plurality of amplifiers connected between said plurality of ports and said inputs to said multiplexer.

3. An integrated circuit for use in distributed data collection in accordance with claim 1 further comprising a parallel bus connected to said memory.

4. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said at least one temperature sensor is a thermistor.

5. An integrated circuit for use in distributed data collection in accordance with claim 1 herein said plurality of sensors include voltage sensors.

6. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said plurality of sensors include current sensors.

7. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said plurality of sensors include radiation sensors.

8. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said plurality of sensors include pressure sensors.

9. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said plurality of sensors include at least two sensors from the group of a voltage sensor, a current sensor, a radiation sensor, and a pressure sensor.

10. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said multiplexer is an analog multiplexer.

11. An integrated circuit for use in distributed data collection in accordance with claim 1 wherein said serial bus is an I²C serial bus.

12. An integrated circuit for use in distributed data-collection in accordance with claim 1 wherein said integrated circuit is radiation-hardened.

13. An integrated circuit for use in distributed data collection in a spacecraft comprising a plurality of sensors, the integrated circuit comprising:

a plurality of ports connected to said plurality of sensors in the spacecraft wherein at least one of said plurality of sensors is a temperature sensor wherein a temperature measurement does not require a voltage reference due to the presence of a low temperature coefficient resistor located external to said integrated circuit;

a multiplexer connected to each of said plurality of ports;

an analog-to-digital converter connected to said multiplexer;

a memory connected to said analog-to-digital converter; and

a serial bus connected to said memory.

14. An integrated circuit in accordance with claim 13 wherein said sensors include at least two from the group of a temperature sensor, a voltage sensor, a pressure sensor, a current sensor, and a radiation sensor.