Process transmitter having a step-up converter for powering analog components

• US 6,813,318 B1
• Filed: 04/30/1999
• Issued: 11/02/2004
• Est. Priority Date: 04/30/1999
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Tyson, David G., Roper, Weston T., Westfield, Brian L.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Kim, Kevin
• Application Number:
  US09/303,050
• Time in Patent Office: 2,013 Days
• Field of Search: 375/354, 375/295, 340/870.18, 340/870.37, 340/870.21
• US Class Current: 375/295
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 19/4185 characterised by the network communication

Abstract

A process transmitter suitable for coupling to a process loop. The process transmitter includes a power regulator adapted to receive a power signal on the process loop and to provide a first signal having a first voltage. Digital components of the process transmitter are electrically coupled to the power regulator to receive power from the first signal. A step-up converter is electrically coupled to the power regulator and receives the first signal. The step-up converter outputs a second signal having a second voltage larger than the first voltage. Analog components of the process transmitter are electrically coupled to the step-up converter to receive power from the second signal.

Claims

1. A process transmitter, comprising:

a power regulator adapted to receive a power signal, the power regulator generating a first signal based on the power signal, the first signal having a first voltage;

digital components electrically coupled to the power regulator to receive power from the first signal;

a step-up converter electrically coupled to the power regulator to input the first signal and output a second signal having a second voltage that is larger than the first voltage;

analog components electrically coupled to the step-up converter to receive power from the second signal; and

a start-up circuit electrically coupled to the power regulator to receive the first signal and electrically coupled to the step-up converter to activate the step-up converter after the first voltage has surpassed a first threshold voltage.

2. The process transmitter of claim 1, wherein the start-up circuit includes a comparator which compares the first signal to the first threshold voltage and controls a shutdown signal, provided to the step-up converter, as a function of the comparison.

3. The process transmitter of claim 1, wherein the start-up circuit includes a power-on-reset device.

4. A process transmitter, comprising:

a power regulator adapted to receive a power signal, the power regulator generating a first signal based on the power signal, the first signal having a first voltage;

digital components electrically coupled to the power regulator to receive power from the first signal;

a step-up converter electrically coupled to the power regulator to input the first signal and output a second signal having a second voltage that is larger than the first voltage;

analog components electrically coupled to the step-up converter through a selectively activated switch to receive power from the second signal; and

a start-up circuit electrically coupled to the power regulator to receive the first signal and electrically coupled to the switch to activate the switch after the first voltage has surpassed a first threshold voltage.

5. The process transmitter of claim 4, wherein the start-up circuit includes a comparator which compares the first signal to the first threshold voltage and controls a load enable signal, provided to the switch, as a function of the comparison.

6. A process transmitter, comprising:

a power regulator adapted to receive a power signal, the power regulator generating a first signal based on the power signal, the first signal having a first voltage;

digital components electrically coupled to the power regulator to receive power from the first signal;

a step-up converter electrically coupled to the power regulator to input the first signal and output a second signal having a second voltage that is larger than the first voltage;

analog components electrically coupled to the step-up converter through a selectively activated switch to receive power from the second signal; and

a start-up circuit electrically coupled to the power regulator to receive the first signal and electrically coupled to the step-up converter to activate the step-up converter after the first voltage has surpassed a first threshold voltage, and electrically coupled to the switch to activate the switch after the first voltage has surpassed a second threshold voltage.

7. A process transmitter suitable for coupling to a process loop, the transmitter comprising:

an electronics module, having;

a power regulator adapted to receive a power signal on the process loop and to provide a first signal having a first voltage; and

a first set of digital components electrically coupled to the power regulator to receive power from the first signal; and

a sensor module electrically coupled to the electronics module, the sensor module having;

a second set of digital components electrically coupled to the power regulator to receive power from the first signal;

a step-up converter electrically coupled to the power regulator, wherein the step-up converter receives the first signal and outputs a second signal having a second voltage, and wherein the second voltage is larger than the first voltage; and

analog components electrically coupled to the step-up converter to receive power from the second signal.