News Column

Researchers Submit Patent Application, "Maintaining the Resistor Divider Ratio during Start-Up", for Approval

August 20, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Bhattad, Ambreesh (Swindon, GB); Nikolov, Ludmil (Chippenham, GB); Kruiskamp, Marinus Wilhelmus ('s-Hertogenbosch, NL), filed on February 1, 2013, was made available online on August 7, 2014.

The patent's assignee is Dialog Semiconductor B.v.

News editors obtained the following quote from the background information supplied by the inventors: "(1) Technical Field

"The present document relates to start-up processes of electronic circuits. In particular, the present document relates to a method and system for maintaining a resistor voltage divider ratio during start-up using a dynamic circuit.

"(2) Background

"Prior art implementations of circuits as e.g. a low-dropout (LDO) voltage regulator using a feed-forward capacitor in parallel to a feedback resistor of a resistor voltage divider have the disadvantage that a voltage divider ratio is impacted by the feed-forward capacitor during start-up phase and clean start-up specification may not always being met.

"It is a challenge for engineers to design start-up processes of circuits as e.g. an LDO without the disadvantage cited above."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "A principal object of the present disclosure is to achieve a correct determination of the output voltage of a circuit by a start-up comparator.

"A further object of the disclosure is to avoid an output voltage drop (brown out) condition of the circuit as e.g. an LDO.

"A further object of the disclosure is to avoid any violation of a start-up specification.

"A further object of the disclosure is to achieve a clean start-up process.

"A further object of the disclosure is to maintain a constant voltage divider ratio during start-up.

"A further object of the disclosure is to use a dynamic circuit to manage the start-up process only during start-up.

"In accordance with the objects of this disclosure a method to maintain a resistive voltage divider ratio during start-up of any electronic circuit comprising a feed-forward capacitor across a feedback resistor of a resistive voltage divider using a dynamic start-up circuit has been disclosed. The method disclosed comprises the following steps: (1) providing an electronic circuit comprising a feed-forward capacitor across a first feedback resistor of a resistive voltage divider and a start-up circuit, (2) avoiding modification of resistive voltage divider ratio caused by feed-forward capacitor during start-up phase, (3) monitoring output voltage and finish start-up-phase when desired output voltage of the electronic circuit is reached, and (4) processing normal operation after start-up phase is finished wherein feed-forward capacitor is connected across the feedback resistor of the resistive voltage divider after end of start-up phase.

"In accordance with the objects of this disclosure a circuit to maintain a resistive voltage divider ratio during start-up of a LDO comprising a feed-forward capacitor across a feedback resistor using a dynamic start-up circuit has been achieved. The circuit disclosed comprises, the feed-forward capacitor, wherein a first plate of the feed-forward capacitor is connected to an output port of the LDO voltage, said resistive voltage divider, being connected between the output port of the LDO and ground, comprising the feedback resistor having a resistance R2 connected between the output port of the LDO and the voltage access point in-between the voltage divider having a fraction of the output voltage and further comprising a second resistor having a resistance R1, and a means to maintain a voltage level of the voltage access point across the feed-forward capacitor during start-up of the LDO.

"In accordance with the objects of this disclosure a circuit to maintain a resistive voltage divider ratio during start-up of any electronic circuit comprising a feed-forward capacitor across a feedback resistor and a resistive voltage divider using a dynamic start-up circuit, has been disclosed. The circuit disclosed firstly comprises: the feed-forward capacitor, wherein a first plate of the feed-forward capacitor is connected to an output port of the circuit and a second plate is connected to a voltage access point of the resistive voltage divider after the start-up phase of the electronic circuit is finished and said resistive voltage divider, being connected between an output port of the circuit and ground, comprising the feedback resistor having a resistance R2 connected between the output port of the circuit and the voltage access point in-between the voltage divider having a fraction of the output voltage and further comprising a second resistor having a resistance R1. Furthermore the circuit comprises: a start-up comparator detecting if the start-up phase is finished by comparing a voltage representing the output voltage of the electronic circuit with a reference voltage and a means to maintain a voltage level of the voltage access point across the feed-forward capacitor during start-up of the circuit, wherein the means to maintain a voltage level of the voltage access point comprises switching means to connect or disconnect components of the circuit at beginning and end of the start-up process, wherein the switching means are activated by the start-up comparator.

BRIEF DESCRIPTION OF THE DRAWINGS

"In the accompanying drawings forming a material part of this description, there is shown:

"FIG. 1 shows the basic elements of a second embodiment of a start-up circuit of the present disclosure applied to a LDO.

"FIG. 2 illustrates a third embodiment of a start-up circuit of the present disclosure applied to a LDO.

"FIG. 3 illustrates a flowchart of a method to maintain a resistive voltage divider ratio during start-up of an electronic circuit comprising a feed-forward capacitor across a feedback resistor using a dynamic start-up circuit.

"FIG. 4 shows basic elements of an embodiment of a start-up circuit of the present disclosure applied for example to a LDO."

For additional information on this patent application, see: Bhattad, Ambreesh; Nikolov, Ludmil; Kruiskamp, Marinus Wilhelmus. Maintaining the Resistor Divider Ratio during Start-Up. Filed February 1, 2013 and posted August 7, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5242&p=105&f=G&l=50&d=PG01&S1=20140731.PD.&OS=PD/20140731&RS=PD/20140731

Keywords for this news article include: Electronics, Dialog Semiconductor B.v..

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Electronics Newsweekly


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters