Voltage detector with trigger based on output load currency
AssigneeAnalog Devices, Inc.
InventorsPeter S. Henry, Evaldo M. Miranda
Life of this patent
Estimating the term…
Abstract
An alarm based upon the voltage across a linear regulator's pass transistor and the regulator's load current alerts operational circuitry which obtains power through the regulator when the voltage across the pass transistor may be insufficient for proper voltage regulation. The alarm's trigger voltage is adjusted in response to variations in the regulator's output current.
Claims23
An electronic system, comprising:
- a linear voltage regulator having a pass transistor with an input terminal connected to receive an unregulated voltage and an output terminal providing load current at a regulated output voltage,
- a voltage sensor connected across the input and output terminals of said pass transistor to sense the difference between said regulated and unregulated voltages,
- an alarm circuit including circuitry connected to establish a trigger voltage indicative of the regulator's imminent loss of regulation, and a current sensor connected to sense said load current and to adjust said trigger voltage in response to changes in said load current, said alarm circuit connected to activate an alarm signal whenever the voltage sensed by said voltage sensor equals said trigger voltage, and
- a controller which takes preventive and corrective measures in response to the activation of said alarm circuit.
A linear voltage regulator having a pass transistor with an input terminal connected to an unregulated voltage source and an output terminal providing load current at a regulated output voltage, comprising:
- a voltage sensor connected across the input and output terminals of said pass transistor to sense the difference between said regulated and unregulated voltages, and
- an alarm circuit including circuitry connected to establish a trigger voltage indicative of the regulator's imminent loss of regulation and a current sensor connected to sense said load current and to adjust said trigger voltage in response to changes in said load current, said alarm circuit connected to activate an alarm signal whenever the voltage sensed by said voltage sensor equals said trigger voltage.
A linear voltage regulator having a pass transistor with an input terminal connected to an unregulated voltage and an output terminal providing load current at a regulated output voltage, comprising:
- a voltage sensor having first and second input terminals respectively connected across the input and output terminals of said pass transistor to sense the difference between said regulated and unregulated voltages,
- an alarm circuit including circuitry connected to establish a trigger voltage indicative of the regulator's imminent loss of regulation and a current sensor connected to sense said load current and to adjust said trigger voltage in response to changes in said load current, said alarm circuit connected to activate an alarm signal whenever the voltage sensed by said voltage sensor equals a trigger voltage, and
- a trigger offset interposed in series between the pass transistor's output terminal and the voltage sensor's second input terminal so that the voltage sensor senses the sum of voltages across the pass transistor and trigger offset.
Dependencies are inferred from the claim text.