Ferrite stabilized LED drive
First Claim
1. An oximeter diode-driving device, comprising:
- a diode;
a transistor operative to controllably connect current to the diode;
a current sensing element that senses at least part of the current;
a feedback amplifier operative to control the connecting of current by the transistor according to the current sensed by the current sensing element; and
an inductor disposed in series with the current sensing element.
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Accused Products
Abstract
An oximeter diode-driving device has a diode, a transistor operative to controllably connect current to the diode, a current sensing resistor that senses at least part of the current, a feedback amplifier operative to control the connecting of current by the transistor according to the current sensed by the current sensing resistor, and an inductor disposed in series with the current sensing resistor. A method of driving a current through the diode of an oximeter includes driving a current through the diode by connecting the current to the diode, controlling the connecting using a feedback type amplifier, the feedback type amplifier having a current source that uses a current-limiting resistor, and adding phase lead to a current passing through the current-limiting resistor.
121 Citations
11 Claims
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1. An oximeter diode-driving device, comprising:
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a diode;
a transistor operative to controllably connect current to the diode;
a current sensing element that senses at least part of the current;
a feedback amplifier operative to control the connecting of current by the transistor according to the current sensed by the current sensing element; and
an inductor disposed in series with the current sensing element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
a feedback capacitor disposed between the transistor and an inverting input of the feedback amplifier; and
a feedback element disposed in parallel with the feedback capacitor.
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10. An oximeter diode-driving device according to claim 9, wherein a capacitance value of the feedback capacitor and a resistance value of the feedback element are set to define an on/off time constant for the feedback amplifier.
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11. An oximeter diode-driving device according to claim 10, wherein the capacitance value of the feedback capacitor is set to counteract a phase lag caused by an input capacitance of the feedback amplifier.
Specification