Constant Brightness LED Drive Communications Port
First Claim
1. A method for driving a light emitting diode (LED) and transmitting digital information using a single node of an integrated circuit device, said method comprising the steps of:
- generating a plurality of pulses from a single node of an integrated circuit device; and
coupling the plurality of pulses from the single node of the integrated circuit device to a light emitting diode (LED);
wherein the plurality of pulses from the single node of the integrated circuit device control light intensity from the LED and transmit digital information.
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Accused Products
Abstract
A light emitting diode (LED) is driven with a plurality of pulses having controllable pulse widths and positions within clock time periods that provide for both LED light intensity control and digital information communications from a single output node of an integrated circuit (IC) device. The LED light intensity is determined by the duty cycle of the pulses where the human eye integrates these light pulses from the LED into continuous light intensity levels. The digital information contained in the light output from the LED is detected by a photo-detector that converts the light pulses into electric signals that are demodulated and read by a circuit debugger and/or manufacturing test station. The aforementioned operations allow continuous visual display and data transmission using only one output node of the IC device. This is especially advantageous when using low pin count IC devices.
23 Citations
19 Claims
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1. A method for driving a light emitting diode (LED) and transmitting digital information using a single node of an integrated circuit device, said method comprising the steps of:
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generating a plurality of pulses from a single node of an integrated circuit device; and coupling the plurality of pulses from the single node of the integrated circuit device to a light emitting diode (LED); wherein the plurality of pulses from the single node of the integrated circuit device control light intensity from the LED and transmit digital information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An integrated circuit device, comprising:
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a digital processor and memory; a serial interface having an input coupled to the digital processor; a light emitting diode (LED) light intensity control circuit having an input coupled to the digital processor; a modulator having a first input coupled to an output of the serial interface and a second input coupled to an output of the LED light intensity control circuit; and a single node coupled to an output of the modulator. - View Dependent Claims (10, 11)
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12. A system for driving a light emitting diode (LED) and transmitting digital information using a single node of an integrated circuit device, said system comprising:
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an integrated circuit device generating a plurality of pulses from a single node thereof; and a light emitting diode (LED) coupled to the single node of the integrated circuit device; wherein the plurality of pulses from the single node of the integrated circuit device control light intensity from the LED and transmit digital information. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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Specification