High speed, high current pulsed driver circuit
Various technologies presented herein relate to driving a LED such that the LED emits short duration pulses of light. This is accomplished by driving the LED with short duration, high amplitude current pulses. When the LED is driven by short duration, high amplitude current pulses, the LED emits light at a greater amplitude compared to when the LED is driven by continuous wave current.
1. A system comprising:
a light emitting diode (LED); and
a LED driver circuit that comprises:
an nMOS transistor; and
a pMOS transistor, wherein gates of the nMOS transistor and the pMOS transistor are electrically connected to a pulsed trigger source that emits a pulsed trigger signal, wherein the LED driver circuit is configured to deliver pulsed current to the LED as a function of the pulsed trigger signal, wherein the pulsed current has a peak amplitude that is greater than a maximum continuous forward current rating of the LED, the LED emits pulses of light in correspondence with the pulsed current.
2. The system of claim 1 , wherein the peak amplitude is about 10 to about 30 times greater than the maximum continuous forward current rating of the LED.
3. The system of claim 1 , wherein the peak amplitude current is up to about 30 times greater than the maximum continuous forward current rating of the LED.
4. The system of claim 1 , wherein the pulsed current is short duration pulsed current, wherein each pulse in the pulsed current has a duration of between 5 ns and 20 ns.
5. The system of claim 1 , further comprising the pulsed trigger source, the pulsed trigger source configured to output the pulsed trigger signal with an amplitude of about 5 volts when high.
6. The system of claim 5 , further comprising:
a direct current (DC) voltage source; and
a capacitor placed in parallel with the DC voltage source, the capacitor electrically connected to the LED driver circuit.
7. The system of claim 6 , wherein an anode of the LED is connected to ground when the nMOS transistor is switched on and the pMOS transistor is switched off.
8. The system of claim 7 , wherein the DC voltage source is connected to ground when the nMOS transistor is switched on and the pMOS transistor is switched off.
9. The system of claim 1 , wherein the LED is a high power LED, wherein the high power LED is rated with a current density of at least 0.35 amperes/mm 2 .
10. An apparatus comprising:
a light emitting diode (LED); and
a driver circuit that comprises:
an nMOS transistor; and
a pMOS transistor, where gates of the nMOS transistor and the pMOS transistor are coupled to one another such that the nMOS transistor and the pMOS transistor are activated by a common input signal, wherein the driver circuit drives the LED with short duration, high-amplitude current pulses, wherein the driver circuit is a bipolar driver circuit, each pulse in the short duration, high-amplitude current pulses has a duration of between 5 and 100 ns, and wherein each pulse in the short duration, high-amplitude current pulses has an amplitude that is greater than a maximum continuous forward current rating of the LED.
11. The apparatus of claim 10 , the driver circuit causes the LED to emit short duration optical pulses, wherein each pulse in the short duration optical pulses has a duration of between 5 and 100 ns.
12. The apparatus of claim 10 , further comprising a second driver circuit that is placed electrically in parallel with the driver circuit, the driver circuit and the second driver circuit operate in conjunction to drive the LED.
13. The apparatus of claim 10 , further comprising:
a second LED; and
a second driver circuit that drives the second LED, the driver circuit and the second driver circuit are independently triggerable to drive the LED and the second LED, respectively.
14. The apparatus of claim 13 , the LED and the second LED emit light of different colors.
15. The apparatus of claim 13 , further comprising a matrix of switches that are configured to connect and disconnect portions of the apparatus.
16. A method comprising:
electrically arranging a plurality of driver circuits in parallel with one another, wherein each driver circuit in the plurality of driver circuits is configured to emit pulsed current, and further wherein each driver circuit comprises:
an nMOS transistor; and
a pMOS transistor, wherein gates of the nMOS transistor and the pMOS transistor are electrically connected to a pulsed trigger source that emits a pulsed trigger signal, the light emitting diode (LED) driver circuit delivers the pulsed current as a function of the pulsed trigger signal; and
electrically coupling the plurality of driver circuits to at least one LED, such that the pulsed current emitted from the plurality of driver circuits causes the LED to emit pulses of light, wherein the pulsed current has a peak amplitude that is greater than a maximum continuous forward current rating of the LED, the LED emits pulses of light in correspondence with the pulsed current.
17. The method of claim 16 , wherein the plurality of driver circuits are bipolar driver circuits.
18. The method of claim 16 , wherein the peak amplitude is about 10 to about 30 times greater than the maximum continuous forward current rating of the LED.
19. The method of claim 16 , wherein the peak amplitude current is up to about 30 times greater than the maximum continuous forward current rating of the LED.
20. The method of claim 16 , wherein the pulsed current is short duration pulsed current, wherein each pulse in the pulsed current has a duration of between 5 ns and 20 ns.