Nanosecond Pulsed, Large-Array, Light Emitting Diode Light Source

Kurzfassung

Nanosecond LED light sources require active carrier sweep‐out drivers in order to reduce the optical fall time down to a few nanoseconds. For applications in direct time‐of‐flight systems, it is aimed for a high power LED spotlight capable of emitting 4–8 ns pulses. Therefore, six selected LED driver circuits with 3 A peak current are compared and discussed in terms of pulse shape, efficiency and scalability for a large array spotlight. Inductive sweep‐out drivers and totem‐pole drivers for single LEDs achieved optical fall times between 2.5 and 5.3 ns at 6 ns pulse width (fwhm). A timing and power analysis on a spotlight consisting of 89 LEDs demonstrates the feasibility of the totem‐pole driver in a 62 mW array at 6 ns pulse width and a pulse frequency of 1 MHz.