Figure 1.
The basic structure of the LED driver of type I with the possibility to pulse the output.
Figure 1.
The basic structure of the LED driver of type I with the possibility to pulse the output.
Figure 2.
The simulation circuit. From top to bottom: the control signal of the pulsing switch (turquoise), the control signal of the main switch (blue), the load current (violet), the current through the coil (red), and the change in the current through the coil (red).
Figure 2.
The simulation circuit. From top to bottom: the control signal of the pulsing switch (turquoise), the control signal of the main switch (blue), the load current (violet), the current through the coil (red), and the change in the current through the coil (red).
Figure 3.
The simulation circuit. From top to bottom: the control signal of the pulsing switch (turquoise), the control signal of the main switch (blue), the load current (violet), the current through the coil (red), and the change in the current through the coil (red).
Figure 3.
The simulation circuit. From top to bottom: the control signal of the pulsing switch (turquoise), the control signal of the main switch (blue), the load current (violet), the current through the coil (red), and the change in the current through the coil (red).
Figure 4.
From top to bottom: the input voltage (green); the control signal of the pulsing switch (turquoise); the control signal of the main switch (blue); the load current (violet); the current through the coil (red); the change in the current through the coil (red).
Figure 4.
From top to bottom: the input voltage (green); the control signal of the pulsing switch (turquoise); the control signal of the main switch (blue); the load current (violet); the current through the coil (red); the change in the current through the coil (red).
Figure 5.
Simulation circuit.
Figure 5.
Simulation circuit.
Figure 6.
From top to bottom: current through LED3 (brown), current through LED2 (violet), current through LED1 (dark violet), control signal of main switch (dark blue), control signal of LED3 (turquoise), control signal of LED2 (blue), control signal of LED1 (green), and change in current through coil (red).
Figure 6.
From top to bottom: current through LED3 (brown), current through LED2 (violet), current through LED1 (dark violet), control signal of main switch (dark blue), control signal of LED3 (turquoise), control signal of LED2 (blue), control signal of LED1 (green), and change in current through coil (red).
Figure 7.
(a) First variation. (b) Second variation.
Figure 7.
(a) First variation. (b) Second variation.
Figure 8.
Combination of three converters of type I.
Figure 8.
Combination of three converters of type I.
Figure 9.
Influence of parasitic load inductance. From top to bottom: ripple current through L1 (red), current through load (dark violet), voltage across S2 (blue), control signal of S2 (turquoise), voltage across S1 (green), and parasitic load inductance 1 µH without and with RC snubber of 10 Ω and 10 nF across S2.
Figure 9.
Influence of parasitic load inductance. From top to bottom: ripple current through L1 (red), current through load (dark violet), voltage across S2 (blue), control signal of S2 (turquoise), voltage across S1 (green), and parasitic load inductance 1 µH without and with RC snubber of 10 Ω and 10 nF across S2.
Figure 10.
From top to bottom: ripple current through L1 (red), current through load (dark violet), voltage across S2 (blue), control signal of S2 (turquoise), voltage across S1 (green), and parasitic load inductance of 1 µH twice with RC snubber with 10 Ω and 10 nF across S2 and across load.
Figure 10.
From top to bottom: ripple current through L1 (red), current through load (dark violet), voltage across S2 (blue), control signal of S2 (turquoise), voltage across S1 (green), and parasitic load inductance of 1 µH twice with RC snubber with 10 Ω and 10 nF across S2 and across load.
Figure 11.
Driving stage II.
Figure 11.
Driving stage II.
Figure 12.
Start-up and pulsing information. From top to bottom: the current through the LEDs (dark violet), the information (blue), and the current through the coil (red).
Figure 12.
Start-up and pulsing information. From top to bottom: the current through the LEDs (dark violet), the information (blue), and the current through the coil (red).
Figure 13.
Start-up and pulsing information. From top to bottom: the current through the LEDs (dark violet), the information (blue), and the current through the coil (red).
Figure 13.
Start-up and pulsing information. From top to bottom: the current through the LEDs (dark violet), the information (blue), and the current through the coil (red).
Figure 14.
(a) A clock frequency of 500 kHz. From top to bottom: the current through the load (dark violet); the control signal of S2 (black); the control signal of S1 (turquoise); the current through the inductor (red). (b) A clock frequency of 1 MHz. From top to bottom: the current through the load (dark violet); the control signal of S2 (black); the control signal of S1 (turquoise); the current through the inductor (red).
Figure 14.
(a) A clock frequency of 500 kHz. From top to bottom: the current through the load (dark violet); the control signal of S2 (black); the control signal of S1 (turquoise); the current through the inductor (red). (b) A clock frequency of 1 MHz. From top to bottom: the current through the load (dark violet); the control signal of S2 (black); the control signal of S1 (turquoise); the current through the inductor (red).
Figure 15.
Combination of three LED drivers of type II.
Figure 15.
Combination of three LED drivers of type II.
Figure 16.
With parasitic inductance of 0.2 µH, from top to bottom: voltage across S2 (dark green); voltage across S1 (turquoise); current through load (dark violet); current through coil (red); data (blue); control signal of S1 (green), without and with snubber in parallel to S2.
Figure 16.
With parasitic inductance of 0.2 µH, from top to bottom: voltage across S2 (dark green); voltage across S1 (turquoise); current through load (dark violet); current through coil (red); data (blue); control signal of S1 (green), without and with snubber in parallel to S2.
Figure 17.
LED driver and pulser of type III.
Figure 17.
LED driver and pulser of type III.
Figure 18.
The current through the coil measuring at 2 A. From top to bottom: the current through the load (dark violet); pulses (black); the control signal of the switch S1 (turquoise); the current through the coil (red).
Figure 18.
The current through the coil measuring at 2 A. From top to bottom: the current through the load (dark violet); pulses (black); the control signal of the switch S1 (turquoise); the current through the coil (red).
Figure 19.
A current through the coil measuring at 2 A. From top to bottom: the current through the load (dark violet); pulses (black); the control signal of the switch S1 (turquoise); the current through the coil (red).
Figure 19.
A current through the coil measuring at 2 A. From top to bottom: the current through the load (dark violet); pulses (black); the control signal of the switch S1 (turquoise); the current through the coil (red).
Figure 20.
Simulation circuit of hysteresis-controlled driving stage of type III.
Figure 20.
Simulation circuit of hysteresis-controlled driving stage of type III.
Figure 21.
Hysteresis-controlled driving stage of type III. From top to bottom: reference value (gray), input voltage (blue), and current through coil (red).
Figure 21.
Hysteresis-controlled driving stage of type III. From top to bottom: reference value (gray), input voltage (blue), and current through coil (red).
Figure 22.
Start-up of hysteresis-controlled driving stage of type III. From top to bottom: reference value (gray), input voltage (blue), and current through coil (red).
Figure 22.
Start-up of hysteresis-controlled driving stage of type III. From top to bottom: reference value (gray), input voltage (blue), and current through coil (red).
Figure 23.
Hysteresis-controlled driving stage of type III: (a) reference value step; (b) input voltage step. From top to bottom: reference value (gray), input voltage (blue), and current through coil (red).
Figure 23.
Hysteresis-controlled driving stage of type III: (a) reference value step; (b) input voltage step. From top to bottom: reference value (gray), input voltage (blue), and current through coil (red).
Figure 24.
Extended version of type III.
Figure 24.
Extended version of type III.
Figure 25.
Hysteresis-controlled driving stage of type III: influence of parasitic inductor at load side with 0.2 µH and 0.2 Ω. From top to bottom: current through L1 (red); voltage across load (turquoise); voltage across S2 (blue); input voltage (gray); voltage across S1 (green); input voltage (gray).
Figure 25.
Hysteresis-controlled driving stage of type III: influence of parasitic inductor at load side with 0.2 µH and 0.2 Ω. From top to bottom: current through L1 (red); voltage across load (turquoise); voltage across S2 (blue); input voltage (gray); voltage across S1 (green); input voltage (gray).
Figure 26.
Hysteresis-controlled driving stage of type III: influence of parasitic inductor at load side with 0.2 µH and 0.2 Ω and with RC snubber 10 Ω + 10 nF. From top to bottom: current through L1 (red); voltage across load (turquoise); voltage across S2 (blue); input voltage (gray); voltage across S1 (green); input voltage (gray).
Figure 26.
Hysteresis-controlled driving stage of type III: influence of parasitic inductor at load side with 0.2 µH and 0.2 Ω and with RC snubber 10 Ω + 10 nF. From top to bottom: current through L1 (red); voltage across load (turquoise); voltage across S2 (blue); input voltage (gray); voltage across S1 (green); input voltage (gray).
Figure 27.
Combination of three driving stages of type III.
Figure 27.
Combination of three driving stages of type III.
Figure 28.
The removal of the influence of the parasitic inductance at the input side. From top to bottom: the voltage across S1 (turquoise); the current through D1 (red); the voltage across S1 (blue); the control signal of S1 (black). The parasitic inductance is 1 µH and 470 nF is used as the input capacitor.
Figure 28.
The removal of the influence of the parasitic inductance at the input side. From top to bottom: the voltage across S1 (turquoise); the current through D1 (red); the voltage across S1 (blue); the control signal of S1 (black). The parasitic inductance is 1 µH and 470 nF is used as the input capacitor.
Figure 29.
Dimming, from top to bottom: current through LEDs (dark violet); current through L1 (red).
Figure 29.
Dimming, from top to bottom: current through LEDs (dark violet); current through L1 (red).