Texas Instruments LM3444 Buck-Boost Topology MR16 LED Bulb Reference Design LM3444MR16BBRB/NOPB LM3444MR16BBRB/NOPB Datenbogen
Produktcode
LM3444MR16BBRB/NOPB
LM3444-MR16-Boost Reference Design
NATIONAL SEMICONDUCTOR
Page 5 of 20
Halogen MR16
Summary: No flickering observed. There is a delay (1.12ms, 24
° angle) from when the supply voltage starts
ramping up from zero volts to when the electronic transformer starts to operate and the bulb turns on. This delay
shows up on the LED MR16s as well although the magnitude of delay does vary from bulb to bulb. No current
spikes observed out of the transformer.
shows up on the LED MR16s as well although the magnitude of delay does vary from bulb to bulb. No current
spikes observed out of the transformer.
The bench set-up diagram below was used in the evaluation of the halogen MR16 bulb. The following scope plots
show voltage and current waveforms designated by the labels indicated in the bench set-up diagram. The
electronic transformer used was the Lightech LET-75.
show voltage and current waveforms designated by the labels indicated in the bench set-up diagram. The
electronic transformer used was the Lightech LET-75.
VIN (Yellow), IIN (Magenta), IBULB (Green)
Transformer
(Electronic)
LINE
NEUTRAL
120VAC
Power
Supply
12V, 50W Halogen
MR16 Bulb
LINE
NEUTRAL
+12V
SGND
Bench Circuit
IBULB
VBULB
VIN
IIN