STEVAL-ILL008V1 STMicroelectronics, STEVAL-ILL008V1 Datasheet - Page 4
STEVAL-ILL008V1
Manufacturer Part Number
STEVAL-ILL008V1
Description
EVAL BOARD CREE LED FLASHLIGHT
Manufacturer
STMicroelectronics
Datasheets
1.L6920DC.pdf
(13 pages)
2.STEVAL-ILL008V1.pdf
(4 pages)
3.STEVAL-ILL008V1.pdf
(15 pages)
Specifications of STEVAL-ILL008V1
Mfg Application Notes
Low Voltage LED Driver AppNote
Design Resources
STEVAL-ILL008V1 Gerber Files STEVAL-ILL008V1 Schematic STEVAL-ILL008V1 Bill of Materials
Outputs And Type
1, Non-Isolated
Voltage - Output
3.5V
Features
1V Start up Input Voltage
Voltage - Input
1 ~ 5.5 V
Utilized Ic / Part
L6920
Product
Display Modules
Core Chip
L6920DA
Output Voltage
3.5V
Kit Contents
L6920D, L4971, L6902D Reference Board
Development Tool Type
Hardware - Eval/Demo Board
Tool / Board Applications
LED Flashlight
Mcu Supported Families
L6920DA
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Output / Channel
-
Lead Free Status / Rohs Status
Details
Other names
497-5516
AN1941 APPLICATION NOTE
Figure 4. Upper trace: inductor current; lower track: LED current
Figure 5. Upper trace: inductor current; lower track: LED current
from the waveforms, the inductor peak current is limited at 1A. the maximum load current is
defined by following relationship:
where
When the load is heavier than I
go to continuous mode. Fig. 6 and Fig. 7 show that the circuit loses the regulation, but the cir-
cuit is running at its maximum duty cycle.
Figure 6. Vin = 1V; upper trace: inductor current; lower trace: LED current
4/15
is the efficiency, I
I
load_lim
lim
=1A, and T
load_lim
=
------------ - I
Vout
Vin
, the regulation will be lost, and the inductor current will
offmin
lim
–
=1 s.
I
T
LED
I
L
off min
500mA/div
100mA/div
I
I
I
I
I
LED
LED
Vout Vin
---------------------------- -
LED
L
L
500mA/div
500mA/div
100mA/div
100mA/div
I
2 L
100mA/div
L
500mA/div
–