LX1994
TM
廬
High Efficiency LED Driver
P
RODUCTION
D
ATA
S
HEET
APPLICATION CIRCUITS
WWW .
Microsemi
.C
OM
33uH
V
IN
= 2.0 to 5.5V
UPS5819
LX1994
VIN
PWM
S/P
BRT
R4
2.94k
FB
C2
1uF
LS
GND
CMP
DRV
SRC
OVP
FDV303
R6
1M
R1
28.7k
AUTO
R2
226k
R7
30k
0.1uF
R5
15
VDD
SNK
R3
23.2k
VSS
SRC
C1
22uF
MAX
AUTO MODE RESPONSE
100% DUTY
LX1970
80% DUTY
LED
CURRENT
60% DUTY
40% DUTY
20% DUTY
0% DUTY
AMBIENT LIGHT
Figure 2
鈥揚(yáng)WM Dimming applied to S/P Input and Light Sensor (Dimming option 1)
Vcc
1M
-
110k
+
BSS123
V
IN
= 2.0 to 5.5V
33uH
UPS5819
LX1994
VIN
DRV
SRC
OVP
BRT
R4
2.94k
FB
C2
1uF
LS
GND
CMP
S/P
FDV303
R6
1M
PWM
R1
28.7k
AUTO
R2
226k
R7
30k
0.1uF
R5
15
VDD
SNK
R3
4.99k
VSS
SRC
C1
100uF
AUTO MODE RESPONSE
LX1970
A
PPLICATIONS
A
PPLICATIONS
MAX
100% DUTY
80% DUTY
60% DUTY
LED
CURRENT
40% DUTY
20% DUTY
0% DUTY
AMBIENT LIGHT
Figure 3
鈥揚(yáng)WM Dimming applied to S/P Input and Light Sensor (Dimming option 2)
Copyright
漏
2003
Rev. 1.0a, 2004-08-10
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8