CAT37 Datasheet, PDF (3/13 Pages) Catalyst Semiconductor – CMOS White LED Driver Boost Converter

CAT37
ABSOLUTE MAXIMUM RATINGS
V_IN , FB, SHDN Voltage ......................................... 8 V
SW Voltage .......................................................... 20 V
Junction Temperature ....................................... 125°C
Storage Temperature .......................... -65°C to 160°C
ESD Rating - Human Body Model .................... 2000V
Lead Soldering Temperature ............................ 300°C
RECOMMENDED OPERATING CONDITIONS
Parameter
Range
Unit
V_IN
2.5 to 7
V
Ambient Temperature Range
-40 to +85
°C
Inductor L1
6.8 ±20% typical
µH
Input Capacitor C1
1.0 ±20% typical
µF
Output Capacitor C2
1.0 ±20% typical
µF
I_LED with 1 to 4 LEDs in series
0 to 20
mA
ELECTRICAL SPECIFICATIONS
Over recommended operating conditions unless otherwise specified. TA = 25˚C, VIN = 3V and VSHDN = 3V.
Symbol Parameter
Conditions
Min
Typ
Max
Units
Input Voltage Range
2.5
7
V
IQ
Quiescent Current
ISD
Shutdown Current
VFB
FB Pin Voltage
IFB
FB Pin Leakage Current
Shutdown High Threshold
VFB = 0.2 V
0.5
0.7
mA
VSHDN = 0 V
0.05
1
µA
4 LEDs at 15 mA
85
95
105
mV
1
2
µA
0.85
V
Shutdown Low Threshold
0.25
V
ISHDN
fSW
DC
Shutdown Pin Current
Boost Converter Frequency
Maximum Switch
Duty Cycle
1
0.8
1.2
1.6
90
95
nA
MHz
%
ISWL
Switch Current Limit
400
550
780
mA
Switch Saturation Voltage
ISW = 300 mA
150
200
mV
Switch Leakage Current
Switch Off, VSW = 5 V
0.01
5
µA
Efficiency
Figure 1 with
83
%
specified components
3
Doc No. 5005, Rev. R