Datasheet

MAX1574
180mA, 1x/2x, White LED Charge Pump
in 3mm x 3mm TDFN
4 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(Circuit of Figure 2, V
IN
= 3.6V, EN = IN, driving three white LEDs, T
A
= +25°C, unless otherwise noted.)
LED CURRENT MATCHING
vs. INPUT SUPPLY VOLTAGE
MAX1574 toc04
INPUT SUPPLY VOLTAGE (V)
LED CURRENT MATCHING (%)
5.14.73.9 4.33.53.1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
2.7 5.5
I
LED
= 8mA
LED CURRENT vs. TEMPERATURE
MAX1574 toc05
TEMPERATURE (°C)
LED CURRENT (mA)
6035-15 10
7.85
7.90
7.95
8.00
8.05
8.10
8.15
8.20
7.80
-40 85
LED CURRENT vs. R
SET
MAX1574 toc06
R
SET
(kΩ)
LED CURRENT (mA)
10010
10
10001
100
1
100% BRIGHTNESS
SETTING
OPERATING WAVEFORMS (1x)
MAX1574 toc07
V
IN
V
OUT
I
IN
20mV/div
AC-COUPLED
50mV/div
AC-COUPLED
0mA
50mA/div
400ns/div
OPERATING WAVEFORMS (2x)
MAX1574 toc08
V
IN
V
OUT
I
IN
20mV/div
AC-COUPLED
50mV/div
AC-COUPLED
0mA
400ns/div
50mA/div
STARTUP AND SHUTDOWN
MAX1574 toc09
I
IN
V
EN
V
OUT
100mA/div
0mA
0V
5V/div
2V/div
1ms/div