Ultra-Efficient Charge Pumps for
Six White/RGB LEDs in 3mm x 3mm Thin QFN
7/MAX648
Typical Operating Characteristics (continued)
(V = 3.6V, V
IN
= V , circuit of Figure 1, T = +25°C, unless otherwise noted.)
IN A
EN_
EFFICIENCY vs. SUPPLY VOLTAGE
(DRIVING SIX LEDs)
EFFICIENCY vs. Li+ BATTERY VOLTAGE
(DRIVING SIX LEDs)
EFFICIENCY vs. Li+ BATTERY VOLTAGE
(DRIVING SIX LEDs)
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
100
90
80
70
60
50
40
16mA/LED
1.6mA/LED
20.8mA/LED
6.4mA/LED
6.4mA/LED
20.8mA/LED
LEDs HAVE MISMATCHED V
F
LEDs HAVE MISMATCHED V
F
LEDs HAVE MISMATCHED V
F
2.7
3.0
3.3
3.6
3.9
4.2
4.2 3.9
3.8
3.7
3.6
3.5 3.4 3.0
4.2 3.9
3.8
3.7
3.6
3.5 3.4 3.0
INPUT VOLTAGE (V)
Li+ BATTERY VOLTAGE (V, TIME-WEIGHTED)
Li+ BATTERY VOLTAGE (V, TIME-WEIGHTED)
INPUT CURRENT vs. INPUT VOLTAGE
(DRIVING SIX LEDs)
INPUT CURRENT vs. Li+ BATTERY
VOLTAGE (DRIVING SIX LEDs)
INPUT CURRENT
vs. INPUT VOLTAGE (RGB MODULE)
200
180
160
140
120
100
80
200
180
160
140
120
100
80
100
90
80
70
60
50
40
30
20
10
0
LEDs HAVE MISMATCHED V
RGB MODULE: LUMEX SML-LX3632SISUGSBC
F
I
= 20.8mA
LED
I
I
= 20.8mA
= 16mA
LED
LED
20.8mA/LED
16mA/LED
I
= 16mA
LED
LEDs HAVE MISMATCHED V
F
I
I
= 4.8mA
= 1.6mA
LED
LED
60
60
I
= 6.4mA
LED
6.4mA/LED
1.6mA/LED
40
40
20
20
I
= 1.6mA
3.7
LED
0
0
2.7
3.2
4.2
4.2 3.9
3.8
3.7
3.6
3.5 3.4 3.0
2.7
3.2
3.7
4.2
INPUT VOLTAGE (V)
Li+ BATTERY VOLTAGE (V, TIME-WEIGHTED)
INPUT VOLTAGE (V)
INPUT CURRENT vs. Li+ BATTERY
VOLTAGE (RGB MODULE)
INPUT RIPPLE VOLTAGE vs. SUPPLY
VOLTAGE (DRIVING SIX WHITE LEDs)
LED CURRENT MATCHING
vs. INPUT VOLTAGE (16mA/LED)
100
90
80
70
60
50
40
30
20
10
0
16
14
12
10
8
17.0
16.8
16.6
16.4
16.2
16.0
15.8
15.6
15.4
15.2
15.0
RGB MODULE: LUMEX SML-LX3632SISUGSBC
20.8mA/LED
20.8mA/LED
16mA/LED
16mA/LED
6.4mA/LED
LEDs HAVE
6
MISMATCHED V
F
6.4mA/LED
1.6mA/LED
4
2
1.6mA/LED
0
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
INPUT VOLTAGE (V)
4.2 3.9
3.8
3.7
3.6
3.5 3.4 3.0
2.7
3.2
3.7
4.2
Li+ BATTERY VOLTAGE (V, TIME-WEIGHTED)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
5
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
