Ultra-Efficient Charge Pumps for
Six White/RGB LEDs in 3mm x 3mm Thin QFN
Typical Operating Characteristics (continued)
(V = 3.6V, V
IN
= V , circuit of Figure 1, T = +25°C, unless otherwise noted.)
IN A
EN_
1x MODE OPERATING WAVEFORMS
1.5x MODE OPERATING WAVEFORMS
(V = 4V)
LED CURRENT vs. TEMPERATURE
(V = 3V)
IN
IN
MAX8647/48 toc14
MAX8647/48 toc15
30
25
20
15
10
5
AC-COUPLED
100mV/div
AC-COUPLED
100mV/div
V
V
IN
IN
100mA/div
I
IN
100mA/div
I
IN
0A
0A
20mA/div
20mA/div
I
I
LED
LED
ALL LEDs ON
ALL LEDs ON
0A
0A
I
= 24mA
LED
I
= 24mA
LED
0
-40
-15
10
35
60
85
400ns/div
400ns/div
7/MAX648
TEMPERATURE (°C)
STARTUP AND SHUTDOWN
(MAX8648)
SINGLE-WIRE PULSE DIMMING
(MAX8648)
MAX8647/48 toc16
MAX8647/48 toc17
ENA = ENB = ENC
2V/div
V
5V/div
EN_
OPERATING IN 1x
MODE, ALL 6 LEDs
OPERATING
V
EN_
AC-COUPLED
20mV/div
V
I
IN
IN
200mA/div
0A
TOTAL I
LED5
20mA/div
0A
I
LED5
2V/div
0A
1ms/div
10ms/div
LINE-TRANSIENT RESPONSE
LINE-TRANSIENT RESPONSE WITH MODE
(V = 4.3V TO 3.8V TO 4.3V)
CHANGE (V = 3.8V TO 3.4V TO 3.8V)
IN
IN
MAX8647/48 toc18
MAX8647/48 toc19
4.3V
3.8V
3.8V
3.4V
V
I
IN
IN
V
IN
I
IN
200mA/div
0A
200mA/div
0mA
24mA
20mA/div
I
24mA
20mA/div
LED6
I
LED6
1ms/div
1ms/div
6
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
