Derating option for 2 to 8 white leds, Typical operating characteristics – Rainbow Electronics MAX8596Z User Manual
Page 4
MAX8595Z/MAX8596Z
High-Efficiency, 32V Step-Up Converters
with T
A
Derating Option for 2 to 8 White LEDs
4
_______________________________________________________________________________________
Typical Operating Characteristics
(Circuit of Figure 1, V
IN
= 3.6V, I
LED
= 25mA, L = 22µH, C
IN
= 2.2µF, C
OUT
= 0.1µF, C
COMP
= 0.1µF, R
SENSE
= 13
Ω, 4 LEDs,
T
A
= +25°C, unless otherwise noted.)
EFFICIENCY
vs. INPUT VOLTAGE
MAX8595Z toc01
INPUT VOLTAGE (V)
EFFICIENCY (%)
5
4
3
55
60
65
70
75
80
85
90
95
100
50
2
6
3 LEDs
4 LEDs
6 LEDs
8 LEDs
EFFICIENCY
vs. LED CURRENT
MAX8595Z toc02
LED CURRENT (mA)
EFFICIENCY (%)
25
20
15
10
5
65
70
75
80
85
90
60
0
30
3 LEDs
6 LEDs
8 LEDs
LED CURRENT
vs. DIRECT-PWM DIMMING
MAX8595Z toc03
DUTY CYCLE (%)
LED CURRENT (mA)
80
60
40
20
5
10
15
20
25
30
0
0
100
LED CURRENT
vs. AMBIENT TEMPERATURE
MAX8595Z toc04
TEMPERATURE (
°C)
LED CURRENT (mA)
80
60
20
40
0
-20
10
12
14
16
18
20
22
24
26
8
-40
100
MAX8596,
I
LED
= 25mA AT T
A
= +25
°C
MAX8595,
I
LED
= 15mA
SWITCHING WAVEFORMS
MAX8595Z toc05
500ns/div
V
IN
20mV/div
AC-COUPLED
200mV/div
AC-COUPLED
100mA/div
10V/div
V
LX
V
OUT
I
L
SOFT-START AND SHUTDOWN RESPONSE
MAX8595Z toc06
20ms/div
V
CTRL
2V/div
0
0
0
0
40mA/div
10V/div
100mA/div
I
IN
I
LED
V
OUT