MAX8901A MAXIM [Maxim Integrated Products], MAX8901A Datasheet - Page 5

• Manufacturer Part Number: MAX8901A
• Description: Highest Efficiency Supply for 2 to 6 Series WLEDs in a 2mm x 2mm TDFN Package
• Manufacturer: MAXIM [Maxim Integrated Products]

(Circuit of Figure 5, I
Series WLEDs in a 2mm x 2mm TDFN Package
I
SUPPLY
V
V
I
LEDs
V
OUT
V
OUT
95
90
85
80
75
70
I
ON
LX
LX
V
I
LED
2
_______________________________________________________________________________________
= 24.75mA, V
LED AND BOOST EFFICIENCY
STARTUP AND SHUTDOWN
SWITCHING WAVEFORMS
RESPONSE (MAX8901A)
6WLEDs,
INDUCTOR: TOKO A915AY-220M,
DIODE: CENTRAL SEMI CMDSH05-4
3
vs. INPUT VOLTAGE
INPUT VOLTAGE (V)
Highest Efficiency Supply for 2 to 6
10ms/div
1μs/div
4
IN
BOOST
= V
LED
ON
5
C2 = 0.1μF
MAX8901A/B toc11
MAX8901A/B toc9
= 3.6V, C1 = 1µF, C2 = 1µF, T
Typical Operating Characteristics (continued)
6
100mV/div
AC-COUPLED
100mA/div
50mV/div
AC-COUPLED
10V/div
0V
0mA
0V
0V
100mA/div
0mA
20mA/div
0mA
2V/div
10V/div
I
SUPPLY
V
I
V
I
LEDs
LEDs
800
700
600
500
400
300
200
100
OUT
V
V
V
OUT
LX
ON
IN
0
2
A
= +25°C, unless otherwise noted.)
STARTUP AND SHUTDOWN
PROTECTION RESPONSE
3
RESPONSE (MAX8901B)
INPUT OVERVOLTAGE
vs. SUPPLY VOLTAGE
MAX8901B
SUPPLY VOLTAGE (V)
IN CURRENT (I
4
20ms/div
10ms/div
MAX8901A
5.4V
5
IN
)
6.4V
MAX8901A/B toc10
MAX8901A/B toc12
6
7
20mA/div
0mA
20mA/div
0V
1V/div
(AC-COUPLED)
10V/div
0V
100mA/div
20mA/div
2V/div
0V
10V/div
0V
0mA
0mA
5