MAX1910EUB Maxim Integrated Products, MAX1910EUB Datasheet - Page 6

• Manufacturer Part Number: MAX1910EUB
• Description: LED Drivers 1.5x/2x White LED
• Manufacturer: Maxim Integrated Products

Specifications of MAX1910EUB

• Number Of Segments: 4
• Operating Supply Voltage: 2.7 V to 5.3 V
• Maximum Supply Current: 2.5 mA
• Maximum Power Dissipation: 444 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: uMAX-10
• Minimum Operating Temperature: - 40 C

1.5x/2x High-Efficiency White LED
Charge Pumps
Figure 8 shows a circuit using a DAC to set the LED
intensity. Maximum intensity occurs when the output of
the DAC is zero. R
maximum load current:
Use this as a starting point to calculate R
the formula below. The total LED current, I
DAC output voltages is determined by:
Figure 9 uses a digital input for two-level dimming control.
The LEDs are brightest when a logic-low input (V
0) is applied, and dimmed with a logic-high input.
Figure 1. Functional Charge-Pump Switch Diagram (Switches Shown for 1.5x Charging Phase)
6
_______________________________________________________________________________________
MODE
1.5x
1.5x
2x
2x
I
Applications Information
Charging
Charging
L
Transfer
Transfer
GND
PHASE
IN
L
0 2
R
R
.
L
can be initially estimated from the
L
(REGULATING
SWITCH)
-
SW7
(
0.2/I
V
Adjusting LED Intensity
DAC
SW1
R
L(MAX)
L
SW1
-
OFF
OFF
ON
ON
0 2
. )
R
A
C1-
R
B
A
L
and R
, at different
SW2
OFF
OFF
OFF
ON
C1+
LOGIC
B
from
=
SW6
SW3
OFF
ON
ON
ON
The total LED current is determined by:
The MAX1910/MAX1912 are high-frequency switched-
capacitor voltage regulators. For best circuit perfor-
mance, use a ground plane and keep C
C2, and feedback resistors (if used) close to the
device. If using external feedback, keep the feedback
node as small as possible by positioning the feedback
resistors very close to SET.
TRANSISTOR COUNT: 2497
PROCESS: BiCMOS
SW5
SW4
OFF
ON
ON
ON
I
L
C2-
0 2
R
SW4
.
L
-
(
SW5
OFF
OFF
V
ON
ON
LOGIC
C2+
R
L
Chip Information
-
0 2
R
. )
A
SW2
SW3
PC Board Layout
SW6
OFF
OFF
ON
ON
R
B
IN
OUT
, C
OUT
SW7
OFF
OFF
ON
ON
, C1,