
19-2290; Rev 2; 3/04
ATION
AILABL
EVALU E
AV
KIT
1.5x/2x High-Efficiency White LED
Charge Pumps
General Description
The MAX1910/MAX1912 power LEDs with a regulated
output voltage or current (up to 120mA) from an unreg-
ulated input supply (2.7V to 5.3V). These are complete
DC-DC converters requiring only four small ceramic
capacitors and no inductors. Input ripple is minimized
by a unique regulation scheme that maintains a fixed
750kHz switching frequency over a wide load range.
Also included are logic-level shutdown and soft-start to
reduce input current surges at startup.
The MAX1910 has two automatically selected operating
modes: 1.5x and 2x. 1.5x mode improves efficiency at
higher input voltages, while 2x mode maintains regula-
tion at lower input voltages. The MAX1912 operates
only in 1.5x mode.
The MAX1910 and the MAX1912 are available in a
space-saving 10-pin μMAX package.
Applications
Features
? High-Efficiency 1.5x/2x Charge Pumps
? Low Input Ripple with 750kHz Operation
? 200mV Current-Sense Threshold Reduces
Power Loss
? Current- or Voltage-Regulated Charge Pump
? Up to 120mA Output Current
? No Inductors Required
? Small Ceramic Capacitors
? Regulated ±5% LED Current
? Load Disconnected in Shutdown
? 1 μ A Shutdown Current
? Small 10-Pin μ MAX Package
Ordering Information
White LED Backlighting
Cellular Phones
PDAs
PART
MAX1910 EUB
MAX1912 EUB
TEMP RANGE
-40 ° C to +85 ° C
-40 ° C to +85 ° C
PIN-PACKAGE
10 μMAX
10 μMAX
Digital Still Cameras
MP3 Players
Backup-Battery Boost Converters
Typical Operating Circuit
TOP VIEW
Pin Configuration
V IN
IN1
IN2
SHDN
OUT
GND 1
2
IN1
10 SET
9
C1-
C IN
C1
C2
C1+
C1-
C2+
MAX1910
MAX1912
SET
C OUT
C2-
C1+
OUT
3
4
5
MAX1910
MAX1912
8
7
6
IN2
C2+
SHDN
C2-
GND
μ MAX
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.
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