MAX1910 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – 1.5x/2x High-Efficiency White LED Charge Pumps

19-2290; Rev 2; 3/04
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.
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
♦ 1µA Shutdown Current
♦ Small 10-Pin µMAX Package
Applications
White LED Backlighting
Cellular Phones
PDAs
Digital Still Cameras
MP3 Players
Backup-Battery Boost Converters
PART
MAX1910EUB
MAX1912EUB
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
10 µMAX
10 µMAX
Typical Operating Circuit
V_IN
IN1 ^IN2
SHDN
OUT
C1+
C1
C_IN
C1- _MAX1910
C_OUT
MAX1912
C2+
C2
SET
C2-
GND
Pin Configuration
TOP VIEW
GND 1
IN1 2
C2- 3
C1+ 4
OUT 5
MAX1910
MAX1912
µMAX
10 SET
9 C1-
8 IN2
7 C2+
6 SHDN
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