MAX1913 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – 60mA 1.5x High-Efficiency White LED Charge Pumps

19-2290; Rev 0; 1/02
60mA 1.5x High-Efficiency White LED
Charge Pumps
General Description
The MAX1912/MAX1913* power LEDs with a regulated
output voltage or current (up to 60mA) from an unregu-
lated 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 MAX1912 has a reduced feedback (SET) threshold
of 200mV for minimum loss when operating as a current
source. The MAX1913 has a 1.25V SET threshold for
best accuracy in voltage-feedback applications.
Connecting SET to IN on the MAX1913 selects a preset
5.0V output voltage. Contact factory for current-sense
thresholds other than 200mV or preset output voltages
other than 5.0V
Features
o High-Efficiency 1.5x Charge Pumps
o Low Input Ripple with 750kHz Operation
o 200mV Current-Sense Threshold Reduces
Power Loss
o Current- or Voltage-Regulated Charge Pump
o 60mA Output Current
o No Inductors Required
o Small Ceramic Capacitors
o Regulated ±3% Output Voltage
o Load Disconnected in Shutdown
o 1µA Shutdown Current
o Small 10-Pin µMAX Package
Applications
Backlight White LED Biasing
Cellular Phones
PDAs
Digital Still Cameras
MP3 Players
Backup-Battery Boost Converters
Typical Operating Circuit
Ordering Information
PART
MAX1912EUB
MAX1913EUB50*
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
10 µMAX
10 µMAX
*Future product—contact factory for availability.
Selector Guide
PART
MAX1912EUB
MODE V_SET
V_OUT
1.5x 200mV Adjustable Current
MAX1913EUB50* 1.5x 1.25V 5.0V or Adjustable
*Future product—contact factory for availability.
V_IN
IN1 ^IN2
SHDN
OUT
C1+
C1
C_IN
C1- _MAX1912
C_OUT
C2+
C2
C2-
SET
GND
Pin Configuration
TOP VIEW
GND 1
IN1 2
C2- 3
C1+ 4
OUT 5
MAX1912/
MAX1913
10 SET
9 C1-
8 IN2
7 C2+
6 SHDN
10-PIN µMAX
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