MP1521_R2.7W Datasheet, PDF (1/2 Pages) List of Unclassifed Manufacturers – High Efficiency White LED Driver

Monolithic Power Systems
MP1521
High Efficiency
White LED Driver
General Description
The MP1521 is a constant-current Boost
Regulator. This IC has three individual
current-sensing feedbacks, which are ideal for
driving multiple strings of series connected
LEDs. The OLS pin is designed for detecting
loose or open LED connections.
The IC uses a peak current, constant minimum
off-time architecture. The feedback pins
measure voltage across sense resistors in
series with the LED strings. When supplying a
bias current of 20mA, the voltage drop across
the sense resistor is only 0.4V to minimize
power loss. Either a DC voltage or a PWM
signal at the BRT/PWM input can control the
LED brightness.
The MP1521 has an on board power MOSFET
switch that is protected by current limit, open
load shutdown, thermal shutdown, and under
voltage lockout.
Ordering Information
Part Number ∗
MP1521EK
Package
MSOP10
Temperature
-20° to +85°C
MP1521EQ
QFN16 (3x3) -20° to +85°C
EV0005
MP1521EK Evaluation Board
EV0021
MP1521EQ Evaluation Board
∗ For Tape & Reel, add suffix –Z (i.e., MP1521EK–Z)
For Lead Free, add suffix –LF (i.e., MP1521EK–LF–Z)
Features
ƒ On Board Power MOSFET
ƒ Drive 9 White LEDs from 2.7V Input
ƒ Drive 15 White LEDs from 5V Input
ƒ Up to 90% Efficiency
ƒ Over 80mA Output Current Capacity
ƒ Open Load Shutdown
ƒ Low Current Sensing Feedback Voltage
ƒ Up to 3 String Current Sensing Feedback
ƒ Analog and Digital PWM Brightness Control
ƒ UVLO, Thermal Shutdown
ƒ Soft Start
ƒ Internal Current Limit
ƒ Available in Compact MSOP10 and
Tiny 3 mm x 3 mm QFN16 Package
ƒ Evaluation Boards Available
Applications
ƒ Handheld Computers, Cell phones, PDAs,
Digital and Video Cameras, Small LCD
Displays
ƒ Li Ion and NiMH Battery Applications
Typical Application Circuit (One String of Six (6) LEDs)
1 IN
L1
D1
SW 10
ON
MP1521
COUT
OFF
EN 2 EN
GND 9
3 REF
BRT/
PWM
4 BRT/PWM
OLS 8
FB1 7
White LEDs
5 FB3
FB2 6
VIN
CIN
GND
Efficiency vs LED current, 1 string of 6
Using Toko D62CB 47µH Inductor
100
90
V_IN = 5V
80
V_IN = 4V
70
V_IN = 3V
60
50
5 10 15 20 25
LED Current (mA)
MP1521 Rev 2.7 10/06/04
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