MP1531
Low Power, Triple Output Step-Up
Plus Charge Pump for TFT Bias
MP1531 Rev. 1.2 www.MonolithicPower.com 1
5/22/2006 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
The Future of Analog IC Technology
DESCRIPTION
The MP1531 is a triple output step-up converter
with charge-pumps to make a complete DC/DC
converter to power a TFT LCD panel from a
2.7V to 5.5V supply.
The MP1531 includes a 250KHz fixed frequency
step-up converter and a positive and negative
linear regulator. The linear regulators are
powered via charge-pumps driven by the step-up
converter switch node.
A single on/off control enables all 3 outputs.
The outputs are internally sequenced at
power-on for ease of use. An internal soft-start
prevents overloading the input source at
startup. Cycle-by-cycle current limit reduces
component stress.
The MP1531 is available in both a tiny 16-pin
QFN package (3mm x 3mm) and a 16-pin
TSSOP package.
EVALUATION BOARD REFERENCE
Board Number Dimensions
EV1531DQ-002A 2.3”X x 2.3”Y x 0.5”Z
FEATURES
• 2.7V to 5.5V Operating Input Range
• 500mA Switch Current Limit
• 3 Outputs in a Single Package
• Step-Up Converter up to 22V
• Positive 10mA Linear Regulator
• Negative 10mA Linear Regulator
• 250m Internal Power MOSFET Switch
• 95% Efficiency
• 1µA Shutdown Mode
• Fixed 250KHz Frequency
• Positive Regulator up to 38V
• Negative Regulator down to -20V
• Internal Power-On Sequencing
• Adjustable Soft-Start/Fault Timer
• Thermal Shutdown
• Cycle-By-Cycle Over Current Protection
• Under Voltage Lockout
• Ready Flag
• 16-Pin TSSOP and QFN (3mm x 3mm) Packages
APPLICATIONS
• TFT LCD Displays
• Portable DVD Players
• Tablet PCs
• Car Navigation Displays
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION
MP1531
SW
FB1
FB3
IN3
GH
CT IN
PGNDGND
REF
FB2
GL
EN
COMP
IN2
RDY
OFF ON
TO
SW
V
GL
-4V
V
IN
2.7V-4.2V
V
MAIN
5V
V
GH
12V
100
90
80
70
60
50
40
30
20
EFFICIENCY (%)
0 100 200 300 400 500 600
LOAD CURRENT (mA)
Efficiency vs
Load Current
V
IN
= 3.3V
V
MAIN
= 5V
V
IN
= 4.2V
