MP28259
High Efficiency, Fast Transient, 2A,
4.2V-20V Input Synchronous
Step-down Converter in QFN12 (2x3mm)
The Future of Analog IC Technology
DESCRIPTION FEATURES
The MP28259 is a fully-integrated synchronous,
Wide 4.2V to 20V Operating Input Range
rectified, step-down switch mode converter with
2A Output Current
programmable frequency. It offers a very
(ON) Internal Power MOSFETs
Low R
DS
compact solution that can achieve a 2A
Proprietary Switching Loss Reduction
continuous output current over a wide input
Technique
supply range with excellent load and line
Power-Good Indicator in QFN Package
regulation, and can operate at high efficiency
Soft Shutdown
over a wide output current load range.
Programmable Switching Frequency
Constant-On-Time (COT) control mode OCP, SCP, OVP, UVP Protection and
provides fast transient response and eases loop Thermal Shutdown
stabilization.
Optional OCP Protection: Latch-Off Mode
and Hiccup Mode
Full protection features include SCP, OCP, OVP,
Output Adjustable from 0.815V to 13V
UVP, and thermal shut down.
Available in a QFN12 (2mmx3mm) Package
The MP28259 requires a minimal number of
APPLICATIONS
readily-available standard external components.
Networking Systems
The device is available in a space saving
Distributed Power Systems
2mmx3mm 12-pin QFN package.
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Quality Assurance. MPS and The
Future of Analog IC Technology are Registered Trademarks of Monolithic
Power Systems, Inc.
TYPICAL APPLICATION
9 3
IN
BST
VIN
C3
4.2V - 20V
C1
R7
L1
MP28259
2, 10
VOUT
SW
1.2V
8
FREQ
4
VCC
C5 R1
R4 C4
220pF
C2
7
FB
5
EN
EN
OFF ON
6
R2
PG
GND
1, 11, 12
MP28259 Rev. 1.34 www.MonolithicPower.com 1
4/27/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
2012 MPS. All Rights Reserved. MP28259 2A, 4.2V-20V INPUT, FAST TRANSIENT SYNCHRONOUS STEP-DOWN CONVERTER
ORDERING INFORMATION
Part Number* OCP Protection Package Top Marking
MP28259DD Latch-off mode QFN12 (2x3mm) AAT
MP28259DD-A Hiccup mode QFN12 (2x3mm) ACX
* For Tape & Reel, add suffix Z (e.g. MP28259DDZ).
For RoHS Compliant Packaging, add suffix LF (e.g. MP28259DDLFZ)
PACKAGE REFERENCE
TOP VIEW
GND
12
GND 11 GND
1
10
SW SW
2
SW
BST 3 9 IN
4 8
VCC FREQ
5 7
EN FB
6
PG
QFN12 (2x3mm)
(4)
(1)
Thermal Resistance
JA JC
ABSOLUTE MAXIMUM RATINGS
QFN12 (2x3mm) .................... 70 ...... 15... C/W
Supply Voltage V .......................................22V
IN
V ...-0.3V(-4V<10ns) to V + 0.3V(24V<10ns)
SW IN
Notes:
1) Exceeding these ratings may damage the device.
V .................................................... V + 6V
BST SW
2) The maximum allowable power dissipation is a function of the
All Other Pins................................. -0.3V to +6V
maximum junction temperature T (MAX), the junction-to-
J
(2)
ambient thermal resistance , and the ambient temperature
Continuous Power Dissipation (T = 25C) JA
A
T . The maximum allowable continuous power dissipation at
A
QFN12 (2x3mm)........................................1.8W
any ambient temperature is calculated by P (MAX) = (T
D J
Junction Temperature .............................150C (MAX)-T )/ . Exceeding the maximum allowable power
A JA
dissipation will cause excessive die temperature, and the
Lead Temperature ...................................260C
regulator will go into thermal shutdown. Internal thermal
Storage Temperature...............-65C to +150 C
shutdown circuitry protects the device from permanent
damage.
(3)
3) The device is not guaranteed to function outside of its
Recommended Operating Conditions
operating conditions.
Supply Voltage V .......................... 4.2V to 20V
IN
4) Measured on JESD51-7, 4-layer PCB.
Output Voltage V .................... 0.815V to 13V
OUT
Operating Junction Temp. (T ). -40C to +125C
J
MP28259 Rev. 1.34 www.MonolithicPower.com 2
4/27/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
2012 MPS. All Rights Reserved.