Document
MP24943
3A, 55V, 100kHz Step-Down Converter with Programmable Output OVP Threshold
The Future of Analog IC Technology
DESCRIPTION
The MP24943 is a monolithic, step-down, switch-mode converter. It supplies 3A of continuous output current over a wide inputsupply range with excellent load and line regulation.
MP24943 achieves low EMI signature with wellcontrolled switching edges.
Fault
condition
protection
includes
programmable-output over-voltage protection,
cycle-by-cycle current limit, and thermal
shutdown.
MP24943 requires a minimal number of readilyavailable standard external components. It is available in SOIC8 and SOIC8E package.
FEATURES
Wide 4.5V to 55V Operating Input Range Programmable Output Over-Voltage
Protection Output Adjustable from 0.8V to 45V 0.15Ω Internal Power MOSFET Switch Stable with Low ESR Output Ceramic
Capacitors Fixed 100kHz Frequency Low EMI Signature Thermal Shutdown Cycle-by-Cycle Over-Current Protection Available in SOIC8 and SOIC8E Packages
APPLICATIONS
Automotive GPS Automotive Entertainment Power Supply for Linear Chargers
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
95 90 VIN=12V 85
80
VIN=24V
75
70
VIN=55V
65
60
55
50 0 0.5 1 1.5 2
2.5 3
MP24943 Rev. 1.0
www.MonolithicPower.com
1
9/13/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
MP24943 –3A, 55V, 100kHz STEP-DOWN CONVERTER
Part Number MP24943DS* MP24943DN**
ORDERING INFORMATION
Package SOIC8 SOIC8E
Top Marking MP24943 MP24943
Free Air Temperature (TA) -40°C to +85°C -40°C to +85°C
* For Tape & Reel, add suffix –Z (eg. MP24943DS–Z); For RoHS, compliant packaging, add suffix –LF (eg. MP24943DS–LF–Z).
* For Tape & Reel, add suffix –Z (eg. MP24943DN–Z); For RoHS, compliant packaging, add suffix –LF (eg. MP24943DN–LF–Z).
PACKAGE REFERENCE
TOP VIEW
TOP VIEW
VIN 1
8 SW
VIN 1
8 SW
GND 2
7 BST
GND 2
7 BST
EN 3
6 VO
EN 3
6 VO
FB 4
5 SS
FB 4
5 SS
EXPOSED PAD ON BACKSIDE CONNECT TO PIN 2
SOIC8
SIOC8E
ABSOLUTE MAXIMUM RATINGS (1)
Input Voltage VIN .......................................... 60V VSW ..................................... -0.3V to (VIN + 0.3V) VBST ................................................... VSW + 6.5V All Other Pins ...............................-0.3V to +6.5V Junction Temperature ...............................150°C Lead Temperature ....................................260°C Storage Temperature............... -65°C to +150°C Continuous Power Dissipation (TA = 25°C) (2) SOIC8 ...................................................... 1.38W SOIC8E...................................................... 2.5W
Recommended Operating Conditions (3)
Input Voltage VIN .............................. 4.5V to 55V Output Voltage VOUT.........................0.8V to 45V Maximum Junction Temp. (TJ) ..................125°C
Thermal Resistance (4) θJA θJC
SOIC8..................................... 90 ...... 45... °C/W SOIC8E .................................. 50 ...... 10... °C/W
Notes: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD (MAX) = (TJ (MAX)-TA)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB.
MP24943 Rev. 1.0
www.MonolithicPower.com
2
9/13/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
MP24943 –3A, 55V, 100kHz STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS
VIN = 12V, TA = 25°C, unless otherwise noted.
Parameters
Symbol Condition
Feedback Voltage
Feedback Bias Current Output Over-Voltage Reference Switch-On Resistance Switch Leakage
Current Limit
VFB IBIAS(FB) VOVREF RDS(ON)
4.5V VIN 55V VFB = 0.8V
VEN = 0V, VSW = 0V Duty Cycle=10%
Oscillator Frequency
Bootstrap Voltage
Minimum-On Time
SW-rising edge
SW-falling edge EN-Input Low Voltage EN-Input High Voltage EN-Input Bias Current Under-Voltage Lockout Threshold Rising Under-Voltage Lockout Threshold Hysteresis Supply Current (Shutdown) Supply Current (Quiescent)
Thermal Shutdown
fSW VBST - VSW
tON trise tfall
VFB = 0.6V
VEN=0-6V
VEN=0V VEN = 2V, VFB = 1V
Min 0.78 -100 0.88
5.5 70
50
Typ 0.80 10
0..