LM5115 - Secondary Side Post Regulator / Synchronous Buck Controller
Datasheet Packaging Samples & Pricing Eval. Boards Reliability Application Notes Knowledge Base

Features
•Self-synchronization to main channel output
•Standalone DC/DC Synchronous buck mode
• Leading edge pulse width modulation
•Voltage-mode control with current injection and input line feed-forward
•Operates from AC or DC input up to 75V
• Wide 4.5V to 30V bias supply range
• Wide 0.75V to 13.5V output range.
•Top and bottom gate drivers sink 2.5A peak
• Adaptive gate driver dead-time control
• Wide bandwidth error amplifier (4MHz)
• Programmable soft-start
•Thermal shutdown protection
•TSSOP-16 or thermally enhanced LLP-16 packages

General Description

The LM5115 is a versatile switching regulator controller. More...


  Typical Application
click for larger image


ParametersValues
PWM Mode Voltage/current-injection
Topology Synchronous secondary-side post-regulator
Input Min Voltage 4.5 Volt
Input Max Voltage 75 Volt
Frequency Max 1000 kHz
Efficiency (peak) 90 %
Adj Switch Frequency Yes
Frequency Min 50 kHz
Sync Pin Yes
Sync Type Up
UVLO No
On/Off Pin Yes
Error Flag No
Current Limit Type cycle-cycle
Gate Drive 2.5 Amp
Output Current 20000 mA
Feedback Voltage 0.75 Volt
Feedback Tolerance 1.7 %
Output Range 0.75V to 13.5V
Special Features Operates from AC or DC input
Temperature Min -40 deg C
Temperature Max 125 deg C
Step-Down Yes
Step-Up No
Flyback No
Inverting No
RegType Switching Controller
Adjustable Output Yes
Output Power 300 Watt
Switching Frequency 1000 kHz
Multiple Output Capability No
Automotive Yes


Typical Performance

click for larger image


  Also Recommended
LM25115▲42V Maximum Input
LM25115A▲42V Maximum Input With Power-Up/Power-Down Tracking
LM5025▲Active Clamp Voltage Mode Pwm Controller
LM5025A▲Active Clamp Voltage Mode Pwm Controller
LM5115A▲With Power-Up/Power-Down Tracking
Additional Resources
Online Seminars Application Notes


Block Diagram

click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM5115 Secondary Side Post Regulator / Synchronous Buck Controller 756
Kbytes		 13-Jul-06 Download

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Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders		Budgetary PricingStd
Pack
Size		Package
Marking
Format
TypePinsSpec.MSL
Rating		Peak
Reflow		RoHS
Report		CAD
Symbols		WeeksQtyQty$US each
LM5115DC EVALSecondary Side Post Regulator / Synchronous Buck ControllerFull productionN/A
 
Buy Now 		1+$100.001-
8 weeksN/A
LM5115EVALSecondary Side Post Regulator / Synchronous Buck ControllerFull productionN/A
 
Buy Now 		1+$81.201-
8 weeksN/A
LM5115MTCTSSOP16NOPB
STD		1
1		260
260		RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.80rail
of
92		NSUZXYTT
LM5115
MTC
6 weeks2000
LM5115MTCXTSSOP16NOPB
STD		1
1		260
260		RoHS Download Full productionN/A
 
Buy Now 		1K+$1.80reel
of
2500		NSUZXYTT
LM5115
MTC
6 weeks3000
LM5115SDLLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.80reel
of
1000		NS
UZXYTT
5115SD
6 weeks3000
LM5115SDXLLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.80reel
of
4500		NS
UZXYTT
5115SD
6 weeksN/A

General Description

The LM5115 is a versatile switching regulator controller. It has two main application configurations. The first is utilizing the Secondary Side Post Regulation (SSPR) technique to implement multiple output power converters. In the second configuration, it can be used as a standalone synchronous buck controller (Please see page 14 for more details). The SSPR technique develops a highly efficient and well regulated auxiliary output from the secondary side switching waveform of an isolated power converter. Regulation of the auxiliary output voltage is achieved by leading edge pulse width modulation (PWM) of the main channel duty cycle. Leading edge modulation is compatible with either current mode or voltage mode control of the main output. The LM5115 drives external high side and low side NMOS power switches configured as a synchronous buck regulator. A current sense amplifier provides overload protection and operates over a wide common mode input range. Additional features include a low dropout (LDO) bias regulator, error amplifier, precision reference, adaptive dead time control of the gate signals and thermal shutdown.

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM5115MTCABCD150XV1038680025950002736338335
LM5115MTCXABCD150XV1038680025950002736338335
LM5115SDABCD150XV1038680025950002736338335
LM5115SDXABCD150XV1038680025950002736338335

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.


Application Notes

TitleSize in Kbytes Date Click link below to Download
AN-1368: Application Note 1368 LM5115/5025A Evaluation Board 1364
Kbytes		 5-Apr-05 Download
AN-1367: Application Note 1367 LM5115 HV DC Evaluation Board 943
Kbytes		 18-Oct-05 Download
AN-1367 (Chinese): Application Note 1367 LM5115 HV DC Evaluation Board
 614 Kbytes  
AN-1875: Application Note 1875 LM5073HE Evaluation Board With Active Bridge 230
Kbytes		 2-Jul-08 Download
AN-1574: Application Note 1574 LM5073 Evaluation Board 464
Kbytes		 24-Apr-07 Download

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More Application Notes

TitleSize in Kbytes Date Click link below to Download
AN-1542: Application Note 1542 LM5115A Evaluation Board 1789
Kbytes		 17-Mar-07 Download
AN-1542 (Chinese): Application Note 1542 LM5115A Evaluation Board
 669 Kbytes  
AN-1628: Application Note 1628 Minimizing FET Losses For a High Input Rail Buck Converter 91
Kbytes		 5-Sep-07 Download
AN-1628 (Japanese): Application Note 1628 Minimizing FET Losses For a High Input Rail Buck Converter
 115 Kbytes   Download
AN-1628 (Chinese): Application Note 1628 Minimizing FET Losses For a High Input Rail Buck Converter
 283 Kbytes  

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[Information as of 8-Nov-2009]