Features • Low component count and small solution size • Stable with ceramic and other low ESR capacitors • No loop compensation required • High efficiency at a light load by DCM operation • Pre-bias startup • Ultra-fast transient response • Programmable soft-start • Programmable switching frequency up to 1 MHz • Valley current limit • Thermal shutdown • Output over-voltage protection • Precision internal reference for an adjustable output voltage down to 0.6V Description The LM3103 Synchronously Rectified Buck Converter features all required functions to implement a highly efficient and cost effective buck regulator. It is capable of supplying 0.75A to loads with an output voltage as low as 0.6V. Dual N-Channel synchronous MOSFET switches allow a low component count, thus reducing complexity and minimizing board size. Different from most other COT regulators, the LM3103 does not rely on output capacitor ESR for stability, and is designed to work exceptionally well with ceramic and other very low ESR output capacitors. It requires no loop compensation, results in a fast load transient response and simple circuit implementation. The operating frequency remains nearly constant with line variations due to the inverse relationship between the input voltage and the on-time. The operating frequency can be externally programmed up to 1 MHz. Protection features include VCC under-voltage lock-out, output over-voltage protection, thermal shutdown, and gate drive under-voltage lock-out. The LM3103 is available in the thermally enhanced eTSSOP-16 package. Key Specification • Input voltage range 4.5V-42V • 0.75A output current • 0.6V, ±2% reference • Integrated dual N-Channel main and synchronous MOSFETs • Thermally enhanced eTSSOP-16 package

LM3103   4.50 <= V in Lower  V   <= V in Upper  V   <= 42.00 V out 0.60 <=  V <= 7.00 I out    A <= 0.75 Ambient Temperature  °C <= 100 What are WEBENCH® tools? Also Recommended LM20242▲ 36V, 2A PowerWise Step_Down Synchronous Switching Regulator LM3100▲ Synchronous 1MHz 1.5A LM3102▲ Synchronous 1MHz 2.5A MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance *click for larger image

Datasheet

Title		Size	Date	Other Language
	LM3103 SIMPLE SWITCHER® Synchronous 1MHz 0.75A Step-Down Voltage Regulator	352 Kbytes	22-Oct-07	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1678: Application Note 1678 LM3103 Demonstration Board Reference Design	217 Kbytes	2-Oct-07

More Application Notes

Title		Size	Date	Other Language
	AN-1646: Application Note 1646 LM3102 Demonstration Board Reference Design	216 Kbytes	2-Oct-07	中文
	AN-1481: Application Note 1481 Controlling Output Ripple and Achieving ESR Independence in Constant On-Time (COT) Regulator Designs	574 Kbytes	27-Sep-06	日本語 中文
	AN-1443: Application Note 1443 LM3100 Demonstration Board Reference Design	3704 Kbytes	11-Mar-07	中文

Design Tools

Title	Size	Date
Article - Emulated Ripple Technique Advances Hysteretic Switchmode Supplies
Article - Tip of the Week: How to best implement a synchronous buck converter
Article - Emulated ripple makes step-down conversion easy

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3103MH	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3103MHX	ABCD150	0	34175	0	0	4234000	1	1201409060

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.

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