Features • Operating input voltage range: 6V to 95V • Integrated 100V, N-Channel buck switch • Internal start-up regulator • No loop compensation required • Ultra-Fast transient response • On time varies inversely with input voltage • Operating frequency remains constant with varying line voltage and load current • Adjustable output voltage from 2.5V • Highly efficient operation • Precision internal reference • Low bias current • Intelligent current limit • Thermal shutdown Description The LM5008A is a functional variant of the LM5008 COT Buck Switching Regulator. The functional differences of the LM5008A are: The minimum input operating voltage is 6 volts, the on-time equation is slightly different, and the requirement for a minimum load current is removed. The LM5008A Step Down Switching Regulator features all of the functions needed to implement a low cost, efficient, Buck bias regulator. This high voltage regulator contains an 100 V N-Channel Buck Switch. The device is easy to implement and is provided in the MSOP-8 and the thermally enhanced LLP-8 packages. The regulator is based on a control scheme using an ON time inversely proportional to VIN. This feature allows the operating frequency to remain relatively constant. The control scheme requires no loop compensation. An intelligent current limit is implemented with forced OFF time, which is inversely proportional to Vout. This scheme ensures short circuit control while providing minimum foldback. Other features include: Thermal Shutdown, VCC under-voltage lockout, Gate drive under-voltage lockout, Max Duty Cycle limiter, and a pre-charge switch.

Also Recommended LM5007▲ 500mA Output Current, 9-75V Input Range Step-down Switching Regulator LM5010A▲ 1A Ouput Current 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
	LM5008A 100V, 350 mA Constant On-Time Buck Switching Regulator	391 Kbytes	28-Jun-09

Featured Application Notes

Title		Size	Date	Other Language
	AN-1925: Application Note 1925 LM5008A Evaluation Board	444 Kbytes	2-Jun-09

More Application Notes

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	AN-1937: Application Note 1937 LM3433 10A to 40A LED Driver Evaluation Board	1559 Kbytes	25-Mar-09
	AN-1875: Application Note 1875 LM5073HE Evaluation Board With Active Bridge	230 Kbytes	2-Jul-08
	AN-1319: Application Note 1319 Analysis and Design of a Hysteretic Constant Frequency Buck Regulator Using the LM5007	426 Kbytes	25-May-04	中文
	AN-1962: Application Note 1962 LM5032 Interleaved Boost Evaluation Board	2506 Kbytes	27-Aug-09
	AN-1820: Application Note 1820 LM5032 Interleaved Boost Converter	1942 Kbytes	30-May-08
	AN-1956: Application Note 1956 LM5001 Boost Evaluation Board	838 Kbytes	4-Mar-09
	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-1445: Application Note 1445 LM5009 Evaluation Board	479 Kbytes	23-Jul-08
	AN-1588: Application Note 1588 LM5001 Evaluation Board	658 Kbytes	18-Mar-07
	AN-1748: Application Note 1748 LM5005 Evaluation Board	159 Kbytes	7-Nov-07
	AN-1574: Application Note 1574 LM5073 Evaluation Board	464 Kbytes	24-Apr-07
	AN-1634: Application Note 1634 Starting Up A Buck Regulator With a Voltage Present At V OUT	71 Kbytes	17-May-07	日本語 中文
	AN-1298: Application Note 1298 LM5007 Evaluation Board	313 Kbytes	29-Jan-04
	AN-1630: Application Note 1630 LM5001 Non-Isolated Flyback Evaluation Board	250 Kbytes	17-Jun-09
	AN-1736: Application Note 1736 LM3433 HB LED Driver Evaluation Kit	1011 Kbytes	4-Feb-08
	AN-1793: Application Note 1793 LM3433 4A to 20A LED Driver Evaluation Board	701 Kbytes	25-Aug-08	中文

Design Tools

Title	Size	Date
LM5008A Quick Start Calculator	358 Kbytes	16-Jun-2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM5008AMM	ABCD150XV2	0	3601	0	0	1155496	4	327875145
LM5008AMMX	ABCD150XV2	0	3601	0	0	1155496	4	327875145
LM5008ASD	ABCD150XV2	0	3601	0	0	1155496	4	327875145
LM5008ASDX	ABCD150XV2	0	3601	0	0	1155496	4	327875145

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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