Features Adjustable VOUT range of 0.80V to 1.8V Wide VBIAS Supply operating range of 3.0V to 5.5V Stable with 10µF Ceramic capacitors Dropout voltage of 115 mV (typical) at 800 mA load current Precision VADJ across all line and load conditions: ±1.5% VADJ for TJ = 25°C ±2.0% VADJ for 0°C ≤ TJ ≤ +125°C ±3.0% VADJ for -40°C ≤ TJ ≤ +125°C Over-Temperature and Over-Current protection Available in 8 lead PSOP, 7 lead TO-220 and 7 lead TO-263 packages −40°C to +125°C Operating Junction Temperature Range Description The LP38851-ADJ is a high current, fast response regulator which can maintain output voltage regulation with extremely low input to output voltage drop. Fabricated on a CMOS process, the device operates from two input voltages: VBIAS provides voltage to drive the gate of the N-MOS power transistor, while VIN is the input voltage which supplies power to the load. The use of an external bias rail allows the part to operate from ultra low VIN voltages. Unlike bipolar regulators, the CMOS architecture consumes extremely low quiescent current at any output load current. The use of an N-MOS power transistor results in wide bandwidth, yet minimum external capacitance is required to maintain loop stability. The fast transient response of this device makes it suitable for use in powering DSP, Microcontroller Core voltages and Switch Mode Power Supply post regulators. The part is available in PSOP 8–pin, TO-220 7–pin, and TO-263 7-pin packages. Dropout Voltage: 115 mV (typical) at 800 mA load current. Low Ground Pin Current: 10 mA (typical) at 800 mA load current. Soft-Start: Programmable Soft-Start time. Precision ADJ Voltage: ±1.5% for TJ = 25°C, and ±2.0% for 0°C ≤ TJ ≤ +125°C, across all line and load conditions Applications ASIC Power Supplies in: - Desktops, Notebooks, and Graphics Cards, Servers - Gaming Set Top Boxes, Printers and Copiers Server Core and I/O Supplies DSP and FPGA Power Supplies SMPS Post-Regulator

WEBENCH® LP38851     Min   Max   Range     VIN – V    1.00 – 5.50V     VOUT V    0.80 – 1.80V     IOUT A    ≤ 0.80A     Ambient Temp °C    ≤ 100°C   Footprint BOM Cost Efficiency What are WEBENCH® tools? Also Recommended LP38852▲ 1.5A Version LP38853▲ 3A Version LP38851-ADJ Typical Application Circuit

Typical Application *click for larger image LP38851-ADJ Typical Application Circuit	Block Diagram *click for larger image LP38851-ADJ Block Diagram
Typical Performance *click for larger image Ultra-Low Dropout Performance

Datasheets

Title		Size	Date	Other Language
	LP38851 800 mA Fast-Response High-Accuracy Adjustable LDO Linear Regulator with Enable and Soft-Start	463 Kbytes	13-Sep-11	日本語

Application Notes

Title		Size	Date	Other Language
	AN-1815: Application Note 1815 LDOs Ease the Stress of Start-Up	149 Kbytes	23-Sep-08

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LP38851MR-ADJ/NOPB RoHS Status	PSOP	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 10306 AVNET-EM Worldwide 1558 DIGI-KEY Worldwide 460 FARNELL Europe and Asia 194 NEWARK Americas 95 RS COMPONENTS Worldwide 15 TAYLOR Americas 10306	$0.75 each at 1K+ pcs	rail of 95
LP38851MRX-ADJ/NOPB RoHS Status	PSOP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.75 each at 1K+ pcs	reel of 2500
LP38851S-ADJ/NOPB LP38851S-ADJ RoHS Status	TO-263	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 129 AVNET-EM Worldwide 715 DIGI-KEY Worldwide 300 MOUSER Worldwide 315 TAYLOR Americas 129	$0.75 each at 1K+ pcs	rail of 45
LP38851SX-ADJ/NOPB LP38851SX-ADJ RoHS Status	TO-263	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 2000 DIGI-KEY Worldwide 0 TAYLOR Americas 2000	$0.75 each at 1K+ pcs	reel of 500
LP38851T-ADJ/NOPB LP38851T-ADJ RoHS Status	TO-220	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0 MOUSER Worldwide 315 RS COMPONENTS Worldwide 5	$0.75 each at 1K+ pcs	rail of 45

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LP38851.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LP38851 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LP38851MR-ADJ/NOPB	77.907	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L38851 MRADJ
LP38851MRX-ADJ/NOPB	77.907	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L38851 MRADJ
LP38851S-ADJ/NOPB LP38851S-ADJ	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LP38851S -ADJ
LP38851SX-ADJ/NOPB LP38851SX-ADJ	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LP38851S -ADJ
LP38851T-ADJ/NOPB LP38851T-ADJ	1846.782 1858.793	TO-220	7	1 1	NA NA	Detail	Download	N/A	NSUZXYTTE# LP38851T -ADJ

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LP38851.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LP38851 is located at RoHS Status.

Design Tools

Title	Size	Date
Article - How to Power Sub-Micron CMOS Loads with an Efficient LDO

CAD Symbols and Models Download LP38851 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LP38851MR-ADJ	CS065	2	47473	43	0	5527000	1	1568301341
LP38851MRX-ADJ	CS065	2	47473	43	0	5527000	1	1568301341
LP38851S-ADJ	CS065	2	47473	43	0	5527000	1	1568301341
LP38851SX-ADJ	CS065	2	47473	43	0	5527000	1	1568301341
LP38851T-ADJ	CS065	2	47473	43	0	5527000	1	1568301341

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.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LP38851.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LP38851 is located at RoHS Status.