Features • Input voltage range 2.95V to 5.5V • Accurate current limit minimizes inductor size • 96% peak efficiency at 1.0 MHz switching frequency • Frequency synchronization output • 32 mΩ integrated FET switches • Starts up into pre-biased loads • Output voltage tracking • Peak current mode control • Adjustable output voltage down to 0.8V • Adjustable Soft-Start with external capacitor • Precision enable pin with hysteresis • Integrated OVP, UVLO, power good and thermal shutdown • eTSSOP-16 exposed pad package Description The LM20154 is a full featured 1 MHz synchronous buck regulator capable of delivering up to 4A of continuous output current. The current mode control loop can be compensated to be stable with virtually any type of output capacitor. For most cases, compensating the device only requires two external components, providing maximum flexibility and ease of use. The device is optimized to work over the input voltage range of 2.95V to 5.5V making it suited for a wide variety of low voltage systems. The device features internal over voltage protection (OVP) and over current protection (OCP) circuits for increased system reliability. A precision enable pin and integrated UVLO allows the turn on of the device to be tightly controlled and sequenced. Start-up inrush currents are limited by both an internally fixed and externally adjustable Soft-Start circuit. Fault detection and supply sequencing is possible with the integrated power good circuit. The LM20154 features an open drain SYNCOUT pin which provides an external clock that matches the switching frequency of the device but is shifted by 180 degrees. The LM20154 is designed to work well in multi-rail power supply architectures. The output voltage of the device can be configured to track a higher voltage rail using the SS/TRK pin. If the output of the LM20154 is pre-biased at startup it will not sink current to pull the output low until the internal soft-start ramp exceeds the voltage at the feedback pin. The LM20154 is offered in an exposed pad 16-pin eTSSOP package that can be soldered to the PCB, eliminating the need for bulky heatsinks. Applications • Simple to design, high efficiency point of load regulation from a 5V or 3.3V bus • High Performance DSPs, FPGAs, ASICs and microprocessors • Broadband, Networking and Optical Communications Infrastructure

LM20154   2.95 <= V in Lower  V   <= V in Upper  V   <= 5.50 V out 0.80 <=  V <= 4.00 I out    A <= 4.00 Ambient Temperature  °C <= 100 What are WEBENCH® tools? Also Recommended LM20123▲ 3A, 1.5 MHz Switching Frequency LM20124▲ 4A, 1 MHz Switching Frequency LM20125▲ 5A, 500 KHz Switching Frequency LM20133▲ 3A, Input Synchronization (500 KHz - 1.5 MHz) LM20134▲ 4A, Input Synchronization (500 KHz - 1.5 MHz) LM20143▲ 3A, Adjustable Frequency (500 KHz - 1.5 MHz) LM20144▲ 4A, Adjustable Frequency (500 KHz - 1.5 MHz) LM20145▲ 5A, Adjustable Frequency (250 KHz - 750 KHz) LM20242▲ 36V, 2A Adjustable Frequency (250 KHz - 750 KHz) MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

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

Datasheets

Title		Size	Date	Other Language
	LM20154 4A, 1MHz Synchronous Buck Regulator with SYNCOUT	730 Kbytes	16-Dec-08	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1690: Application Note 1690 LM20154 Evaluation Board	431 Kbytes	30-Oct-07	日本語
	AN-1745: Application Note 1745 Powering FPGAs Using LM201xx PowerWise® Synchronous Buck Regulators	117 Kbytes	29-Oct-07	日本語 中文

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM20154MH/NOPB RoHS Status	TSSOP EXP PAD	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 3135 AVNET-EM Worldwide 34 DIGIKEY Worldwide 249 FUTURE Worldwide 92 RS COMPONENTS Worldwide 56	$2.75 each at 1K+ pcs	rail of 92
LM20154MHE/NOPB RoHS Status	TSSOP EXP PAD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$2.75 each at 1K+ pcs	reel of 250
LM20154MHX/NOPB RoHS Status	TSSOP EXP PAD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$2.75 each at 1K+ pcs	reel of 2500

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

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

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

Part Number(s) (NSID)	Top View	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM20154MH/NOPB		TSSOP EXP PAD	16	1	260	Detail	Download	N/A	NSUZXYTT 20154 MH
LM20154MHE/NOPB		TSSOP EXP PAD	16	1	260	Detail	Download	N/A	NSUZXYTT 20154 MH
LM20154MHX/NOPB		TSSOP EXP PAD	16	1	260	Detail	Download	N/A	NSUZXYTT 20154 MH

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

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

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

Design Tools

Title	Size	Date
Current Mode Modeling - Reference Guide	1372 Kbytes	1-Aug-2007
Understanding and Applying Current-Mode Control Theory	427 Kbytes	8-Jan-2008
Download LM20154 Design Spreadsheet
Article - Reducing Buck Converter Input Capacitance through Multi-Phasing and Clock Synchronization
Article - Benefits of Multi-Phasing- Part Two
Article - Benefits of Multi-Phasing- Part One

CAD Symbols and Models Download LM20154 CAD Symbols

Models N/A

LM20154   2.95 <= V in Lower  V   <= V in Upper  V   <= 5.50 V out 0.80 <=  V <= 4.00 I out    A <= 4.00 Ambient Temperature  °C <= 100 What are WEBENCH® tools?

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM20154MH	CMOS7	0	18406	0	0	1089000	4	309006723
LM20154MHE	CMOS7	0	18406	0	0	1089000	4	309006723
LM20154MHX	CMOS7	0	18406	0	0	1089000	4	309006723

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/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

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