Features • Input voltage range 2.95V to 5.5V • Accurate current limit minimizes inductor size • 97% peak efficiency • Adjustable switching frequency (250 kHz to 750 kHz) • 16mΩ and 20mΩ 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 LM20146 is a full featured adjustable frequency synchronous buck regulator capable of delivering up to 6A 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 suitable 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 are possible with the integrated power good circuit. The LM20146 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 LM20146 is pre-biased at startup it will not pull the ouput low. The frequency of this device can be adjusted from 250 kHz to 750 kHz by connecting an external resistor from the RT pin to ground. The LM20146 is offered in a 16-pin eTSSOP package with an exposed pad 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

LM20146   2.95 <= V in Lower  V   <= V in Upper  V   <= 5.50 V out 0.80 <=  V <= 4.00 I out    A <= 6.00 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) LM20136▲ 6A, 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) LM20154▲ 4A, SYNCOUT 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 Efficiency vs. Load Current (VIN = 5V)

Datasheet

Title		Size	Date	Other Language
	LM20146 6A, Adjustable Frequency Synchronous Buck Regulator	509 Kbytes	12-Feb-09

Featured Application Notes

Title		Size	Date	Other Language
	AN-1902: Application Note 1902 LM20146 Evaluation Board	1685 Kbytes	19-Jan-09

More Application Notes

Title		Size	Date	Other Language
	AN-1745: Application Note 1745 Powering FPGAs Using LM201xx PowerWise® Synchronous Buck Regulators	117 Kbytes	29-Oct-07	日本語 中文
	AN-1747: Application Note 1747 3A LM20k Reference Designs	227 Kbytes	9-Nov-07
	AN-1751: Application Note 1751 4A LM20k Reference Designs	206 Kbytes	9-Nov-07
	AN-1752: Application Note 1752 5A LM20k Reference Designs	174 Kbytes	13-Nov-07
	AN-1692: Application Note 1692 LM20144 Evaluation Board	414 Kbytes	30-Oct-07	日本語
	AN-1691: Application Note 1691 LM20143 Evaluation Board	526 Kbytes	30-Oct-07	日本語
	AN-1693: Application Note 1693 LM20145 Evaluation Board	417 Kbytes	30-Oct-07	日本語

Design Tools

Title	Size	Date
Download LM20146 Design Spreadsheet	1369 Kbytes	19-Feb-2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM20146MH	CMOS7	0	18406	0	0	1089000	4	309006723
LM20146MHE	CMOS7	0	18406	0	0	1089000	4	309006723
LM20146MHX	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.

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