Features • LM3478Q is AEC-Q100 qualified and manufactured on an Automotive Grade Flow • 8-lead Mini-SO8 (MSOP-8) package • Internal push-pull driver with 1A peak current capability • Current limit and thermal shutdown • Frequency compensation optimized with a capacitor and a resistor • Internal softstart • Current Mode Operation • Undervoltage Lockout with hysteresis Description The LM3478 is a versatile Low-Side N-Channel MOSFET controller for switching regulators. It is suitable for use in topologies requiring a low side MOSFET, such as boost, flyback, SEPIC, etc. Moreover, the LM3478 can be operated at extremely high switching frequency in order to reduce the overall solution size. The switching frequency of the LM3478 can be adjusted to any value between 100kHz and 1MHz by using a single external resistor. Current mode control provides superior bandwidth and transient response, besides cycle-by-cycle current limiting. Output current can be programmed with a single external resistor. The LM3478 has built in features such as thermal shutdown, short-circuit protection, over voltage protection, etc. Power saving shutdown mode reduces the total supply current to 5µA and allows power supply sequencing. Internal soft-start limits the inrush current at start-up. Key Specification • Wide supply voltage range of 2.97V to 40V • 100kHz to 1MHz Adjustable clock frequency • ±2.5% (over temperature) internal reference • 10µA shutdown current (over temperature) Applications • Distributed Power Systems • Battery Chargers • Offline Power Supplies • Telecom Power Supplies • Automotive Power Systems

LM3478   2.97 <= V in Lower  V   <= V in Upper  V   <= 40.00 V out 1.26 <=  V <= 300.00 I out    A <= 10.00 Ambient Temperature  °C <= 100 What are WEBENCH® tools? Also Recommended LM3481▲ Enables Use Of Smaller Inductor LM3488▲ Offers Clock Sync Capability LM5020▲ 100V Input LM5022▲ 60V Input, 2MHz Switching Frequency 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
	LM3478/LM3478Q High Efficiency Low-Side N-Channel Controller for Switching Regulator	495 Kbytes	30-Mar-09	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1286: Application Note 1286 Compensation For The LM3478 Boost Controller	204 Kbytes	19-May-09	日本語 中文
	AN-1204: Application Note 1204 LM3478/LM3488 Evaluation Board	218 Kbytes	10-May-04

More Application Notes

Title		Size	Date	Other Language
	AN-1149: Application Note 1149 Layout Guidelines for Switching Power Supplies	248 Kbytes	1-May-04	日本語
	AN-1193: Application Note 1193 LM3477 Evaluation Board	248 Kbytes	10-May-04
	AN-1381: Application Note 1381 LM3475 Evaluation Board	457 Kbytes	4-May-05

Design Tools

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Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3478MM	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3478MMX	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3478QMM	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3478QMMX	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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