LP38855

The LP38855 is a high-current, fast-response regulator which can maintain output voltage regulation with an extremely low input to output voltage drop. Fabricated on a CMOS process, the device operates from two input voltages: V_BIAS provides power for the internal bias and control circuits, as well as drive for the gate of the N-MOS power transistor, while V_IN supplies power to the load. The use of an external bias rail allows the part to operate from ultra low V_IN 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 LP38855 is available in TO-220 and TO-263 5-Lead packages.

Dropout Voltage: 130 mV (typical) at 1.5A load current.

Low Ground Pin Current: 14 mA (typical) at 1.5A load current.

Shutdown Current: 1 µA (typical) I_IN(GND) when EN pin is low.

Precision Output Voltage: ±1.0% for T_J = 25°C and ±2.0% for 0°C ≤ T_J ≤ +125°C, across all line and load conditions

Reliability Metrics

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Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LP38855S-0.8	CS065	2	34108	59	0	3862000	1	1095853045
LP38855S-1.2	CS065	2	34108	59	0	3862000	1	1095853045
LP38855SX-0.8	CS065	2	34108	59	0	3862000	1	1095853045
LP38855SX-1.2	CS065	2	34108	59	0	3862000	1	1095853045
LP38855T-0.8	CS065	2	34108	59	0	3862000	1	1095853045
LP38855T-1.2	CS065	2	34108	59	0	3862000	1	1095853045

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.

Design Tools

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Title	Size in Kbytes	Date
How to Power Sub-Micron CMOS Loads with an Efficient LDO			View

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More Application Notes

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Title	Size in Kbytes	Date
AN-1560: Application Note 1560 LP38852MR-ADJ Evaluation Board	280 Kbytes	17-Mar-07	Download
AN-1560 (Chinese): Application Note 1560 LP38852MR-ADJ Evaluation Board	397 Kbytes
AN-1479: Application Note 1479 LP38856S-1.2 Evaluation Board	468 Kbytes	3-Nov-06	Download
AN-1479 (Chinese): Application Note 1479 LP38856S-1.2 Evaluation Board	230 Kbytes
AN-1504: Application Note 1504 LP38853S-ADJ Evaluation Board	573 Kbytes	13-Mar-07	Download
AN-1504 (Chinese): Application Note 1504 LP38853S-ADJ Evaluation Board	285 Kbytes
AN-1480: Application Note 1480 LP38859S-1.2 Evaluation Board	522 Kbytes	3-Nov-06	Download
AN-1480 (Chinese): Application Note 1480 LP38859S-1.2 Evaluation Board	228 Kbytes
AN-1815: Application Note 1815 LDOs Ease the Stress of Start-Up	149 Kbytes	23-Sep-08	Download

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