LM2705

Features:

·150mA, 0.7Ω, internal switch
·Uses small surface mount components
·Adjustable output voltage up to 20V
·2.2V to 7V input range
·Input undervoltage lockout
·0.01µA shutdown current
·Small 5-Lead SOT-23 package




Application

·LCD Bias Supplies
·White LED Back-Lighting
·Handheld Devices
·Digital Cameras
·Portable Applications




Specifications

VIN 7.5V
SW Voltage 21V
FB Voltage2V
SHDN Voltage 7.5V
Maximum Junction Temp. TJ 150
(Note 2)

Lead Temperature
(Soldering 10 sec.) 300
Vapor Phase
(60 sec.) 215
Infrared
(15 sec.) 220
ESD Ratings (Note 3)
Human Body Model 2kV
Machine Model (Note 4) 200V

Regulated LEDs	3
Total LED Current	40 mA
Boost Type	Inductive
Efficiency (peak)	80 %
Input Min Voltage	2.2 Volt
Input Max Voltage	7 Volt
OutputMax Voltage	20 Volt
Boost Voltage	Unregulated
LED Configuration	Series
Supply Current	0.235 mA
Switching Type	PFM
PWM BrightCtrl	Yes
Analog-V BrightCtrl	No
Ambient Light Compensation	No
RGB-LED	No
Temperature Min	-40 deg C
Temperature Max	85 deg C
RegType	Switching Regulator
PowerWise	No
View Using Catalog

Description

The LM2705 is a micropower step-up DC/DC in a small 5-lead SOT-23 package. A current limited, fixed off-time control scheme conserves operating current resulting in high efficiency over a wide range of load conditions. The 21V switch allows for output voltages as high as 20V. The low 400ns off-time permits the use of tiny, low profile inductors and capacitors to minimize footprint and cost in spaceconscious portable applications. The LM2705 is ideal for LCD panels requiring low current and high efficiency as well as white LED applications for cellular phone back-lighting.

The LM2705 can drive up to 3 white LEDs from a single Li-Ion battery. The low peak inductor current of the LM2705 makes it ideal for USB applications.

The LM2705 is a micropower step-up DC/DC in a small 5-lead SOT-23 package. A current limited, fixed off-time control scheme conserves operating current resulting in high efficiency over a wide range of load conditions. The 21V switch allows for output voltages as high as 20V. The low 400ns off-time permits the use of tiny, low profile inductors and capacitors to minimize footprint and cost in space-conscious portable applications. The LM2705 is ideal for LCD panels requiring low current and high efficiency as well as white LED applications for cellular phone back-lighting. The LM2705 can drive up to 3 white LEDs from a single Li-Ion battery. The low peak inductor current of the LM2705 makes it ideal for USB applications.

Reliability Metrics

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Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2705MF-ADJ	ABCD150	0	31520	0	0	3739000	1	1060951459
LM2705MFX-ADJ	ABCD150	0	31520	0	0	3739000	1	1060951459

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.

More Application Notes

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Title	Size in Kbytes	Date
AN-1277: Application Note 1277 LM2703/LM2704 Evaluation Board	26 Kbytes	6-Mar-03	Download
AN-1308: Application Note 1308 LM2700 Evaluation Board	32 Kbytes	5-Jan-04	Download
AN-1250: Application Note 1250 Inductive Based Switching Regulator Circuits Provide High Efficiency White LED Drives	81 Kbytes	26-Sep-02	Download
AN-1237: Application Note 1237 RSDS™ Flat Panel Display Design Guidelines Part 2	141 Kbytes	14-May-03	Download

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