# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

National Semiconductor LP3961 LP3964 800mA Fast Ultra Low Dropout Linear Regulators Data Sheet User Manual

Summary

These fast, ultra low-dropout linear regulators are designed to provide high-efficiency, reliable DC power for demanding electronics like microprocessors and DSPs. Capable of delivering up to 800mA, they ensure stable voltage with minimal dropout. The included manual serves as a comprehensive technical guide, detailing operational parameters, available packages (SOT-223, TO-263), detailed connection diagrams, and application advice for engineers building robust low-voltage power supplies.

📄 Preview PAGE OF 21

Page 1 Text Content

查询LP3961供应商

LP 3961/LP 800m Fast ltra Low ropout Linear egulators

LP3961/LP3964 800m A Fast Ultra Low Dropout Linear Regulators General Description Features

The LP3961/LP3964 series of fast ultra low-dropout linear Ultra low dropout voltage

regulators operate from +2.5V to +7.0V input supply. Wide Low ground pin current range of preset output voltage options are available. These Load regulation of 0.02% ultra low dropout linear regulators respond very fast to step

15µA quiescent current in shutdown mode

changes in load which makes them suitable for low voltage

Guaranteed output current of 0.8A DC

microprocessor applications. The LP3961/LP3964 are de-

Available in SOT-223,TO-263 and TO-220 packages

veloped on CMOS process which allows low quiescent

Output voltage accuracy 1.5%

current operation independent of output load current. This

Error flag indicates output status (LP3961)

CMOS process also allows the LP3961/LP3964 to operate

under extremely low dropout conditions. Sense option improves better load regulation (LP3964) Extremely low output capacitor requirements

Dropout Voltage: Ultra low dropout voltage; typically 24m V

at 80m A load current and 240m V at 800m A load current. Overtemperature/overcurrent protection −40˚C to +125˚C junction temperature range

Ground Pin Current: Typically 4m A at 800m A load current. Shutdown Mode: Typically 15µA quiescent current when

Applications

the shutdown pin is pulled low.

Microprocessor power supplies

Error Flag: Error flag goes low when the output voltage

drops 10% below nominal value (for LP3961). GTL, GTL+, BTL, and SSTL bus terminators Power supplies for DSPs

SENSE: Sense pin improves regulation at remote loads.

(For LP3964) SCSI terminator Post regulators

Precision Output Voltage: Multiple output voltage options

are available ranging from 1.2V to 5.0V and adjustable, with High efficiency linear regulators

guaranteed accuracy of ±1.5% at room temperature, and Battery chargers

±3.0% over all conditions varying line, load, and tempera- Other battery powered applications ture).

Typical Application Circuits

DS101129-1

Minimum output capacitance is µF to ensure stability over full load current range. More capacitance provides superior dynamic performance and additional stability margin. *SD and ERROR pins must be pulled high through 10kΩ pull-up resistor. Connect the ERROR pin to ground if this function is not used. See applications sec- tion for more information.

National Semiconductor Corporation DS101129 www.national.com

Page Summary Contents For National Semiconductor LP3961 LP3964 800mA Fast Ultra Low Dropout Linear Regulators Data Sheet User Manual

Page 1 查询LP3961供应商 LP 3961/LP 800m Fast ltra Low ropout Linear egulators LP3961/LP3964 800m A Fast Ultra Low Dropout Linear Regulators General Description Features The LP3961/LP3964 series of fast ultra low-...
Page 2 Typical Application Circuits (Continued) LP /L DS101129-2 Minimum output capacitance is µF to ensure stability over full load current range. More capacitance provides superior dynamic performance and ...
Page 3 Block Diagram LP3964 LP 3961/LP DS101129-29 Block Diagram LP3964-ADJ DS101129-30 Connection Diagrams DS101129-4 SOT 223-5 Package www.national.com3
Page 4 Connection Diagrams (Continued) LP /L DS101129-5 TO220-5 Package Bent, Staggered Leads DS101129-6 TO263-5 Package Pin Description for SOT223-5 Package LP3961 LP3964 Name Function Name Function SD Shut...
Page 5 Ordering Information LP 3961/LP DS101129-31 Package Type Designator is ″MP″ for SOT223 package, ″T″ for TO220 package, and ″S″ for TO263 package. TABLE 1. Package Marking and Ordering Information Outp...
Page 6 Ordering Information (Continued) LP /L TABLE 1. Package Marking and Ordering Information (Continued) Output Order Number Description Package Package Marking Supplied As: Voltage (Current, Option) Type...
Page 7 Absolute Maximum Ratings (Note 1) IOUT (Survival) Short Circuit Protected LP 3961/LP Maximum Voltage for ERROR Pin VIN+0.3V If Military/Aerospace specified devices are required, please contact the Nat...
Page 8 Electrical Characteristics LP3961/LP3964 (Continued) LP /L Limits in standard typeface are for TJ 25˚C, and limits in boldface type apply over the full operating temperature range. Unless otherwise sp...
Page 9 Typical Performance Characteristics Unless otherwise specified, VIN =VO(NOM) 1V, VOUT= 2.5V, LP 3961/LP COUT =10µF, IOUT 10m A, CIN =10µF, VSD VIN, and TA 25˚C. Drop-Out Voltage Vs Temperature for Dif...
Page 10 Typical Performance Characteristics Unless otherwise specified, VIN =VO(NOM) 1V, VOUT= 2.5V, COUT =10µF, IOUT 10m A, CIN =10µF, VSD VIN, and TA 25˚C. (Continued) LP /L Ground Pin Current Vs Shutdown P...
Page 11 quency component and high frequency component, which Applications Information depend strongly on the silicon area and quiescent current. LP 3961/LP Noise can be reduced in two ways: by increasing the ...
Page 12 Applications Information (Continued) LP /L DS101129-7 FIGURE 1. Error Flag Operation Sense Pin tance. For example, in the case of 3.3V output, if the trace resistance is 100mΩ, the voltage at the remo...
Page 13 Applications Information pends on method of attachment, insulator, etc. θCH varies (Continued) between 1.5˚C/W to 2.5˚C/W. If the exact value is unknown, LP 3961/LP Dropout Voltage 2˚C/W can be assume...
Page 14 Applications Information (Continued) LP /L DS101129-19 FIGURE 5. θJA vs Copper(1 Ounce) Area for SOT-223 package The following figures show different layout scenarios for SOT-223 package. DS101129-22 ...
Page 15 Applications Information (Continued) LP 3961/LP DS101129-25 DS101129-24 FIGURE 11. SCENARIO F, θJA 75˚C/W FIGURE 10. SCENARIO E, θJA 77˚C/W DS101129-26 FIGURE 12. SCENARIO G, θJA 113˚C/W www.national....
Page 16 Applications Information (Continued) LP /L DS101129-27 FIGURE 13. SCENARIO H, θJA 79˚C/W www.national.com
Page 17 Applications Information (Continued) LP 3961/LP DS101129-28 FIGURE 14. SCENARIO I, θJA 78.5˚C/W www.national.com17
Page 18 Physical Dimensions inches (millimeters) unless otherwise noted LP /L TO220 5-lead, Molded, Stagger Bend Package (TO220-5) NS Package Number T05D For Order Numbers, refer to the “Ordering Information”...
Page 19 Physical Dimensions inches (millimeters) unless otherwise noted LP 3961/LP TO263 5-Lead, Molded, Surface Mount Package (TO263-5) NS Package Number TS5B For Order Numbers, refer to the “Ordering Inform...
Page 20 Physical Dimensions inches (millimeters) unless otherwise noted LP /L 0m Fa st ltr Lo ro po ut Li ne ar eg ul at or SOT223, 5-Lead, Molded, Surface Mount Package (SOT223-5) NS Package Number MA05C For...
Page 21 WWW.ALLDATASHEET.COM Copyright © Each Manufacturing Company. All Datasheets cannot be modified without permission. This datasheet has been download from : www.All Data Sheet.com 100% Free Data Sheet S...

Manual Details

Brand National
Pages 21
File Size 366.01 KB
Published June 16, 2026
11 views

Enter the captcha to get the download link:

captcha

Frequently Asked Questions

What is the minimum output capacitance required for stable operation?

A minimum of 10 μF is needed to ensure stability over the full load current range.

How does the Sense pin improve performance?

The sense pin improves better load regulation, especially under extremely low dropout conditions and at remote loads.

What must be done with the SD and ERROR pins if they are not in use?

The SD and ERROR pins must be pulled high through a 10kΩ pull-up resistor.

Is this regulator suitable for critical life support applications?

No, National’s products are not authorized for use as critical components in life support systems without express written approval.