LP2954AISX

Manufacturer Part NumberLP2954AISX
Description5V and Adjustable Micropower Low-Dropout Voltage Regulators
ManufacturerNational Semiconductor
LP2954AISX datasheet
 


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LP2954/LP2954A
5V and Adjustable Micropower Low-Dropout Voltage
Regulators
General Description
The LP2954 is a 5V micropower voltage regulator with very
low quiescent current (90 µA typical at 1 mA load) and very
low dropout voltage (typically 60 mV at light loads and
470 mV at 250 mA load current).
The quiescent current increases only slightly at dropout
(120 µA typical), which prolongs battery life.
The LP2954 with a fixed 5V output is available in the
three-lead TO-220 and TO-263 packages. The adjustable
LP2954 is provided in an 8-lead surface mount, small outline
package. The adjustable version also provides a resistor net-
work which can be pin strapped to set the output to 5V.
Reverse battery protection is provided.
The tight line and load regulation (0.04% typical), as well as
very low output temperature coefficient make the LP2954
well suited for use as a low-power voltage reference.
Output accuracy is guaranteed at both room temperature
and over the entire operating temperature range.
Package Outline and Ordering Information
TO-220 3–Lead Plastic Package
Front View
Order Number LP2954AIT or LP2954IT
See NS Package T03B
© 1999 National Semiconductor Corporation
DS011128
Features
n 5V output within 1.2% over temperature (A grade)
n Adjustable 1.23 to 29V output voltage available
(LP2954IM and LP2954AIM)
n Guaranteed 250 mA output current
n Extremely low quiescent current
n Low dropout voltage
n Reverse battery protection
n Extremely tight line and load regulation
n Very low temperature coefficient
n Current and thermal limiting
n Pin compatible with LM2940 and LM340 (5V version
only)
n Adjustable version adds error flag to warn of output drop
and a logic-controlled shutdown
Applications
n High-efficiency linear regulator
n Low dropout battery-powered regulator
SO-8 Small Outline Surface Mount
DS011128-2
Order Number LP2954AIM or LP2954IM
See NS Package M08A
June 1999
DS011128-33
Top View
www.national.com

LP2954AISX Summary of contents

  • Page 1

    ... Package Outline and Ordering Information TO-220 3–Lead Plastic Package Front View Order Number LP2954AIT or LP2954IT See NS Package T03B © 1999 National Semiconductor Corporation DS011128 Features n 5V output within 1.2% over temperature (A grade) n Adjustable 1.23 to 29V output voltage available (LP2954IM and LP2954AIM) ...

  • Page 2

    Package Outline and Ordering Information TO-263 3-Lead Plastic Surface-Mount Package Ordering Information Order Number LP2954AIT LP2954IT LP2954AIS LP2954IS LP2954AIM LP2954IM www.national.com (Continued) DS011128-9 Top View DS011128-10 Side View Order Number LP2954AIS or LP2954IS See NS Package TS3B Temp. Range Package ...

  • Page 3

    ... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Operating Junction Temperature Range LP2954AI/LP2954I Electrical Characteristics = 25˚C, bold typeface applies over the −40˚C to +125˚C temperature range. Limits Limits in standard typeface are for T J are guaranteed by production testing or correlation techniques using standard Statistical Quality Control (SQC) methods ...

  • Page 4

    Electrical Characteristics = 25˚C, bold typeface applies over the −40˚C to +125˚C temperature range. Limits Limits in standard typeface are for T J are guaranteed by production testing or correlation techniques using standard Statistical Quality Control (SQC) methods. Un- = ...

  • Page 5

    Electrical Characteristics TABLE 1. Typical Values of Case-to-Heatsink Thermal Resistance (˚C/W) (Data from AAVID Eng.) Silicone grease Dry interface Mica with grease Note 3: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total ...

  • Page 6

    Typical Performance Characteristics Ripple Rejection DS011128-18 Line Transient Response DS011128-21 Load Transient Response DS011128-24 Thermal Response DS011128-27 www.national.com (Continued) Ripple Rejection DS011128-19 Line Transient Response DS011128-22 Load Transient Response DS011128-25 Short-Circuit Output Current and Maximum Output Current 6 Ripple Rejection ...

  • Page 7

    Typical Performance Characteristics Maximum Power Dissipation (TO-263) (See (Note 2) ) Application Hints EXTERNAL CAPACITORS A 2.2 µF (or greater) capacitor is required between the out- put pin and the ground to assure stability (refer to Figure 1 ). Without ...

  • Page 8

    Application Hints (Continued) *See External Capacitors = (V P − Total FIGURE 1. Basic 5V Regulator Circuit The next parameter which must be calculated is the maxi- mum allowable temperature rise, ...

  • Page 9

    Application Hints (Continued shutdown mode, ERROR will go high if it has been pulled external supply. To avoid this invalid response, pull up to regulator output Exact value depends on dropout voltage. (See ...

  • Page 10

    Typical Applications (Continued) *Output voltage equals +V minus dropout voltage, which varies with output current. Current limits at 380 mA (typical). IN Schematic Diagram www.national.com 5V Current Limiter DS011128-7 10 DS011128-8 ...

  • Page 11

    Physical Dimensions inches (millimeters) unless otherwise noted Order Number LP2954AIT or LP2954IT TO-220 3-Lead Plastic Package NS Package T03B 11 www.national.com ...

  • Page 12

    Physical Dimensions inches (millimeters) unless otherwise noted (Continued) TO-263 3-Lead Plastic Surface Mount Package www.national.com Order Number LP2954AIS or LP2954IS NS Package TS3B 12 ...

  • Page 13

    ... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...