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LM78S40  Product Folder

Universal Switching Regulator Subsystem
Generic P/N 78S40
General
Description
Features Datasheet Package
& Models
Samples
& Pricing
Reliability
Metrics
Application
Notes

Parametric Table Parametric Table
Temperature Min (deg C) -55 
Temperature Max (deg C) 125 
Multiple Output Capability
On/Off Pin No 
Error Flag No 
InputMin Voltage (Volt) 2.50 
InputMax Voltage (Volt) 40 
Output Current (mA) 1500 
Output Voltage (Volt)
Adjustable Output Yes 
Output Range 1.245V min. 
Switching Frequency (Hz) 100000 
Adj Switch Frequency Yes 
Sync Pin No 
Efficiency (%)
Flyback Yes 
Inverting Yes 
Step-Up Yes 
Step-Down Yes 
RegType Switching Regulator 

Datasheet

TitleSize in KbytesDate
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LM78S40 Universal Switching Regulator Subsystem 289 Kbytes 1-May-98 View Online Download Receive via Email
LM78S40 Mil-Aero Datasheet MNLM78S40-X 15 Kbytes   View Online Download Receive via Email

If you have trouble printing or viewing PDF file(s), see Printing Problems.

Package Availability, Models, Samples & Pricing

Part NumberPackageStatusModelsSamples &
Electronic
Orders
Budgetary PricingStd
Pack
Size
Package
Marking
TypePinsMSL/Lead-Free AvailabilityLead
Time
QtySPICEIBISQty$US each
LM78S40CNMDIP16StatusFull productionN/AN/A 
Buy Now
1K+$0.80rail
of
25
NSUZXYYTT
LM78S40CN
3-6 weeks25000
LM78S40NMDIP16StatusFull productionN/AN/A 
Buy Now
1K+$0.90rail
of
25
NSUZXYYTT
LM78S40N
3-6 weeks25000
LM78S40C MDAUnpackaged DieFull productionN/AN/ASamples  tray
of
N/A
-
N/A0
5962-8876101EACERDIP16StatusFull productionN/AN/A 
Buy Now
50+$14.10rail
of
25
NSZSSXXYYA>
LM78S40J/883QL
5962-8876101EA
6 weeks0

Obsolete Parts

Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
LM78S40CJ
LM78S40CN
NATIONAL SEMICONDUCTOR
07/15/95
LM78S40J
LM78S40N
NATIONAL SEMICONDUCTOR
03/08/94

General Description

The LM78S40 is a monolithic regulator subsystem consisting of all the active building blocks necessary for switching regulator systems. The device consists of a temperature compensated voltage reference, a duty-cycle controllable oscillator with an active current limit circuit, an error amplifier, high current, high voltage output switch, a power diode and an uncommitted operational amplifier. The device can drive external NPN or PNP transistors when currents in excess of 1.5A or voltages in excess of 40V are required. The device can be used for step-down, step-up or inverting switching regulators as well as for series pass regulators. It features wide supply voltage range, low standby power dissipation, high efficiency and low drift. It is useful for any stand-alone, low part count switching system and works extremely well in battery operated systems.

Features

  • Step-up, step-down or inverting switching regulators
  • Output adjustable from 1.25V to 40V
  • Peak currents to 1.5A without external transistors
  • Operation from 2.5V to 40V input
  • Low standby current drain
  • 80 dB line and load regulation
  • High gain, high current, independent op amp
  • Pulse width modulation with no double pulsing

Reliability Metrics

Part Number Process Early Failure Rate - Rejects Sample Size (EFR) PPM * Rel. Rejects Device Hours Long Term Failure Rates (FITS) MTTF
LM78S40C MDASLM0350000015000003424108012
LM78S40CNSLM0350000015000003424108012
LM78S40J/883SLM0350000015000003424108012
LM78S40NSLM0350000015000003424108012

For more information on Reliablitity Metrics, please click here.


Application Notes

TitleSize in KbytesDate
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AN-1149: Application Note 1149 Layout Guidelines for Switching Power Supplies 113 Kbytes 26-Sep-02 View Online Download Receive via Email
AN-1246: Application Note 1246 Stresses in Wide Input DC-DC Converters 272 Kbytes 26-Sep-02 View Online Download Receive via Email
AN-556: Application Note 556 Introduction to Power Supplies 159 Kbytes 25-Sep-02 View Online Download Receive via Email
AN-711: Application Note 711 LM78S40 Switching Voltage Regulator Applications 490 Kbytes 3-Oct-02 View Online Download Receive via Email

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 15-Jan-2004]