LM78S40CN/NOPB National Semiconductor, LM78S40CN/NOPB Datasheet

IC MULTI CONFIG ADJ 1.5A 16DIP

LM78S40CN/NOPB

Manufacturer Part Number
LM78S40CN/NOPB
Description
IC MULTI CONFIG ADJ 1.5A 16DIP
Manufacturer
National Semiconductor
Type
Step-Down (Buck), Step-Up (Boost), Invertingr
Datasheets

Specifications of LM78S40CN/NOPB

Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.25 ~ 40 V
Current - Output
1.5A
Frequency - Switching
100kHz
Voltage - Input
2.5 ~ 40 V
Operating Temperature
0°C ~ 70°C
Mounting Type
Through Hole
Package / Case
16-DIP (0.300", 7.62mm)
Power - Output
1.04W
Common Mode Rejection Ratio
76
Current, Input Bias
35 nA (Comparator), 30 nA (Operational Amplifier)
Current, Input Offset
5 nA
Current, Output
1.5 A
Current, Supply
2.3 mA
Package Type
DIP-16
Power Dissipation
1.04 W
Regulation, Line
0.04 mV/V
Regulation, Load
0.2 mV/mA
Regulator Type
Switching, Step-Up, Step-Down
Temperature, Operating, Range
-40 to +125 °C
Voltage, Input
2.5 to 40 V
Voltage, Offset
1.5 mV (Comparator), 4 mV (Operational Amplifier)
Voltage, Output
1.25 to 40 V
Voltage, Supply, Rejection Ratio
76 dB
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
*LM78S40CN
*LM78S40CN/NOPB
78S40
LM78S40CN
© 1998 National Semiconductor Corporation
LM78S40
Universal Switching Regulator Subsystem
General Description
The LM78S40 is a monolithic regulator subsystem consisting
of all the active building blocks necessary for switching regu-
lator systems. The device consists of a temperature com-
pensated voltage reference, a duty-cycle controllable oscilla-
tor 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 ex-
ternal 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.
Block and Connection Diagrams
DS010057
16-Lead DIP
Top View
Features
n Step-up, step-down or inverting switching regulators
n Output adjustable from 1.25V to 40V
n Peak currents to 1.5A without external transistors
n Operation from 2.5V to 40V input
n Low standby current drain
n 80 dB line and load regulation
n High gain, high current, independent op amp
n Pulse width modulation with no double pulsing
DS010057-1
DS010057-2
www.national.com
April 1998

Related parts for LM78S40CN/NOPB

LM78S40CN/NOPB Summary of contents

Page 1

... It is useful for any stand-alone, low part count switching system and works extremely well in battery operated systems. Block and Connection Diagrams © 1998 National Semiconductor Corporation DS010057 Features n Step-up, step-down or inverting switching regulators n Output adjustable from 1.25V to 40V n Peak currents to 1 ...

Page 2

Ordering Information Part Number NS Package LM78S40J/883 J16A Ceramic DIP LM78S40N N16E Molded DIP LM78S40CN N16E Molded DIP www.national.com Temperature Range −55˚C to +125˚C −40˚C to +125˚C 0˚C to +70˚C 2 ...

Page 3

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Storage Temperature Range Ceramic DIP Molded DIP Operating Temperature Range Extended (LM78S40J) Industrial (LM78S40N) Commercial (LM78S40CN) Lead Temperature Ceramic DIP (Soldering, 60 sec.) Molded DIP (Soldering, 10 sec ...

Page 4

LM78S40 Electrical Characteristics = Operating temperature range 5.0V Symbol Parameter OUTPUT SWITCH SECTION h Output Transistor Current FE Gain I Output Leakage Current L POWER DIODE V Forward Voltage Drop FD I Diode Leakage ...

Page 5

Typical Performance Characteristics C vs OFF Time T DS010057-6 Discharge Current vs Input Voltage DS010057-8 Design Formulas Characteristic Step-Down ( Max on off − Max ...

Page 6

Functional Description SWITCHING FREQUENCY CONTROL The LM78S40 is a variable frequency, variable duty cycle device. The initial switching frequency is set by the timing capacitor. (Oscillator frequency is set by a single external capacitor and may be varied over a ...

Page 7

Typical Applications (Continued) FIGURE 2. Typical Step-Up Regulator and = 25˚C) Operational Performance (T A Characteristic Condition = 50 mA Output Voltage I O Line Regulation 5.0V V 15V I Load Regulation 5 100 mA O ...

Page 8

Typical Applications (Continued) FIGURE 4. Pulse Width Modulated Step-Down Regulator (f www.national.com DS010057- kHz) OSC 8 ...

Page 9

Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Ceramic Dual-In-Line Package (J) 16-Lead Molded Dual-In-Line Package (N) Order Number LM78S40N or LM78S40CN Order Number LM78S40J/883 NS Package Number J16A NS Package Number N16A 9 www.national.com ...

Page 10

... National Semiconductor Asia Pacific Customer Fax: +49 (0) 1 80-530 85 86 Response Group Email: europe.support@nsc.com Tel: 65-2544466 Fax: 65-2504466 Tel: +49 (0) 1 80-532 78 32 Email: sea.support@nsc.com Tel: +49 (0) 1 80-534 16 80 National Semiconductor Japan Ltd. Tel: 81-3-5620-6175 Fax: 81-3-5620-6179 ...

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