IC REG SWITCH BUCK 3A 5V TO263-7

LM22676TJE-5.0/NOPB

Manufacturer Part NumberLM22676TJE-5.0/NOPB
DescriptionIC REG SWITCH BUCK 3A 5V TO263-7
ManufacturerNational Semiconductor
SeriesSIMPLE SWITCHER®
TypeStep-Down (Buck)
LM22676TJE-5.0/NOPB datasheet
 


Specifications of LM22676TJE-5.0/NOPB

Internal Switch(s)YesSynchronous RectifierNo
Number Of Outputs1Voltage - Output5V
Current - Output3AFrequency - Switching500kHz
Voltage - Input4.5 ~ 42 VOperating Temperature-40°C ~ 125°C
Mounting TypeSurface MountPackage / CaseTO-263-7 Thin
Primary Input Voltage12VNo. Of Outputs1
Output Voltage5VOutput Current3A
No. Of Pins7Operating Temperature Range-40°C To +125°C
MslMSL 1 - UnlimitedFilter TerminalsSMD
Rohs CompliantYesFor Use With551600233-001 - WEBENCH BUILD IT LM2267X TO-263
Lead Free Status / RoHS StatusLead free / RoHS CompliantPower - Output-
Other namesLM22676TJE-5.0TR  
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3A SIMPLE SWITCHER®, Step-Down Voltage Regulator
with Precision Enable
General Description
The LM22676 series of regulators are monolithic integrated
circuits which provide all of the active functions for a step-
down (buck) switching regulator capable of driving up to 3A
loads with excellent line and load regulation characteristics.
High efficiency (>90%) is obtained through the use of a low
ON-resistance N-channel MOSFET. The series consists of a
fixed 5V output and an adjustable version.
The SIMPLE SWITCHER
®
concept provides for an easy to
use complete design using a minimum number of external
components and National’s WEBENCH
National’s WEBENCH
®
tool includes features such as exter-
nal component calculation, electrical simulation, thermal sim-
ulation, and Build-It boards for easy design-in. The switching
clock frequency is provided by an internal fixed frequency os-
cillator which operates at 500 kHz. The LM22676 series also
has built in thermal shutdown, current limiting and an enable
control input that can power down the regulator to a low 25
µA quiescent current standby condition.
Simplified Application Schematic
© 2010 National Semiconductor Corporation
LM22676/LM22676Q
Features
Wide input voltage range: 4.5V to 42V
Internally compensated voltage mode control
Stable with low ESR ceramic capacitors
120 mΩ N-channel MOSFET TO-263 THIN package
100 mΩ N-channel MOSFET PSOP-8 package
Output voltage options:
-ADJ (outputs as low as 1.285V)
-5.0 (output fixed to 5V)
®
design tool.
±1.5% feedback reference accuracy
Switching frequency of 500 kHz
-40°C to 125°C operating junction temperature range
Precision enable pin
Integrated boot diode
Integrated soft-start
Fully WEBENCH
Step-down and inverting buck-boost applications
LM22676Q is an Automotive Grade product that is AEC-
Q100 grade 1 qualified (-40°C to +125°C operating
junction temperature)
Package
PSOP-8 (Exposed Pad)
TO-263 THIN (Exposed Pad)
Applications
Industrial Control
Telecom and Datacom Systems
Embedded Systems
Automotive Telematics and Body Electronics
Conversions from Standard 24V, 12V and 5V Input Rails
300765
December 10, 2010
®
enabled
30076501
www.national.com

LM22676TJE-5.0/NOPB Summary of contents

  • Page 1

    ... The LM22676 series also has built in thermal shutdown, current limiting and an enable control input that can power down the regulator to a low 25 µA quiescent current standby condition. Simplified Application Schematic © 2010 National Semiconductor Corporation LM22676/LM22676Q Features ■ Wide input voltage range: 4.5V to 42V ■ ...

  • Page 2

    ... Output Order Number Voltage ADJ LM22676MR-ADJ ADJ LM22676MRE-ADJ ADJ LM22676MRX-ADJ ADJ LM22676QMR-ADJ ADJ LM22676QMRE-ADJ ADJ LM22676QMRX-ADJ ADJ LM22676TJE-ADJ TO-263 THIN Exposed Pad ADJ LM22676TJ-ADJ ADJ LM22676QTJE-ADJ ADJ LM22676QTJ-ADJ 5.0 LM22676MR-5.0 5.0 LM22676MRE-5.0 5.0 LM22676MRX-5.0 www.national.com 8-Lead Plastic PSOP-8 Package NS Package Number MRA08B ...

  • Page 3

    ... Voltage 5.0 LM22676QMR-5.0 PSOP-8 Exposed Pad 5.0 LM22676QMRE-5.0 5.0 LM22676QMRX-5.0 5.0 LM22676TJE-5.0 TO-263 THIN Exposed Pad 5.0 LM22676TJ-5.0 5.0 LM22676QTJE-5.0 5.0 LM22676QTJ-5.0 *Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature grades defined in the AEC-Q100 standard. Automotive grade products are identified with the letter Q ...

  • Page 4

    Pin Descriptions Pin Numbers Pin Numbers PSOP-8 TO-263 THIN Package Package www.national.com Name Description Application Information BOOT Bootstrap input Provides the gate voltage for the ...

  • Page 5

    ... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN to GND EN Pin Voltage SW to GND (Note 2) BOOT Pin Voltage FB Pin Voltage Power Dissipation Electrical Characteristics junction temperature (T ) range of -40°C to +125°C. Minimum and Maximum limits are guaranteed through test, design, or statistical J correlation ...

  • Page 6

    Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond ...

  • Page 7

    Feedback Bias Current vs Temperature Standby Quiescent Current vs Input Voltage Normalized Feedback Voltage vs Input Voltage Normalized Enable Threshold Voltage vs Temperature 30076505 Normalized Feedback Voltage vs Temperature 30076506 30076509 7 30076510 30076507 www.national.com ...

  • Page 8

    Typical Application Circuit and Block Diagram www.national.com FIGURE 1. 3. OUT 8 30076514 ...

  • Page 9

    Detailed Operating Description The LM22676 switching regulator features all of the functions necessary to implement an efficient high voltage buck regu- lator using a minimum of external components. This easy to use regulator integrates a 42V N-Channel switch with an ...

  • Page 10

    FIGURE 2. Output Current in Foldback vs. Nominal Duty Cycle The percentage of output current limit fold back is affected by duty cycle, inductance, and See Figure 2 for details. The current limit will only protect the inductor from a ...

  • Page 11

    Application Information EXTERNAL COMPONENTS The following design procedures can be used to design a non- synchronous buck converter with the LM22676. Inductor The inductor value ...

  • Page 12

    Where V = 1.285V typical for the -ADJ option and 5V for the FB -5.0 option FIGURE 3. Resistive Feedback Divider A maximum value of 10 kΩ is recommended for the sum of R1 and R2 to keep ...

  • Page 13

    Thermal Considerations The two highest power dissipating components are the re- circulating diode and the LM22676 regulator IC. The easiest method to determine the power dissipation within the LM22676 is to measure the total conversion losses (Pin – Pout) then ...

  • Page 14

    PCB Layout Example for TO-263 THIN Package www.national.com 14 30076525 ...

  • Page 15

    PCB Layout Example for PSOP-8 Package Schematic for Buck/Boost (Inverting) Application See AN-1888 for more information on the inverting (buck- boost) application generating a negative output voltage from a positive input voltage. 30076541 30076526 15 www.national.com ...

  • Page 16

    Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 7-Lead Plastic TO-263 THIN Package NS Package Number TJ7A 8-Lead PSOP Package NS Package Number MRA08B 16 ...

  • Page 17

    Notes 17 www.national.com ...

  • Page 18

    ... For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www ...