Manufacturer Part NumberLM22670TJE-5.0/NOPB
DescriptionIC REG SWITCH BUCK 3A 5V TO263-7
ManufacturerNational Semiconductor
TypeStep-Down (Buck)
LM22670TJE-5.0/NOPB datasheet

Specifications of LM22670TJE-5.0/NOPB

Internal Switch(s)YesSynchronous RectifierNo
Number Of Outputs1Voltage - Output5V
Current - Output3AFrequency - Switching200kHz ~ 1MHz
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-263LM22670INVEVAL - BOARD EVALUATION FOR LM22670INVLM22670EVAL - BOARD EVALUATION FOR LM22670
Lead Free Status / RoHS StatusLead free / RoHS CompliantPower - Output-
Other namesLM22670TJE-5.0TR  
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3A SIMPLE SWITCHER®, Step-Down Voltage Regulator
with Synchronization or Adjustable Switching Frequency
General Description
The LM22670 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.
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 switching frequency
can also be adjusted with an external resistor or synchronized
to an external clock up to 1MHz. It is also possible to self-
synchronize multiple regulators to share the same switching
frequency. The LM22670 series also has built in thermal shut-
down, 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
© 2011 National Semiconductor Corporation
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, adjustable between 200
kHz and 1 MHz
-40°C to 125°C operating junction temperature range
Precision enable pin
Integrated boot diode
Integrated soft-start
Step-down and inverting buck-boost applications
LM22670Q is an Automotive Grade product that is AEC-
Q100 grade 1 qualified (-40°C to +125°C operating
junction temperature)
PSOP-8 (Exposed Pad)
TO-263 THIN (Exposed Pad)
Industrial Control
Telecom and Datacom Systems
Embedded Systems
Automotive Telematics and Body Electronics
Conversions from Standard 24V, 12V and 5V Input Rails
January 24, 2011

LM22670TJE-5.0/NOPB Summary of contents

  • Page 1

    ... The LM22670 series also has built in thermal shut- down, 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 © 2011 National Semiconductor Corporation LM22670/LM22670Q Features ■ Wide input voltage range: 4.5V to 42V ■ ...

  • Page 2

    ... LM22670MR-ADJ PSOP-8 Exposed Pad ADJ LM22670MRE-ADJ ADJ LM22670MRX-ADJ ADJ LM22670QMR-ADJ ADJ LM22670QMRE-ADJ ADJ LM22670QMRX-ADJ ADJ LM22670TJE-ADJ TO-263 THIN Exposed ADJ LM22670TJ-ADJ ADJ LM22670QTJE-ADJ ADJ LM22670QTJ-ADJ www.national.com 8-Lead Plastic PSOP-8 Package NS Package Number MRA08B 7-Lead Plastic TO-263 THIN Package NS Package Number TJ7A ...

  • Page 3

    ... LM22670MRX-5.0 5.0 LM22670QMR-5.0 5.0 LM22670QMRE-5.0 5.0 LM22670QMRX-5.0 5.0 LM22670TJE-5.0 TO-263 THIN Exposed 5.0 LM22670TJ-5.0 5.0 LM22670QTJE-5.0 5.0 LM22670QTJ-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 Name Package Package 1 3 BOOT RT/ SYNC GND 7 2 VIN www.national.com Description Application ...

  • 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 RT/SYNC Pin Voltage SW to GND (Note 2) BOOT Pin Voltage FB Pin Voltage Power Dissipation Electrical Characteristics junction temperature (T ) range of -40° ...

  • 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 30076005 Normalized Feedback Voltage vs Temperature 30076006 Switching Frequency vs RT/SYNC Resistor 30076009 7 30076010 30076007 30076013 ...

  • Page 8

    Typical Application Circuit and Block Diagram www.national.com FIGURE 1. 3. 600 kHz OUT 8 30076014 ...

  • Page 9

    Detailed Operating Description The LM22670 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

    Current Limit When the power switch turns on, the slight capacitance load- ing of the Schottky diode, D1, causes a leading-edge current spike with an extended ringing period. This spike can cause the current limit comparator to trip prematurely. A ...

  • Page 11

    FIGURE 3. Switching Frequency vs RT/SYNC Resistor Self Synchronize It is also possible to self-synchronize multiple LM22670 reg- ulators to share the same switching frequency. This can be done by attaching the RT/SYNC pins together and putting a 1 kΩ ...

  • Page 12

    Application Information EXTERNAL COMPONENTS The following design procedures can be used to design a non- synchronous buck converter with the LM22670. Inductor The inductor value is determined based on the load current, ripple current, and the minimum and maximum input ...

  • Page 13

    FB pin. Other output voltages can use the -ADJ option with a resistor divider. The resistor values can be determined by the following equa- tions: -ADJ option: -5.0 option: Where V = 1.285V typical for the -ADJ ...

  • Page 14

    FIGURE 6. Current Flow in a Buck Application Thermal Considerations The two highest power dissipating components are the re- circulating diode and the LM22670 regulator IC. The easiest method to determine the power dissipation within the LM22670 is to measure ...

  • Page 15

    PCB Layout Example for TO-263 THIN Package 15 30076025 www.national.com ...

  • Page 16

    PCB Layout Example for PSOP-8 Package www.national.com 16 30076041 ...

  • Page 17

    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. 30076026 17 www.national.com ...

  • Page 18

    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 18 ...

  • Page 19

    Notes 19 www.national.com ...

  • Page 20

    ... 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 ...