LM22670 3A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Synchronization or Adjustable Switching Frequency

Part Number(s) (NSID)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM22670MR-5.0/NOPB	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L22670 5.0
LM22670MR-ADJ/NOPB	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L22670 ADJ
LM22670MRE-5.0/NOPB	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L22670 5.0
LM22670MRE-ADJ/NOPB	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L22670 ADJ
LM22670MRX-5.0/NOPB	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L22670 5.0
LM22670MRX-ADJ/NOPB	PSOP	8	3	260	Detail	Download	N/A	NSXYTT L22670 ADJ
LM22670TJ-5.0/NOPB	TO-263 THIN	7	1	260	Detail	Download	N/A	NSUZXYTTE# LM22670 TJ-5.0
LM22670TJ-ADJ/NOPB	TO-263 THIN	7	1	260	Detail	Download	N/A	NSUZXYTTE# LM22670 TJ-ADJ
LM22670TJE-5.0/NOPB	TO-263 THIN	7	1	260	Detail	Download	N/A	NSUZXYTTE# LM22670 TJ-5.0
LM22670TJE-ADJ/NOPB	TO-263 THIN	7	1	260	Detail	Download	N/A	NSUZXYTTE# LM22670 TJ-ADJ

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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.

The SIMPLE SWITCHER ® concept provides for an easy to use complete design using a minimum number of external components and National��s WEBENCH ® design tool. National��s WEBENCH ® tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in. The switching clock frequency is provided by an internal fixed frequency oscillator 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 shutdown, current limiting and an enable control input that can power down the regulator to a low 25 µA quiescent current standby condition.

Applications

•	Industrial Control
•	Telecom and Datacom Systems
•	Embedded Systems
•	Automotive Telematics and Body Electronics
•	Conversions from Standard 24V, 12V and 5V Input Rails

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)
•	��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
•	Fully WEBENCH ® enabled
•	Step-down and inverting buck-boost applications

Diagrams

Typical Application click for larger image

Connection Diagram *click for larger image

*click for larger image

Typical Performance click for larger image