National Semiconductor LM22670 User Guide and Technical Specifications
Summary
A high-efficiency, integrated 3A step-down voltage regulator built with advanced SIMPLE SWITCHER technology. This regulator accepts a wide input range of 4.5V to 42V and offers both fixed 5V and adjustable output options for simplified circuit design. The accompanying documentation provides full technical details on frequency synchronization, thermal management, and various package configurations. It is the ideal component for engineers developing robust embedded systems, telecommunication equipment, industrial control units, and automotive electronics.
Page 1 Text Content
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LM22670 3A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Synchronization or Adjustable Switching Frequency General Description Features The LM22670 series of regulators are monolithic integrated Wide input voltage range: 4.5V to 42V circuits which provide all of the active functions for a step-
Internally compensated voltage mode control
down (buck) switching regulator capable of driving up to 3A
Stable with low ESR ceramic capacitors
loads with excellent line and load regulation characteristics.
120 mΩ N-channel MOSFET TO-263 THIN package
High efficiency (>90%) is obtained through the use of a low
ON-resistance N-channel MOSFET. The series consists of a 100 mΩ N-channel MOSFET PSOP-8 package
fixed 5V output and an adjustable version. Output voltage options:
The SIMPLE SWITCHER® concept provides for an easy to -ADJ (outputs as low as 1.285V) use complete design using a minimum number of external -5.0 (output fixed to 5V)
components and National’s WEBENCH® design tool. ±1.5% feedback reference accuracy National’s WEBENCH® tool includes features such as exter-
Switching frequency of 500 k Hz, adjustable between 200
nal component calculation, electrical simulation, thermal sim-
k Hz and 1 MHz
ulation, and Build-It boards for easy design-in. The switching
-40°C to 125°C operating junction temperature range
clock frequency is provided by an internal fixed frequency os-
Precision enable pin
cillator which operates at 500 k Hz. The switching frequency
can also be adjusted with an external resistor or synchronized Integrated boot diode
to an external clock up to 1MHz. It is also possible to self- Integrated soft-start synchronize multiple regulators to share the same switching
Fully WEBENCH® enabled
frequency. The LM22670 series also has built in thermal shut-
Step-down and inverting buck-boost applications
down, current limiting and an enable control input that can power down the regulator to a low 25 µA quiescent current
Package
standby condition.
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
Simplified Application Schematic
© 2008 National Semiconductor Corporation www.national.com
Page Summary Contents For National Semiconductor LM22670 User Guide and Technical Specifications
Manual Details
| Brand | National |
|---|---|
| Pages | 18 |
| File Size | 480.35 KB |
| Published | June 17, 2026 |
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Frequently Asked Questions
What is the input voltage range for this regulator?
The LM22670 operates with a wide input voltage range of 4.5V to 42V.
Can the switching frequency be changed or synchronized?
Yes, the internal fixed frequency can be adjusted externally (up to 1MHz) or synchronized to multiple regulators using an external clock.
How do I use the WEBENCH tool for design?
The WEBENCH design tool facilitates all aspects of design-in, including component calculation, electrical simulation, and thermal simulation.
Does this regulator have features for protection?
It includes built-in thermal shutdown, current limiting, and an enable control input to power down the unit.