LM22680

` Wide input voltage range: 4.5V to 42V
` Internally compensated voltage mode control
` Stable with low ESR ceramic capacitors
` 200 mΩ N-channel MOSFET
` Output voltage option: -ADJ (outputs as low as 1.285V)
` ±1.5% feedback reference accuracy
` Switching frequency of 500 kHz, adjustable between 200 kHz and 1 MHz
` -40 to 125 operating junction temperature range
` Precision enable pin
` Integrated boot diode
` Adjustable soft-start
` Fully WEBENCH® enabled
` Step-down and inverting buck-boost applications

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

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

V_IN to GND ..................................................................43V
EN Pin Voltage .................................................-0.5V to 6V
SS, RT/SYNC Pin Voltage.................................. -0.5V to 7V
SW to GND (Note 2) ..........................................-5V to VIN
BOOT Pin Voltage ...............................................VSW + 7V
FB Pin Voltage ..................................................-0.5V to 7V
Power Dissipation.................................. Internally Limited
Junction Temperature ...............................................150
Soldering Information
Infrared (5 sec.) ...................................................260
ESD Rating (Note 3)
Human Body Model...............................................±2 kV
Storage Temperature Range...................... -65 to +150

The LM22680 series of regulators are monolithic integrated circuits which provide all of the active functions for a stepdown (buck) switching regulator capable of driving up to 2A 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 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 selfsynchronize multiple regulators to share the same switching frequency. The LM22680 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. An adjustable soft-start feature is provided by selecting an appropriate external soft-start capacitor.