LM26400Y Dual 2A, 500kHz Wide Input Range Buck Regulator
February 2007
LM26400Y
Dual 2A, 500kHz Wide Input Range Buck Regulator
General Description
The LM26400Y is a monolithic, two-output fixed frequency
PWM step-down DC/DC regulator in a 16-pin LLP or thermally
enhanced ETSSOP package. With a minimum number of ex-
ternal components and internal loop compensation, the
LM26400Y is easy to use. The ability to drive 2A loads with
an internal 175mΩ NMOS switch using state-of-the-art 0.5µm
BiCMOS technology results in a high-power density design.
The world class control circuitry allows for an ON-time as low
as 40 ns, thus supporting high-frequency conversion over the
entire input range of 3V to 20V and down to an output voltage
of only 0.6V. The LM26400Y utilizes peak current-mode con-
trol and internal compensation to provide high-performance
regulation over a wide range of line and load conditions.
Switching frequency is internally set to 500kHz, optimal for a
broad range of applications in terms of size versus thermal
tradeoffs. Given a non-synchronous architecture, efficiencies
above 90% are easy to achieve. External shutdown is includ-
ed, enabling separate turn-on and turn-off of the two chan-
nels. Additional features include programmable soft-start
circuitry to reduce inrush current, pulse-by-pulse current limit
and frequency foldback, integrated bootstrap structure and
thermal shutdown.
Features
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Input voltage range of 3-20V
Dual 2A output
Output voltage down to 0.6V
Internal compensation
500kHz PWM frequency
Separate enable pins
Separate soft start pins
Frequency foldback protection
175mΩ NMOS switch
Integrated bootstrap diodes
Over-current protection
ETSSOP and LLP packages
Thermal shutdown
Applications
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DTV-LCD
Set-Top Box
XDSL
Automotive
Computing Peripherals
Industrial Controls
Point of Load
Typical Application
20200252
© 2007 National Semiconductor Corporation
202002
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