August 2007
LM26400Y
Dual 2A, 500kHz Wide Input Range Buck Regulator
General Description
Features
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.
Input voltage range of 3-20V
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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
DTV-LCD
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Set-Top Box
XDSL
Automotive
Computing Peripherals
Industrial Controls
Point of Load
Typical Application
20200252
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202002
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