The LM26400Y device is a monolithic, two-output fixed-frequency PWM step-down DC-DC
regulator, in a 16-pin WSON or thermally-enhanced HTSSOP package. With a minimum number of external
components and internal loop compensation, the LM26400Y is easy to use.
The ability to drive 2-A loads with an internal 175-mΩ NMOS switch using state-of-the-art
0.5-µm 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 3 V to 20 V and down to an output voltage of only 0.6 V. The LM26400Y utilizes peak
current-mode control and internal compensation to provide high-performance regulation over a wide
range of line and load conditions. Switching frequency is internally set to 500 kHz, optimal for a
broad range of applications in terms of size versus thermal tradeoffs.
Given a nonsynchronous architecture, efficiencies above 90% are easy to achieve. External
shutdown is included, enabling separate turnon and turnoff of the two channels. 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.