The LM26420 regulator is a monolithic, high frequency, dual
PWM step-down DC/DC converter in a 16 Pin LLP and a 20
Pin eTSSOP package. It provides all the active functions to
provide local DC/DC conversion with fast transient response
and accurate regulation in the smallest possible PCB area.
With a minimum of external components, the LM26420 is
easy to use. The ability to drive two 2.0A loads with an internal
75 mΩ PMOS top switch and an internal 50 mΩ NMOS bottom
switch using state-of-the-art 0.5 μm BiCMOS technology results
in the best power density available. The world-class
control circuitry allows on-times as low as 30ns, thus supporting
exceptionally high frequency conversion over the entire
3V to 5.5V input operating range down to the minimum
output voltage of 0.8V. Switching frequency is internally set
to 550 kHz or 2.2 MHz, allowing the use of extremely small
surface mount inductors and chip capacitors. Even though the
operating frequency is high, efficiencies up to 93% are easy
to achieve. External shutdown is included, featuring an ultralow
stand-by current. The LM26420 utilizes current-mode
control and internal compensation to provide high-performance
regulation over a wide range of operating conditions.
Additional features include internal soft-start circuitry to reduce
inrush current, pulse-by-pulse current limit, thermal
shutdown, power good indicators, precision enables, and output
over-voltage protection.