LM2831,pdf datasheet (High Fre

The LM2831 regulator is a monolithic, high frequency, PWM
step-down DC/DC converter in a 5 pin SOT23 and a 6 Pin
LLP 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 LM2831 is easy to
use. The ability to drive 1.5A loads with an internal 130 mΩ
PMOS switch using state-of-the-art 0.5 μm BiCMOS technology
results in the best power density available. The worldclass
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 0.6V. Switching frequency is internally set
to 550 kHz, 1.6 MHz, or 3.0 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 ultra-low stand-by current of 30 nA.
The LM2831 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, and output
over-voltage protection.