The LT?1375/LT1376 are 500kHz monolithic buck mode
switching regulators. A 1.5A switch is included on the die
along with all the necessary oscillator, control and logic
circuitry. High switching frequency allows a considerable
reduction in the size of external components. The topology
is current mode for fast transient response and good loop
stability. Both fixed output voltage and adjustable parts are
available.
A special high speed bipolar process and new design
techniques achieve high efficiency at high switching frequency.
Efficiency is maintained over a wide output current
range by using the output to bias the circuitry and by
utilizing a supply boost capacitor to saturate the power
switch. A shutdown signal will reduce supply current to
20mA on both parts. The LT1375 can be externally synchronized
from 550kHz to 1MHz with logic level inputs.
The LT1375/LT1376 fit into standard 8-pin PDIP and SO
packages, as well as a fused lead 16-pin SO with much
lower thermal resistance. Full cycle-by-cycle short-circuit
protection and thermal shutdown are provided.
Standard surface mount external parts are used, including
the inductor and capacitors.