The LT1507 is a 500kHz monolithic step-down mode switching regulator that performs the same functions as the LT1375 but is optimized for lower input voltage applications. It will work in the 4V to 15V input range, compared to the LT1375's 5.5V to 25V input range. A 1.5A switch is included on the mold, along with all necessary oscillator, control and logic circuits. The high switching frequency greatly reduces the size of the external components. This topology is a current mode with fast transient response and good loop stability. There is a fixed output voltage (3.3V) and adjustable parts.
Block diagram
A special high-speed bipolar process and new design techniques enable the regulator to achieve high efficiency at high switching frequencies. Efficiency is maintained over a wide output current range by maintaining the static supply current to 4mA and saturating the NPN supply switch with a power boost capacitor. The shutdown signal reduces the power supply current to 20µA. The LT1507 can externally synchronize logic level inputs from 570kHz to 1MHz.
The LT1507 fits standard 8-pin SO and PDIP packages. Through efficient design, temperature rise is kept at a minimum level. Provides full cycle cycle short circuit protection and thermal shutdown. Standard surface mount external components are used, including inductors and capacitors.
