Now, Intersil's ISL78233 and ISL78234 sold by Digi-Key are high-efficiency, monolithic, synchronous step-down DC-DC converters. They can provide 3A (ISL78233), 4A (ISL78234) and 5A (ISL7835) Continuous output current. 2.7V to 5.5V input power.
These devices use a current-mode control architecture that enables extremely low duty cycle operation at high frequencies with fast transient response and excellent loop stability.
The ISL78233 and ISL78234 integrate very low on-resistance P-channel (35mohm) high-side FETs and N-channel (11mohm) low-side FETs to maximize efficiency and reduce external component count. 100% duty cycle operation allows a voltage drop of less than 200mV at 4A output current. The operating frequency of the pulse width modulator (PWM) can be adjusted from 500kHz to 4MHz. The default switching frequency can be set to 2MHz by connecting the FS pin to a high level.
ISL78233, ISL78234 and ISL78235 can be configured to operate discontinuously or forcibly continuously under light load. Forced continuous operation reduces noise and RF interference, while non-continuous mode provides higher efficiency by reducing switching losses at light loads.
