Overview: ISL78235
5A Automotive Synchronous Buck Regulator
The ISL78235 is a highly efficient, monolithic, synchronous step-down DC/DC converter that can deliver 5A of continuous output current from a 2.7V to 5.5V input supply. The device uses peak current mode control architecture to achieve very low duty cycle operation at high frequency with fast transient response and excellent loop stability.
The ISL78235 integrates a low ON-resistance P-channel (35mΩ, typical) high-side FET and N-channel (11mΩ, typical) low-side FET to maximize efficiency and minimize external ponent count. The 100% duty cycle operation allows less than 250mV dropout voltage at 5A output current. The operating frequency of the Pulse-Width Modulator (PWM) is adjustable from 500kHz to 4MHz. The default switching frequency of 2MHz is set by connecting the FS pin high.
The ISL78235 can be configured for discontinuous (PFM) or forced continuous (PWM) operation at light load. Forced continuous operation reduces noise and RF interference; discontinuous mode provides higher efficiency by reducing switching losses at light loads.
Fault protection is provided by internal hiccup mode current limiting during short-circuit and overcurrent conditions. The device also integrates output overvoltage and over-temperature protections. A power-good monitor indicates when the output is in regulation.
