IRS2540

The IRS254(0,1) is a time-delayed hysteretic buck controller. During normal operating conditions the output current is regulated via the IFB pin voltage, nominal value of 500 mV. This feedback is compared to an internal high precision band gap voltage reference. An on-board dV/dt filter has also been used to prevent erroneous transitioning.

Once the supply to the chip reaches VCCUV+, the LO output is held high and the HO output is low for a predetermined period of time. This initiates the charging of the bootstrap capacitor, establishing the VBS floating supply for the high-side output. Then the chip begins toggling HO and LO outputs as needed to regulate the current. The deadtime of approximately 140 ns between the LO and HO gate drive signals prevents "shoot-through" and reduce switching losses, particularly at higher frequencies.