TPS54361/561 Step-Down DC-DC Converters

Texas Instruments' TPS54361 (2.5 A) and TPS54561 (5 A) are 60 V, step-down regulators with an integrated high-side MOSFET. The device survives load-dump pulses up to 65 V per ISO 7637. Current-mode control provides simple external compensation and flexible component selection. A low-ripple pulse-skip mode reduces the no-load supply current to 152 µA. Shutdown supply current is reduced to 2 µA when the enable pin is pulled low.

Undervoltage lockout is internally set at 4.3 V but can increase using an external resistor divider at the enable pin. The output voltage start-up ramp is controlled by the soft-start pin that can also be configured for sequencing/tracking. An open-drain power good signal indicates the output is within 93% to 106% of its nominal voltage.

A wide, adjustable switching-frequency range allows for optimization of either efficiency or external component size. Cycle-by-cycle current limit, frequency foldback, and thermal shutdown protect internal and external components during an overload condition.