The TPS65321A-Q1 device is a combination of a high-VIN DC-DC step-down
converter, referred to as the buck regulator, with an adjustable switch-mode frequency from 100-kHz
to 2.5-MHz, and a high-VIN 280-mA low-dropout (LDO) regulator. The input range is 3.6 V to 36 V for
the buck regulator, and 3 V to
36 V for the LDO regulator. The buck regulator has an
integrated high-side MOSFET with an
active-low, open-drain power-good output-pin (nRST). The LDO regulator features a low-input
supply current of 45-µA typical in no-load, also has an integrated MOSFET.
Low-voltage tracking feature enables TPS65321A-Q1 to track the input supply during
The buck regulator provides a flexible design to fit system needs. The external loop
compensation circuit allows for optimization of the converter response for the appropriate
operating conditions. A low-ripple pulse-skip mode reduces the no-load input-supply current to
maximum 140 µA.
The device has built-in protection features such as soft start, current-limit, thermal
sensing and shutdown due to excessive power dissipation. Furthermore, the device has an internal
undervoltage-lockout (UVLO) function that turns off the device when the supply voltage is too