TPS56921

The TPS56921 in thermally enhanced 20-pin HTSSOP package is a full featured 17V, 9A synchronous step down converter which is optimized for small designs through high efficiency and integrating the high-side and low-side MOSFETs. After the initial power-up, the output voltage can be changed by codes sent to the IC via an I²C compatible VID Control bus. Current mode control provides space savings and easy compensation.

The output voltage startup ramp is controlled by the SS pin which helps to control startup inrush current. Power sequencing is supported by configuring the enable and the open drain power good pins. The output voltage is user-configurable at startup by external voltage divider.

Cycle by cycle current limiting on the high-side fet protects the TPS56921 in overload situations and is enhanced by a low-side sourcing current limit which prevents current runaway. There is also a low-side sinking current limit which turns off the low-side MOSFET to prevent excessive reverse current. Hiccup protection will be triggered if the overcurrent condition has persisted for longer than the preset time. Thermal hiccup protection disables the part when die temperature exceeds thermal shutdown temperature and enables the part again after the built-in thermal hiccup time.