Active step-down controller from the D-CAP™ family
The TPS51218DSCT is a Texas Instruments single-phase step-down (buck) PWM controller built on the D-CAP™ architecture, which uses a constant-on-time topology for fast transient response with no external compensation. It drives an external pair of N-channel MOSFETs in a synchronous rectifier configuration, covering the 4.5 V to 6.5 V supply range typical of 5 V intermediate rails in point-of-load designs.
Supply range, temperature grade, and package fit
Control features include enable, frequency control, and power-good flag — the frequency control pin lets the designer adjust the switching frequency with a resistor to avoid beat-frequency noise in multi-rail systems.