Buck controller with synchronous rectification
The Texas Instruments LM2727MTCX/NOPB is a step-down (buck) PWM controller that drives external N-channel MOSFETs in a synchronous rectifier topology. The 50kHz to 2MHz switching range lets the designer trade inductor size against switching losses — lower frequency for higher efficiency in a larger footprint, or 2MHz to shrink the magnetics at the cost of FET gate-drive losses. Supply voltage is 4.5V to 5.5V, so it needs a regulated 5V rail — not a wide-input part. The 90% max duty cycle leaves headroom when the input dips toward the output target; below that the controller skips pulses.
Control features and protection
Built-in current limit, enable, frequency control, power-good flag, and soft start cover the usual protection and sequencing needs. The soft start prevents output overshoot on power-up; power-good signals the downstream load that the rail is within regulation.
14-TSSOP package and mounting
Housed in a 14-lead TSSOP (4.40mm body width), the part is surface-mount only. The fine-pitch leads demand a controlled soldering profile and careful PCB layout — the switching node and gate-drive traces need short, low-inductance paths to the external FETs. Supplied in Tape & Reel for production pick-and-place; Cut Tape quantities are available for prototyping.
ROHS3 compliant, so it ships into EU and other restricted-material markets without exemption paperwork.