Buck controller for point-of-load regulation
The Texas Instruments LM2743MTCX/NOPB is a single-phase, step-down (buck) PWM controller designed for non-isolated DC-DC conversion. It drives an external N-channel MOSFET pair — one high-side, one low-side — in a synchronous rectifier topology, which improves efficiency at low output voltages compared to a diode-based freewheel. The controller operates from a 3V to 6V supply rail and switches between 50 kHz and 1 MHz, set by an external resistor on the frequency-control pin. Output voltage is regulated by the external divider; the part includes current limit, soft start, power-good flag, and tracking for sequencing multiple rails. The 14-TSSOP package suits compact point-of-load designs in industrial control, telecom, and base-station equipment where the -40°C to 125°C junction temperature range covers the thermal extremes of forced-air or enclosed environments.
Switching frequency and duty cycle — what they mean for the inductor and output cap
The 50 kHz to 1 MHz switching range lets the designer trade off inductor size against switching losses. The 80% maximum duty cycle limits the step-down ratio.
Synchronous rectification and control features
The synchronous rectifier driver for the low-side N-channel FET replaces the catch diode, cutting forward-drop loss and improving efficiency at high output current and low output voltage.
Active lifecycle — no LTB concern for new designs
The LM2743MTCX/NOPB carries an Active product status with ROHS3 compliance. This part is suitable for both new production and ongoing BOM maintenance. The NOPB suffix indicates lead-free (RoHS) finish, which matches current assembly requirements for most markets.