LMR51450SDRRR

LMR51450SDRRR is the tape-and-reel WSON-12 ordering code for the Texas Instruments LMR51450 step-down converter, listed by TI as ACTIVE. The S code is the 5 A variant with PFM light-load operation and spread-spectrum frequency modulation, per the datasheet device comparison table - the FN code of the same family (LMR51450FNDRRR) is the forced-PWM variant without spread spectrum, and the two codes must not be confused. Its feedback reference sits between 0.792 V and 0.808 V (0.800 V typical), non-switching quiescent current is 25 µA typical for the PFM variant, the high-side switch current limit runs between 6.4 A and 9.6 A (8 A typical), and switching frequency is 450 kHz to 550 kHz (500 kHz typical). The selection point is standby efficiency with EMI control at 5 A class: PFM operation keeps light-load drain low in always-on equipment, and spread spectrum flattens the switching noise peaks that complicate emissions testing in industrial and automotive accessory designs. Selection advice: quote the full SDRRR code - an FNDRRR substitution changes light-load behaviour and the EMI signature even though the footprint and rating match. Parameters verified against the TI LMR51450 datasheet (device comparison table and electrical characteristics for the S variant).