Monolithic 1Amp DC:DC Step-down RegulatorThe EL7551 is an integrated, synchronous step-downregulator with output voltage adjustable from 1.0V to 3.8V. Itis capable of delivering 1A continuous current at up to 95%efficiency. The EL7551 operates at a constant frequencypulse width modulation (PWM) mode, making externalsynchronization possible. Patented on-chip resistorlesscurrent sensing enables current mode control, whichprovides cycle-by-cycle current limiting, over-currentprotection, and excellent step load response. The EL7551 isavailable in a fused-lead 16-pin QSOP package. With properexternal components, the whole converter fits into a lessthan 0.4 in2 area. The minimal external components andsmall size make this EL7551 ideal for desktop and portableapplications.The EL7551 is specified for operation over the -40°C to+85°C temperature range.