EL7551

NOT RECOMMENDED FOR NEW DESIGNS SEE EL7531 OR EL7536 EL7551 Monolithic 1Amp DC:DC Step-down Regulator DATASHEET FN7291 Rev 1.00 March 21, 2006 The EL7551 is an integrated, synchronous step-down regulator with output voltage adjustable from 1.0V to 3.8V. It is capable of delivering 1A continuous current at up to 95% efficiency. The EL7551 operates at a constant frequency pulse width modulation (PWM) mode, making external synchronization possible. Patented on-chip resistorless current sensing enables current mode control, which provides cycle-by-cycle current limiting, over-current protection, and excellent step load response. The EL7551 is available in a fused-lead 16-pin QSOP package. With proper external components, the whole converter fits into a less than 0.4 in2 area. The minimal external components and small size make this EL7551 ideal for desktop and portable applications. The EL7551 is specified for operation over the -40°C to +85°C temperature range. Pinout EL7551 (16-PIN QSOP) TOP VIEW C3 C4 0.1µF 270pF R3 39 C1 10µF ceramic VIN (4.5V-5.5V) 1 SGND PGND 16 2 COSC VREF 15 3 VDD FB 14 4 PGND VDRV 13 5 PGND LX 12 6 VIN LX 11 7 VIN VHI 10 8 EN PGND 9 C5 0.1µF R2 R1 2.37k 1k L1 10µH C6 0.1µF C7 VO 47µF (3.3V,1A) Manufactured under U.S. Patent No. 57,323,974 Features Integrated synchronous MOSFETs and current mode controller 1A continuous output current Up to 95% efficiency 4.5V to 5.5V input voltage Adjustable output from 1V to 3.8V C...