LM2770

www.DataSheet4U.com LM2770 High Efficiency Switched Capacitor Step-Down DC/DC Regulator with Sleep Mode December 2004 LM2770 High Efficiency Switched Capacitor Step-Down DC/DC Regulator with Sleep Mode General Description The LM2770 is a switched capacitor step-down regulator that is ideal for powering low-voltage applications in portable systems. The LM2770 can supply load currents up to 250mA and operates over an input voltage range of 2.7V to 5.5V. This makes the LM2770 a great choice for systems powered by 1-cell Li-Ion batteries and chargers. The output voltage of the LM2770 can be dynamically switched between two output levels with a logic input pin. Output voltage pairs currently available include 1.2V/1.5V and 1.2V/1.575V. Other pairs of voltage options can be developed upon request. LM2770 efficiency is superior to both fixed-gain switched capacitor buck regulators and low-dropout linear regulators (LDO’s). Multiple fractional gains maximize power efficiency over the entire input voltage and output current ranges. The LM2770 can also be switched into a low-power sleep mode when load currents are light (≤ 20mA). In sleep mode, the charge pump is off, and the output is driven with a low-noise, low-power linear regulator. Soft-start, short-circuit protection, current-limit protection, and thermal-shutdown protection are also included. The LM2770 is available in National’s small 10-pin Leadless Leadframe Package (LLP-10). Features n High Efficiency Multi-Gain Archite...