LM3355

LM3355 Regulated 50 mA Buck-Boost Switched Capacitor DC/DC Converter December 2001 LM3355 Regulated 50mA Buck-Boost Switched Capacitor DC/DC Converter General Description The LM3355 is a CMOS switched capacitor DC/DC converter that produces a regulated output voltage by automatically stepping up (boost) or stepping down (buck) the input voltage. It accepts an input voltage between 2.5V and 5.5V. The LM3355 is available with a standard output voltage of 4.1V (ideal for white LED applications). If other output voltage options between 1.8V and 4.1V are desired for other applications, please contact your National Semiconductor representative. The LM3355’s proprietary buck-boost architecture enables up to 50 mA of load current at an average efficiency greater than 75%. Typical operating current is only 375 µA and the typical shutdown current is only 2.3 µA. The LM3355 is available in a 10-pin MSOP package. This package has a maximum height of only 1.1 mm. The high efficiency of the LM3355, low operating and shutdown currents, small package size, and the small size of the overall solution make this device ideal for battery powered, portable, and hand-held applications. See the LM3352 for up to 200mA of output current. Features n Regulated VOUT with ± 3% accuracy n Standard output voltage of 4.1V n Custom output voltages available from 1.8V to 4.1V in 100 mV increments n 2.5V to 5.5V input voltage n Up to 50 mA output current n > 75% average efficiency n Uses few, low-cost extern...