SP6681

® SP6681 PRELIMINARY INFORMATION High Efficiency Boost Charge Pump Regulator FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Ideal for Li Ion or 3V to 5V Conversion Low Profile, Inductorless Regulator Up To 96% Power Efficiency +2.7V to +5.5V Input Voltage Range 5.0V, 50mA Output, 4% Accuracy Low EMI Design Low Quiescent Current: 175µA Low Shutdown Current: 4µA Optional External Clock: 32.768kHz Thermal Shutdown Protection Programmable Frequencies: 8.192kHz, 32.768kHz, or 262.14kHz ■ Internal Oscillator: 16kHz or 130kHz, when CLK Pin Is Held High ■ Ultra small 10-Pin MSOP Package APPLICATIONS ■ ■ ■ ■ ■ GSM SIM Card Power Supplies 3V to 5V Boost Applications Li Ion to 5.0V Boost Applications White LED Driver Smart Card Readers DESCRIPTION The SP6681 is a charge pump ideal for converting a +3.6V Li-Ion battery input to a +5.0V regulated output. An input voltage range of +2.7V to +5.5V is converted to a regulated output of 5.0V. The SP6681 device will operate at three different switching frequencies corresponding to three different output resistances and load current ranges. An external 32.768kHz nominal clock signal is used to produce three synchronized pump frequencies through the use an internal phase lock loop to drive the charge pump. Two control inputs can adjust the internal pump frequency on the fly to 8.192kHz (fINPUT / 4), 32.768kHz (fINPUT x 1), or 262.14kHz (fINPUT x 8). The charge pump configuration dynamically changes to optimize power efficiency. At low input voltages the char...