INTEGRATED DEVICE PROVIDING CURRENT-REGULATED CHARGE PUMP DRIVER WITH CAPACITOR-PROPORTIONAL CURRENT

摘要

An integrated circuit (10) regulates current flowing from a battery (18) to a load without requiring an external current sense resistor. The IC includes a primary charge pump (12); a model charge pump (14); a current sense circuit (U3, M2), a first control circuit to force a voltage level at the output of the model charge pump to be equal to a voltage at the output of the primary charge pump; and, a second control circuit to force a model current out by the model charge pump is regulated at a level established by the capacitance value of an external flying capacitor (Cp) irrespective of input voltage variation of the battery power source.