The MAX861ESA+ is a 50mA, frequency-selectable, switched-capacitor voltage converter in 8 pin NSOIC package. This is a capacitive charge pump either invert or double the voltage applied to their inputs. i.e. invert the input voltages ranging from voltages ranging from +1.5V to +5.5V or double input voltage ranging from +2.5V to +5.5V. Because of its high switching frequency, this device uses only two small low-cost capacitors. The 50mA output makes switching regulator unnecessary and eliminates inductor and their associated cost, size and EMI. A frequency-control (FC) pin provides three switching frequencies to optimize capacitor size and quiescent current and to prevent interference with sensitive circuitry. It is used in operational-amplifier power supplies and interface power supplies.
Voltage conversion efficiency is 99.9% at no load
Power efficiency at 50mA is 87%
Shutdown supply current is 1μA
Voltage drop is 600mV at 50mA load
Output resistance is 12ohm at IL = 50mA
Switching frequency is 13KHz at FC = VDD
Time to exit shutdown is 500μs at no load, VOUT = -4V
Output current is 100mA at VDD = 5V, VOUT more negative than -3.75V