There are many variations and improvements to the basic Dickson charge pump. Many of these are concerned with reducing the effect of the transistor drain-source voltage. This can be very significant if the input voltage is small, such as a low-voltage battery. With ideal switching elements the output is an integral multiple of the input (two for a doubler) but with a single-cell battery as the input source and MOSFET switches the output will be far less than this value since much of the voltage will be dropped across the transistors. For a circuit using discrete components the Schottky diode would be a better choice of switching element for its extremely low voltage drop in the on state. However, integrated circuit designers prefer to use the easily available MOSFET and compensate for its inadequacies with increased circuit complexity.Yuan, 14-21</ref>