Boost Converter Has High Efficiency at Light Loads

Abstract: This design note shows how a boost converter is designed from a quad Schmitt-trigger NAND gate and the MAX921, a comparator with integrated voltage reference. Consuming only microwatts of power, this 5V-to-15V boost converter provides low load currents with high efficiency. The efficiency is > 90% for load currents between 1mA and 8mA.
Maxim > App Notes > Amplifier and Comparator Circuits
Keywords: DC-DC converter, low load currents, boost converter, Schmitt-trigger NAND gate Jul 09, 1998

APPLICATION NOTE 110
Boost Converter Has High Efficiency at Light Loads


Abstract:This design note shows how a boost converter is designed from a quad Schmitt-trigger NAND gate and the MAX921, a
comparator with integrated voltage reference. Consuming only microwatts of power, this 5V-to-15V boost converter provides low
load currents with high efficiency. The efficiency is > 90% for load currents between 1mA and 8mA.

In most DC-DC converters, the normal supply currents do not allow high efficiency at low load currents. The circuit in Figure 1,
however, contains micropower comp