高效率升压转换器夺取并行端口

电路窃取从并行端口，功率为 8mA 在 5V 提供效率高达 94%。

Maxim > App Notes > AMPLIFIER AND COMPARATOR CIRCUITS POWER-SUPPLY CIRCUITS

Keywords: power conversion, parallel port, stepup switching converter, Schottky diodes Mar 14, 2005

APPLICATION NOTE 3468
High-Efficiency Step-Up Converter Robs Parallel Port

Abstract: Circuit including a step-up switching converter steals power from a parallel port, providing 5V at 8mA
with efficiency as high as 94%.

The circuit of Figure 1 steals energy from a parallel port or from any limited-energy source. Such power-
conversion applications usually require very high efficiency for making use of the energy available. A parallel-
data port, for instance, provides as much as 2.6mA per data line at 2.4V. When the eight data lines are software-
configured to FFHEX (all high), that conditi