SMBus的I / O扩展控制LCD偏置电压

摘要：一个SMBus ™ I / O扩展，升压转换器，数字电位器组成的电路实现的SMBus控制的液晶显示屏的对比度。

Maxim > App Notes > DIGITAL POTENTIOMETERS DISPLAY DRIVERS

Keywords: LCD drivers, SMBus, I/O expanders, digital potentiometers, stepup converters Mar 14, 2005

APPLICATION NOTE 3467
SMBus I/O Expander Controls LCD Bias Voltage

Abstract: A circuit consisting of an SMBus I/O expander, step-up converter, and digital potentiometer
enables the SMBus to control the contrast of an LCD.

Small, handheld, battery-powered devices often feature an LCD panel and a microcontroller with limited I/O
pins. The SMBus is useful for controlling system functions under limited I/O and, for convenience, it should also
be able to control the LCD contrast. In Figure 1, this task is accomplished with an SMBus I/O expander (IC2), a
step-up converter (IC1), and a digital potentiometer (IC3).