基于TFT彩屏液晶的便携数字存储示波器

Portable DSO Based on TFT Colorized LCD

设计了一种以TFT彩屏液晶模块为显示器件的新型便携数字存储示波器。示波器的信号调理电路通过CA3338E的输出信号控制两级AD603放大,结合单片机控制继电器对信号进行衰减,实现了程控衰减放大和自动增益控制的功能。对于A/D采集到的信号,在单片机内部开辟RAM存储区对波形数据进行循环缓存,达到了边采集边显示的控制效果。在对波形显示的控制中,使用数字化的触发器代替传统的硬件触发电路,降低了系统的复杂度,借助于正弦插值技术,使屏幕显示的波形连续稳定。该示波器可以用来显示常用信号的波形,并进行相关参数的测量显示,具有输入信号的动态范围大,体积小,便于携带的优点,具有广泛的应用空间。

A new kind of portable digital storage oscilloscope （DSO） with TFT colorized LCD as its display device is developed. The signal modulation circuit of the oscilloscope uses the output signal of CA3338E to control the amplification of the two-order AD603. The attenuation of input signal is implemented by relays controlled by MCU. The function of both program-controlled attenuation/amplification and automatic gain control are realized. For the digital signal acquired by A/D chips, two slices of RAM are adopted to restore the wave data in the form of cycle storage, thus the effect of acquisition while displaying is realized. As for the control of the waveform display, a digital trigger is designed instead of the traditional hard- ware triggering circuits. In this way, the complexity of the system is reduced. With the help of sinusoidal interpolation algorithm, the wave displayed on the screen is both continuous and stable. This kind of oscilloscope can be used to display the wave of common signals, and measure the relevant parameters in the meanwhile. It has a wide dynamic range for the input signal and a broad space of application, and is small in size and portable.