Digital Storage Oscilloscope 500mhz Bandwidth Analog Channel Design

Analog channels are pivotal part of Digital Storage Oscilloscope(DSO).The bandwidth of DSO'analog channels is the evaluation of several key indicators of performance. With the continuous development of oscilloscopes, To meet the design needs to be designed with its trigger bandwidth of 500MHz and channel access control circuit, in order to complete the oscilloscope to test the accuracy of signals to be automatically corrected by adding the design module.This paper will introduce the DSO's analog channel design,whose bandwidth is up to 500MHz. The main task of this design is 500MHz bandwidth analog signal conditioning vertical channel design,foe 500MHz trigger channel design.Vertical signal conditioning channel is the most important part of the DSO's analog channel design. In this paper, the powerful Digitally Controlled,Variable Gain Amplifier, high-speed differential amplifier, as well as more mature passive attenuation network and impedance transformation network of are used to design theanalog signal conditioning channel,whose bandwidth is 500MHz. The parts of channel gain reduction are changed from the original three parts to two parts, add the stability of the circuit and reduce the difficulty of debugging. the signal is put into a differential signal,after the impedance transformation network,which enhanced the noise suppression circuit and the anti-jamming.The trigger channel selected more high-performance analog MUX, video splitters, and high-speed comparators. in the provision of high-qua-lity edge sync signal and video synchronization signals, it also sim-plifies the circuit.Access control using the string of better performance and converter, stored in the chip built-in features to enhance the stability of the circuit.Self-calibration module uses a higher precision operational amplifier, to improve the accuracy of the calibration voltage.