A brand new 4-channel oscilloscope, disassembled... to see what's inside

First of all, we need to explain what a mixed domain oscilloscope is. Since we are talking about this topic, we have to talk about the evolution history of oscilloscopes. Next, I will briefly talk about the brief history of the evolution of oscilloscopes.

The first generation of oscilloscopes - analog oscilloscopes (ART-analog real time oscilloscope)
are pure analog machines that use oscilloscopes to display XY scanning imaging and waveforms. Later, they had character overlay functions that could realize simple measurement parameter display. The pinnacle was the Tektronix 7000 series. The Tektronix 485 in the figure below is one of the classics. The

second generation of oscilloscopes - digital oscilloscopes (DSO-digital oscilloscopes) are
digital machines that use AD converters plus DSP or FPGA as controllers to sample and process analog signals and display caches.

The third generation of oscilloscopes - digital phosphor oscilloscopes (DPO-Digital Phosphor Oscilloscopes)
use digital oscilloscopes as a basis to enhance waveform capture and processing capabilities, making them have waveform persistence functions similar to those of analog oscilloscopes and higher waveform refresh rates.

The fourth generation of oscilloscopes - mixed signal oscilloscopes (MSO Mixed Signal Oscilloscopes)
are based on digital phosphor oscilloscopes, adding logic analysis meaning digital channels on the basis of analog channels, and extending trigger channels to digital channels so that digital channels and analog channels can be measured and displayed simultaneously.
The representative work is Agilent 54622D

fifth-generation oscilloscope, which is also the protagonist today - the mixed domain oscilloscope (MDO Mixed Domain Oscilloscope)
adds spectrum analyzer function based on the digital oscilloscope, integrates time domain measurement (oscilloscope/logic analyzer are both time domain measurement instruments) and frequency domain measurement into one, and adds signal generator function. Digital channels, analog channels, signal generator channels and RF channels can be used together for measurement and analysis, which is a real all-in-one instrument.

OK! After a brief nonsense, the main text begins (please forgive me if I made some mistakes in the introduction).
First, let me introduce the origin of this machine - by chance,
it was a day in early summer of 2018. A friend of mine had just bought a machine. Since he was short of money and could not afford a high-bandwidth model, he bought the lowest 4-channel version of this series, MDO3014, with 100M analog bandwidth and 4 channels.

After using it for a few days, he found that the performance was a bit stretched, so he discussed with me to see if I could send it to him to crack the bandwidth or something. OK, I took it.

After waiting for a few days for SF Express's love, I received the brand new MDO3014 and

couldn't wait to start it up and try it out. After all, this machine is a new series and I have never used it or touched it before. The two brothers sat side by side to start

the machine and enter the measurement to see the analog channel. I felt that there was no difference,

so I tried the RF channel (I don't know how to use the spectrum analyzer, so I just poked around).

Put the two machines together and press the power button at the same time to see the startup speed... This side has entered the measurement, but his brother's BIOS self-test has not passed yet, let alone entering the system.


Forget it, let's take a look at the details. Machines with Windows system really can't expect a fast startup speed.

The operation panel has analog channels, RF channels, and digital channels. There are also some shortcut function keys. I have to say that the newly added search in the middle is very easy to use. Close-


up of the input channel interface. The analog channel interface is a tekVPI interface, which is common with the DPO series and compatible with ordinary BNC probes. The RF channel is an ordinary N-head

buttock interface, signal source output AUX output LAN VGA USB

Then I picked up the screwdriver and shouted a classic line from eevblog, Don't turn it on, take it Apart!

Remove the 4 screws on the back cover. Pull down the pants and

remove a circle of screws. Open the cover to

view the internal organs, including the fan and power supply (the main AC power supply is not shielded...) Close-up

of the power supply

Close-up of the small interface board on the butt, the chip is for AFG. Overview of


the acquisition board/mainboard.

Close-up of the DC power conversion part.

Overview of the main program CPU,

overview of the Freescale acquisition part, Tektronix customized ADC DMX

. Close-up of the main program FPGA, with the logic analyzer debug interface of the FPGA next to it. Close -up of the main sampling processor, there is a very confusing thing on


the Tektronix customization side. After looking over and over for a long time, I confirmed that it is connected to the circuit, but I don’t know what it is used for. Close-up of the main program CPU Close-up of the internal interface part, estimated to be the acquisition processor debug interface . The whole picture of the acquisition board core, except for the FPGA, the main chips are all Tektronix customized ICs ADC part Sampling processor part Main program There is an NVRAM next to the CPU with silk screen printed on it. Glue selectively, glue must be applied................Draw it carefully (glue is to prevent moisture in this area, which will cause NVRAM leakage and data loss) Turn over the acquisition board motherboard to have a look at the lower analog front end The interface where the analog signal of the front end channel board is sent to the ADC, and the high-speed connector is on the back of the acquisition board Close -up of the acquisition board Close -up of the AD clock on the acquisition board, the crystal oscillator is very cute Then fly the wires on the suspected point, buckle the shell, turn on the machine to measure the communication signal and try to crack it By the way, I really figured out how to crack it Model options and bandwidth can all be cracked. This machine was finally cracked to MDO3054+1G bandwidth option, and the spectrum was extended to 6G Finally, of course, I waited for the first counter adjustment. After a long time of tinkering, I have used this machine for a while, and it feels pretty good