Oscilloscope -A buyer's Guide
With the advance of technologies troubleshooting and testing has become more challenging. This requires digital storage oscilloscopes and real time spectrum analysis to debug the issues.
Low cost oscilloscope is always desirable among engineers and enthusiasts working in electronics industry. To meet the demand across the industries various manufacturers have come up with various oscilloscope options as per need of the users to buy. The popular companies include Teledyne Lecroy, Agilent ,Tektronix, Digilent, Link instruments, Parallax Inc. etc.
Now-a-days companies are providing multifunction support in the oscilloscope which includes other functionalities such as spectrum analyzer, logic analyzer, Arbitrary function generator, protocol analyzer and digital multimeter.
Following section mentions typical oscilloscope specifications based on different types of oscilloscopes.
1. Bandwidth: Range of frequencies which can be analyzed by the oscilloscope.
It the frequency where sinusoidal input is attenuated to about 70.7% value of its amplitude.
2. Sample rate: It is the parameter which specifies how often signal is sampled so that the signal can be re-constructed without any distortion from digital samples. As per nyquist, sampling rate should be greated than two times of maximum input signal frequency. But based on different interpolation techniques different sampling rate is adopted.
3. Record length: The time that will be captured by each of the oscilloscope channel is referred as record length.
Time captured = Record Length/ Sampling rate.
4. External Trigger: It helps stabilize waveforms to be viewed very easily. edge and pulse width trigger options are available.
5. Waveform capture rate: To capture fast transients of the time domain signal, higher capture rate oscilloscopes are needed.
6. Supporting Probe: It should be of same bandwidth as of oscilloscope.
Other than above mentioned basic specifications following oscilloscope specific specifications are required.
Following are the types of oscilloscopes based on different applications and need from engineers have been manufactured by companies.
|Bandwidth,sampling rate,external trigger,no. of channels,Automated waveform measurement,display size,I/O interfaces||Agilent,
|Model: 940-WAVEACE1001 supports BW of upto 40MHz at 1GS/s with 2 channels|
|Model DSO 094(dual channel) from Jyetech, UT81B from uni-trend etc.|
|Bandwidth,sample rate, multifunction support as mentioned above||Dynon
|Model MSO-19 from Link instruments supports 60MHz bandwidth, supports repetitive mode upto 1GS/s and single shot upto 200MS/S,supports multifinction feature.|
|Low cost design of our own. with bandwidth and sample rate||EO systems,
|eOscope with BW of 20 MHz and sample rate of 40MS/S|
|Multi function advanced features||R & S,
|R & S RTO from 600MHz to 4GHz, 6-in-1 MDO3000 mixed signal oscilloscope from Tektronix, Agilent Infniivision and Infriium series from 1GHz to 6 GHz.|
Following are few of the latest releases from leading manufacturers across the world.
Company: Teledyne Lecroy
Model: Wavesurfer 3000 series
Features: 10.1" touch screen, bandwidth from 200 to 500 MHz, 4GS/S sampling rate, 10Mpts/Channel memory
Cost: About $3200 to $6950 as on July,2014
Model: RTO Family
Features: Model RTO 1044 measures fast clock upto frequency of 800MHz with bandwidth of 4GHz. It supports 20Gs/s sampling rate. It can support interfaces with data rate of 1.6Gbps.