Archive for Equipment Review

Dino-Lite USB Digital Microscopes Review and Experiments

DinoLite

In this episode Shahriar takes a close look at some of Dino-Lite’s USB Digital Microscopes and accessories. Two of the microscope stand offerings from Dino-Lite are demoed (model MS36B and RK-10) with a close look at their features and usability. All USB stands offer precision Aluminum bodies and flexible ranges of motion for a variety of viewing angles and distances.

Three USB Digital Microscopes from Dino-Lite are also demoed: models AM4113ZTL Dino-Lite Premier, AM4515ZTL Dino-Lite Edge and AM4815ZTL Dino-Lite Edge. These microscopes offers features such as large magnification combined with long working distances, adjustable polarizer, adaptable cap design, MicroTouch shutter button, extended depth of field (EDOF), extended dynamic range (EDR) and automatic magnification reading (AMR) which are all compatible with the provide DinoCapture 2.0 interface software.

Using Dino-Lite’s microscopes, a variety of electronics components are presented: An Analog Devices PCB containing 0102 footprint components, A PIC UV erasable Silicon die, a 325GHz horn antenna, a composite wafer probe with 150um pitch from GGB industries. Finally, the complete breakdown of a QuinStar mm-wave PA module is shown with microwave filters, pre-amplifiers, and a Wilkinson-based GaAs PA as a final stage.

Tutorial on the Theory, Design and Characterization of Delta-Sigma Analog to Digital Converters

DeltaSigmaADC

In this episode Shahriar explores the world of Delta-Sigma modulators with emphasis on a Delta-Sigma Analog to Digital Converter (ADC). The basic concepts of analog to digital conversion is presented, particularly with respect to quantization noise spectral shape and power density. Next, oversampling ADCs are presented to demonstrate the possibility of increasing SQNR (ENOB) through manipulation of quantization noise spectrum.

Due to the practical limitations of high oversampling ratios, delta-sigma modulations is explored. The principle operation behind delta-sigma ADCs is presented with detailed explanation on noise shaping, filtering and decimation. The signal and noise transfer functions for a 1st order and 2nd order delta-sigma ADC are derived. Finally, as a practical example, a 2nd order delta-sigma ADC based on a 1-bit quantizer is presented. The ADC uses two Miller integrator op-amps, one comparator and a D-Type flip-flop. The complete measurement of this delta-sigma ADC is presented. The impact of over sampling ration, op-amp linearity and input signal bandwidth is presented. The slides for this video can be downloaded here.

Tutorial on Programming the NeoPixel (WS2812) RGB LEDs & Equipment Giveaway!

NeoPixel

In this episode Shahriar takes a close look at programming the popular NeoPixel RGB LEDs using a PIC microcontroller and C-language. A close-up of the NeoPixel (WS2812) LED is shown with attention to identifying various semiconductor elements inside the package. The principle operation of the LED is the described along with a detailed explanation of the pins and the one-wire communication protocol.

A simple evaluation board for the PIC18F4550 is used to drive a circular array of 60 NeoPixel LEDs from Adafruit. After presenting the difficulties of providing an accurate pulse-shape using the C-language, the measured waveform is shown on a Tektronix MDO4000B. Finally, the code for a circular color rotating pattern is presented and demoed. The code for the experiment can be downloaded here.

There is also equipment giveaway! A TPI Scope Plus 440 and a Tektronix TDS2232 are being given away at no charge! Please leave a comment on the video or on the website. You must be a resident of the USA to receive the giveaway. A winner will be chosen at a later date and notified via email.

Teardown, Repair and Experiments of an Agilent 86120B Multi-Wavelength Meter

86120B

In this episode Shahriar repairs an Agilent 86120B Multi-Wavelength Meter. The instrument reports “E14 Data Acquisition Problem” which corresponds to a potential internal HeNe reference laser failure. After the instrument disassembly, the old HeNe laser is removed and its optical power is compared to that of a new laser. The measurements confirm that the old laser has significantly deteriorated in output light intensity. The new laser is fitted inside the unit and the error message is eliminated. The free-space optic portion of the instrument is revealed and the principle operation is reviewed. Various components of the Michelson Interferometer is examined.

To test the correct operation of the instrument, a single tone semiconductor laser is applied to the unit and the result is compared to a different wavelength meter. The concept behind the operation of a Fabry-Perot laser is also presented before the signal is applied to the wavelength meter.

 

Tektronix MDO4104B-6 Mixed Domain Oscilloscope (MDO4000B) Review and Experiments

MDO4000B

In this episode Shahriar reviews and demos the second revision of the industry’s first Mixed Domain Oscilloscope from Tektronix. The MDO4000B series offers improved signal integrity and performance. The reviewed model is a MDO4104B-6 which offers 16-Channel Logic Analyzer, 4-Channel Oscilloscope with 1GHz of analog bandwidth as well a 6GHz Spectrum Analyzer with greater than 1GHz of instantaneous capture bandwidth with 65dB of dynamic range.

After an overview of the instrument’s interfaces and built quality, the block diagram and principle operation of the instrument is explained. The time-correlated digital, analog and RF capturing capability is described and its advantages for debugging complex mixed-domain systems is explored. Instrument probes, accessories and various modules are also presented.

The instrument is used to measure an ultra-pure single-tone signal at various frequencies for THD, SFDR and dynamic range measurements. For the main demonstration, a complete I/Q modulator system prototype is presented. The prototype includes a Maxim MAX2721 modulator, external PA, antenna diversity switch SW-277, digital control circuitry, power-grid DC-DC converters, external step attenuators, an Agilent E4342B synthesizer for LO generation and an Agilent N6020A arbitrary waveform generator for baseband signal generation. The Tektronix MDO is used to monitor RF, baseband, digital and power-supply analog waveforms. The system includes an array of problems including intermittent spurious tones, power supply dependent spectral noise, antenna switching glitches and 256-QAM constellation imperfections. The MDO is used to analyze, measure and solve all system problems. Tektronix SignalVu is used to analyze the system performance. As a final experiment, the MDO is used to demodulate a 1GHz bandwidth 32-QAM 500MS/s signal centered at a 3GHz carrier. The experiment documents can be downloaded here.