Product Info

XScopes Specifications

The XScopes

The XScopes are a combination of three electronic instruments: a mixed signal oscilloscope, an arbitrary waveform generator and a protocol sniffer. The XScopes can also be used as development boards for the AVR XMEGA microcontroller. The Xprotolab and Xminilab can be plugged directly on a breadboard.

Main Features:

  • Mixed Signal Oscilloscope: Simultaneous sampling of 2 analog and 8 digital signals.
  • Arbitrary Waveform Generator with advanced sweep options on all the wave parameters.
  • Protocol Sniffer: SPI, I2C, UART
  • Advanced Triggering System: Normal / Single / Auto / Free, with many trigger modes; adjustable trigger level, and ability to view signals prior to the trigger.
  • Meter Mode: VDC, VPP and Frequency readout.
  • XY Mode: For plotting Lissajous figures, V/I curves or checking the phase difference between two waveforms.
  • Spectrum Analyzer with different windowing options and selectable vertical log and IQ visualization.
  • Channel Math: add, multiply, invert, and average.
  • Horizontal and Vertical Cursors with automatic waveform measurements, and waveform references.
  • USB connectivity: Windows, Linux, MAC, Android

Specifications

    Xprotolab
xprotolab oscilloscope
Xminilab
xminilab oscilloscope
Xprotolab Portable
xprotolab portable oscilloscope

Xminilab Portable
The Xminilab Portable

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Microcontroller ATXMEGA32A4U 32KB+4KB Flash, 4KB SRAM, 1KB EEPROM
Display Type Graphic OLED, 128x64 pixels, max. refresh rate 122Hz
Display Size 0.96 inches 2.42 inches 1.3 inches 2.42 inches
Display Life Time 10,000 hours min. 40,000 hours min. 10,000 hours min. 40,000 hours min.
Device size 1.615” x 1.01” 3.3” x 1.75” 3.13" x 1.83" 0.7" 3.17” x 2.22” x 0.7”
Weight 8.6 grams 25 grams 60 grams 75 grams
Interfaces 4 Tactile Switches, USB (Micro USB connector), UART, PDI for debugging
Battery N/A LiPo 3.7V 600mAh LiPo 3.7V 750mAh
Active current 40mA to 60mA 45mA to 75mA 40mA to 60mA 45mA to 75mA
Sleep current 3.6mA 1uA
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Logic Inputs 8 Digital Inputs
Logic Input levels 3.3V only 3.3V, 5V tolerant
Input Pull None, 24kΩ Pull Up, or 24kΩ Pull Down 820kΩ Pull Down
Max. Sampling rate 2Msps
Buffer Size 256
Frequency Counter 16MHz, 1Hz resolution, +/- 100ppm accuracy
Sniffer Protocols UART, I2C, SPI
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Analog Inputs 2 Analog Inputs
Max. Sampling rate 2Msps
Analog Bandwidth 200kHz
Resolution 8 bits
Input Impedance 1MΩ
Buffer size 256 on each channel
Input Voltage Range -14V to +20V
Vertical Sensitivity 80mV/div to 5.12V/div
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Analog Outputs 1 Analog Output
Max. Conversion rate 1Msps
Resolution 8bits
Buffer Size 256
Output current > +/- 7mA
Output Voltage +/- 2V +/- 4V
Low Pass Filter 44.1kHz 53kHz

 

LED Driver

This is the LED driver used on the Oscilloscope Watch. The simulation below shows the circuit:

Sorry, you need a Java-enabled browser to see the simulation.

Right on the input there is a spark gap to help keep ESD events out of the amplifier. The high impedance of the input also helps to keep the circuit protected.

An AC/DC coupling switch is present; the AC path is done with a high voltage 0.1uF capacitor.

Let’s calculate the transfer function. At the V+ pin of the Opamp, we have:

$$V^{+}=V_{in}∙{180k}/(820k+180k)= V_{in}∙9/50$$

This voltage is amplified by the OpAmp, using the non-inverting amplifier circuit:

$$V_{Op}=V^{+}∙(1+{20k}/{180k})= V^{+}∙(1+1/9)= V_{in}∙9/50∙10/9=V_{in}/5$$

Then, the voltage needs to be shifted so it can be applied to the microcontroller, using the superposition theorem:

$$V_{out}=V_{in}/5∙{3k}/(3k+3k)+2.048V∙{3k}/(3k+3k)$$

And finally:

$$\bo V_{\bo \out}=V_{in}/10+1.024V$$

XScopes Analog Front End

The signal conditioning of the input is a simple voltage divider, a non-inverting amplifier, and a level shifter. The OpAmp selected is a TL064, which has a GBW of 1MHz, a slew rate of 3.5V/µs, and is low cost. The simulation below shows the front end circuit:

Sorry, you need a Java-enabled browser to see the simulation.

Right on the input there is a spark gap to help keep ESD events out of the amplifier. The high impedance of the input also helps to keep the circuit protected.

An AC/DC coupling switch is present; the AC path is done with a high voltage 0.1uF capacitor.

Let’s calculate the transfer function. At the V+ pin of the Opamp, we have:

$$V^{+}=V_{in}∙{180k}/(820k+180k)= V_{in}∙9/50$$

This voltage is amplified by the OpAmp, using the non-inverting amplifier circuit:

$$V_{Op}=V^{+}∙(1+{20k}/{180k})= V^{+}∙(1+1/9)= V_{in}∙9/50∙10/9=V_{in}/5$$

Then, the voltage needs to be shifted so it can be applied to the microcontroller, using the superposition theorem:

$$V_{out}=V_{in}/5∙{3k}/(3k+3k)+2.048V∙{3k}/(3k+3k)$$

And finally:

$$\bo V_{\bo \out}=V_{in}/10+1.024V$$