Tag Archives: Integrated circuit

Smallest mixed-signal oscilloscope with AWG packs Atmel’s ATXMEGA32A4U

An oscilloscope is an electronic test instrument designed to monitor varying signal voltages, typically as a two-dimensional graph of one or more electrical potential differences using the vertical or y‑axis, plotted as a function of time (horizontal or x‑axis).

A mixed-signal oscilloscope (or MSO) is often equipped with two types of inputs – a small number of analog channels (typically two or four) and a larger number of digital channels (16). The mixed-signal model is capable of accurately time-correlating analog and digital channels, thus offering a distinct advantage over a separate oscilloscope and logic analyzer. As such, digital channels may be grouped and displayed as a bus with each bus value displayed at the bottom of the display in hex or binary.

Recently, Saelig introduced the Xprotolab Portable, which the company describes as the smallest handheld mixed-signal oscilloscope with AWG (arbitrary waveform generation). The device – powered by Atmel’s ATXMEGA32A4U microcontroller – offers a combination of three electronic instruments: a mixed signal oscilloscope (simultaneously sampling of 2 analog / 8-bit/200kHz and 8 digital / 1MHz signals), an arbitrary waveform generator and protocol sniffer. The oscilloscope weighs less than 60g, is a compact 3.13″ x 1.83″ 0.7″ and boasts an integrated graphic 1.3” OLED to render waveforms on a 128×64 pixel display. In terms of connectivity, the Xprotolab Portable can link to a PC’s USB port for battery charging, external control, or screen dumps.

As a mixed-signal oscilloscope, the device offers simultaneous 2MSa/s sampling of 2 analog and 8 digital signals; as an arbitrary waveform generator it provides advanced sweep options on all waveforms; as a protocol sniffer, it can decode SPI, I2C and UART. The handheld mixed-signal oscilloscope also features an advanced triggering system, adjustable trigger level and the ability to view signals prior to the trigger.

As a portable DigitalMeter, the Xprotolab Portable displays VDC, VPP and input frequency to 12MHz, with XY Mode facilitating Lissajous Figures, the display of V/I curves and the phase difference between two waveforms. Meanwhile, an integrated FFT Spectrum Analyzer offers various windowing options, along with selectable vertical log and IQ visualization. Perhaps most importantly, the waveform generator and the oscilloscope can operate simultaneously, with the waveform generator running in the background.

And last, but certainly not least, the Xprotolab Portable AWG can output Sine, Square, Triangle and Exponential signals, as well as periodic noise that fills the AWG buffer with random data. In addition, a SWEEP feature increases one or more parameter values automatically on each screen refresh of the oscilloscope.

Accessories include one USBmini-USB-PC cable, two 3.5mm-EZhook signal probes and an 8-channel logic probe. An optional 3.5mm to BNC adapter facilitates the use of standard 10:1 scope probes for signal input, while an optional Tripod Adapter allows Xprotolab Portable to be mounted using a standard camera screwthread.

Additional information about the $98 Xprotolab Portable is available here.

Why on-chip EEPROM is cool

EEPROM costs more to make than flash memory. But you don’t have to write to it in blocks. And you can write to it more times without wearing it out. Flash is good for about 10k to 100k writes. EEPROM can do more.

Better yet, you can arrange the EEROM as a circular buffer so it is unlikely to ever wear out. That is a benefit of EEPROM, you don’t have to program it in blocks. The reason EEROM costs more is not simply the size of the cells. It’s that you need to do extra process steps. You have to realize that those extra process steps penalize the whole die, since you are adding steps to making a finished wafer.

So integrating EEPROM onto an MCU does have a cost penalty. But when you do it, you have some solid reliable non-volatile memory that can be written to individually instead of an entire block a time.

Adding EEPROM to some large die like an ARM core carries too much of a cost penalty, so you won’t see then there. But many Atmel MCUs have embedded EEPROM and you should check them out for any critical non-volatile functions you need in your system. If you do need some big iron, like an ARM core, well then you can always use some Atmel serial EEPROMs and have the same benefits in you larger systems.


When you live here in Silicon Valley, you get to meet all kinds of engineers. Some are programmers, some are hardware folks. But some of the most interesting are semiconductor process engineers, and their kindred spirits, the product engineer.

When you hang around those folks, you really do see how difficult it is to make the high-performance silicon that is coming out in this day and age. You might not directly see the work of the process engineers, but they are just as important as the IC designers, apps and test engineers in bringing you the remarkable parts you can use in modern designs.