Higher performance required from measuring instruments

	The new 200MHz MSO of type HMO2024 represents the top of the range of the entry class.

The oscilloscope is the undisputed most important and most used measuring instrument in electronics. For many years to come, the classical measuring tasks of signal tracing, timing analysis in a circuit, tests of signal integrity such as ripple measurement, transient behaviour or crosstalk will be basic requirements. But there are increasing problems regarding the checks of embedded systems where the designer or service technician, as a consequence of integration, can no longer reach important measuring points such as clock generator, memory or converters. New methods are now required to infer from measurements how those internal blocks function, so the design objectives and later requalification tests will be met.

Requirements will steadily rise

In modern circuit designs, numerous peripheral blocks such as input or output units are connected via serial buses like I²C, SPI or UART. In order to check the functionality of these blocks, the analysis of these protocols and a large memory are prerequisites. Evaluation of the clock generator including the correct function of a PLL and the clock distribution can often already be performed by looking at the supply voltage (fundamental and harmonics) using a sensitive input and a FFT with a sufficient number of points. While specifications like sensitivity, sampling rate or memory depth are the primary buying criteria, the ability to upgrade towards MSO and serial protocols at reasonable prices should not be underestimated.

When the new oscilloscope series for the entry segment was defined, all these criteria were considered. The extension of the popular HMO series by eight instruments (2-, 4-channel, 70 to 200MHz) was presented at the Embedded World. Many users just could not believe that an instrument with these performance features was available from a starting price of £1,025.00 – even including the serial bus analysis (during the year of introduction). „We adhere to our motto: Great Value in Test & Measurement“, Holger Asmussen, General Manager of HAMEG Instruments, said at the press conference. „Sensitivity, Accuracy, Quality and Simplicity remain our guidelines, which remain valid also after the takeover by Rohde & Schwarz in 2005.“ As a group of companies R & S as a German and hence the only European company addresses the bandwidth range of 40MHz to 2GHz, in addition to the three known US manufacturers.

The focus on MSO & Bus Analysis

Already with the new 2-channel 70MHz instrument HMO722 the serial triggering and decoding of I²C, SPI and UART/RS-232 protocols can be performed via the analog channels. With 3-conductor buses the external trigger input is also used. All instruments are MSO Ready and after buying a logic probe HO3508 they will be upgraded with 8 logic channels. Standard features are a powerful mask test, extended mathematics, (e.g. integration or digital filters), an integrated source of square wave signals, up to 4 bits wide random or counter patterns, I²C, SPI and UART signals with different data rates and a component tester. Unique is also the sensitivity of 1mV/div., together with the lowest noise and a whispering fan.

Source: Elektronik Praxis, Issue 07/11