Logic analyzer catches small timing differences
August 21, 2012Bus timing keeps getting tighter as speeds increase. As a result, you may not be able to see small differences in timing about signals. The TLA6400 series of logic analyzers, with 40 ps of timing resolution, lets you see those differences. A 25-GHz sampler is the key to that specification. Tektronix claims that this speed is six time faster than any other logic analyzer on the market today.
The series is available in four models depending on number of channels: 34, 68, 102, or 136 let you see bus timing on processors, memory, and other communications buses. The instruments also have state speeds up to 667 MHz and data rates up to 1333 Mbits/s.
In addition to showing you timing differences, the TLA6400 series has a feature called iCapture that lets you see up to four signals in analog form using logic-analyzer probes. Thus, you don’t need separate analog probes that can create additional loads on signals. A 2-GHz analog mux (see diagram), diverts signals to a four-channel digitizer.
The analog signals are also available as outputs through BNC connectors that you can connect to an oscilloscope. Alternatively, you can use iView software to capture analog signals on an oscillosocpe and view them time-correlated to the logic signals. The combination of analog and digital representations of signals lets you see analog characteristics that can affect logic levels that produce glitches or timing errors. The diagram shows how an unwanted level in the analog trace produces a glitch in the digital trace above it.
The TLA6400 series of logic analyzers contain a PC motherboard running Windows 7. That gives you a full suite of PC I/O ports such as USB, mouse, keyboard, LAN, RS-232, and VGA. A removable hard drive lets you keep data secure.
Prices for a 36-channel logic analyzer start at $11,600. www.textronix.com