Tektronix probes in tight corners up to 20GHz

Tektronix has introduced a range of slim-line flexi oscilloscope probes for high-speed signals that put a fast – in one case 20GHz – 0.4pF 100kΩ amplifier less than 4mm from the probe tip.

Tektronix P77STFLXA probe

“Efficient test and debug of standards from LPDDR4 to MIPI D-PHY and C-PHY requires probes that minimise signal loss to cope with the challenging combination of high-performance and low power,” said the firm. “Another challenge is gaining access to signals on increasingly small devices, and multiple probe connections are often required – to capture signals on lanes of a MIPI bus or, for LPDDR memory, the data, strobe, and clock signals.”

Apart from the ‘browser’ (see below), the P7700 series of probes as they are known are solder-in types. Adjacent to the solder pads is a miniature (physically-rigid) differential amplifier, then a long flexi-PCB leading to a connector for a more conventional cable.

“The P7700 series probes use the new TekFlex connector that combines a high speed signal path with power and communication support for an active buffer tip in a single connector,” said Tektronix. “The connector has a pinch-to-open design that when open requires minimal force to attach an accessory tip.”

P77STFLXA is the 20GHz version, whose important differential specs are: 27ps rise time (10-90%), 0.4pF+100kΩ input, +/-5Vp-p (2.5Vp-p single-ended) and +/-4V offset range. DC gain accuracy is 2% and noises is <32nV/√Hz.

By augmenting the flexi-PCB with coaxial cables, a longer version called P77STCABL retains the same figures.

Slower versions are: P7716 (16GHz 32ps), P7713 (13GHz 40ps) and P7708 (8GHz 55ps).

Tektronix P7700 browser probeFor nipping about a PCB without soldering, there is the 16GHz P77BRWSR hand-held ‘browser’, intended for probing fine-pitch components and differential signal tracks spaces as close at 0.8mm.

Its tips are beryllium copper for strength and compliance, and to assist alignment there is a built-in headlamp.

Critical differential figures are: 32ps rise time (10-90%), 0.8pF+ 144kΩ input, 12Vp-p (6Vp-p single-ended) and +/-10V offset range. DC gain accuracy is 2% and noise is <80nV/√Hz.

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