86108B Precision Waveform Analyzer Module

Flex Apps:
86100D Mode:

Starting with firmware release A.06.90, 86100D Compatibility mode is no longer being actively tested and supported.

The 86108B Precision Waveform Analyzer module is a dual-channel electrical module with integrated, compliant clock recovery, and a built-in precision time base. This is a double-wide module that fills both slots in the mainframe. The 86108B requires an N1000A, 86100D, or 86100C. It does not work with an 86100A or 86100B. For optimum performance, N1000A-PLK or 86100D-ETR should be used with the Research and Development Package license installed (or legacy Enhanced Jitter Analysis Software, 86100D-200). Without these options, the features provided with the 86108B module will be reduced.

The minimum required firmware versions for this module are A.10.70 (86100-series) and A.01.70 (FlexDCA).

Maximum electrical signal input for 86108B modules is 3Vp-p single-ended. Damage will occur at input powers above this level.

To deskew the channel inputs, use external phase trimmers.

This module is compatible with the these 86100D configurations: Standard, Compatibility, and Legacy


SIRC data is available for the N1092-series DCA-Ms. The SIRC correction data is a digital filter that is used to:

  • Improve the response of the module's reference filters to more closely match an ideal receiver.
  • Enable non-standard reference receiver rates or bandwidths.
  • Increase the bandwidth of the channel by up to 50%.
  • Ensures that an eye diagram will look identical between different modules.
86108B SIRC Filter Ranges
Module/Option Channel Range1
Min SIRC Freq. Max SIRC Freq.
86108B Option LBW All N/A N/A
86108B Option HBW All 25 GHz 75 GHz
  • 1 Only available with option IRC and compliance not guaranteed.

Automatic Relock

If the clock recovery module loses lock, the trigger becomes asynchronous with the data and the instrument will not display a correctly triggered waveform. By default, when lock is lost, the instrument automatically tries to re-establish lock. Automatic relocking is most helpful when probing a device under test. You can turn off or on automatic relocking from the Clock Recovery setup dialog. Loss of lock, or false lock, conditions may be caused by unusual patterns with a large amount of consecutive 1's or 0's. If the module loses lock during any procedure or measurement, reestablish lock and then repeat the procedure or measurement. For example, if lock is lost while saving a pattern waveform to a file, the data stored in the file will be corrupt.

Locking on the Data Rate

When using the module, you must specify the symbol rate of the clock to be recovered and lock the module on the symbol rate. Under two conditions, the module may lock on a symbol rate other than the specified rate. In the first condition, lock can occur if the entered symbol rate is an integer multiple of the actual symbol rate of the signal. The second condition occurs because the acquisition range is broad (greater than ±5000 PPM). This makes it possible for the module to lock on a signal that is higher or lower than the selected value. For example, if you select a 2.48832 GBd symbol rate but the signal is actually 2.5 GBd, the module may still lock on the signal.

Loop Bandwidth and Jitter

When measuring jitter relative to the recovered clock, jitter that is present on both the data and the recovered clock can not be detected by the instrument. Jitter that is within the clock recovery module's loop bandwidth appears on the recovered clock. Jitter that is outside of the loop bandwidth does not appear on the recovered clock and can be detected on the data.

Specific jitter frequencies in the vicinity of the loop bandwidth may appear amplified or attenuated due to the scope timebase delay and clock recovery group delay. The electrical through-path does not have a delay line. Compensation can be made, by adding an electrical cable between the electrical output and the vertical channel. However, this may affect signal quality.

If the display shows a clock recovery lock lost status message, clock recovery cannot be established on the signal. Make sure that your signal is attached with a power level greater than the minimum (see the specifications) and that the symbol rate is set correctly to within the specified acquisition range.

To use the front-panel clock above 3.2 GBd, Keysight 86108B modules require an instrument with the enhanced trigger option. Or, the front panel output divide ratio must be set on the 86108B to reduce the frequency below 3.2 GHz.

Aux Input

86108B Option 400 modules include a front-panel auxiliary clock recovery input. This front-panel input can provide improved performance in the following situations:

  • Marginal Input Signals
  • Improved Phase Noise Measurements
  • Measurements on Data Rates Above the 14.2 GBd Channel Input Limits

Available Options

Item Description
Bandwidth Options
86108B–HBW 50 GHz BW, two channel electrical.
86108B–LBW 35 GHz BW, two channel electrical.
Clock Recovery Options
86108B–216 Clock recovery input symbol rate range of 0.05 GBd to 16 GBd (continuous).
86108B–232 Clock recovery input symbol rate range of 0.05 GBd to 32 GBd (continuous).
86108B–300 Clock recovery adjustable loop bandwidth continuous-tuning range of 15 kHz to 20 MHz. Available loop bandwidth settings also depend on the symbol rate of the input signal. This option is automatically included with every 86108B module. The module can not be ordered without this option.
86108B–400 Auxiliary Clock Recovery Input. This option is automatically included with every 86108B module.
86108B–JSA Jitter Spectrum Analysis and Clock Recovery Emulation.
Precision Timebase Options
86108B–PTB Precision Timebase, ultra-low random jitter. This option is automatically included with every 86108B module.

Supplied Accessories

Item Qty
Suppled with Option 86108-HBW
Phase trimmers for external skew adjustment (2.4 mm) 2
DC Block (2.4 mm) 2
Cable Pair, matched (2.4 mm), 24 in. long 2
2.4 mm (f) to 3.5 mm (f) adapter 2
Suppled with Option 86108-LBW
Phase trimmers for external skew adjustment (3.5 mm) 2
DC Block (3.5 mm) 2
Cable Pair, matched (3.5 mm), 18 in. long 2

See Also