
Receiver testing at signaling speeds above 8 Gbps requires precise attention to signal conditioning and equalization. Multi-Tap pre-emphasis is a common requirement where a pre-cursor, main-cursor and post-cursor controls are called out by receiver specifications. The LE320 and LE160 offer flexible controls permitting the user to tune these levels of pre-emphasis as needed for 100 G standards.
Multi-generational speeds require characterizing receivers against a wide array of physical channel loss profiles, which typically involves stocking up an array of backplanes or specialized reference channels. The flexible 9-tap filter configuration of the LE320 and LE160 can be structured to model a full passive frequency dependent loss profile. These profiles (loss or gain) can be stored and recalled electronically to facilitate silicon test under a broad set of conditions without the overhead of having many physical reference channels to test against.
The dynamic range of these linear equalizer output allows a user to apply precision output controls to regulate the amplitude from 2.7 V (differential peak to peak) to 0 V with a special output (Return to zero) mode of operation permitting continuous or burst mode tri-state signaling found in various power and state management applications such as LFPS or OOB measurements. These structured return to zero operations are key to power management state and link state training capabilities.
Data input (single-ended)
- Number of taps
- 9 physical taps standard with four time-domain mapped taps depending on the data rate.
- Operating data rate range
- LE160, 4 Gb/s to 21 Gb/s
LE320, 8 Gb/s to 32 Gb/s1
1Operation down to 8 Gbps is supported with single tap response.
- Coupling
- AC coupled
- Maximum data input level
- 800 mvp-p (typical)
- Data input sensitivity
- 40 mVp-p, (typical)
The minimum input signal level acceptable to the data input for proper operation
- Data input termination
- 100 Ω differential
50 Ω single-ended
- Connector type
- 2.92 mm female
- Input return loss
- (typical)
Data output (differential)
- Minimum settable amplitude range (DP/DN)
- 0 mVp-p to 2000 mVp-p maximum differential
Pattern: 1100, taps set for flat loss
- Settable amplitude resolution
- 0.15 dB (typical)
- Coupling
- AC coupled
Skew between DP and DN- <2 ps (typical), 4 ps (specified), taps set for flat frequency response
- Additive random jitter
- LE160
- 220 fsRMS (typical), input pattern 1100 1
- LE320
- 300 fsRMS (typical), input pattern 1100 1
1Additive Jitter. The LE320/LE160 can be configured to many conditions resulting in increased Data Dependent Jitter (DDJ) and Random Jitter (Rj), for example in a backplane emulation configuration. The LE320 can be tuned to have < 300 fs RJ RMS and < 6 ps of DDJ.
- Tap range
- -63 to +63 tap settings
- Tap resolution
- 1.6%, any tap
- Connector type
- 2.92 mm, female
- Zero output state timing constant
- ±600 mV, single ended signaling level to 0 V ±10 mV in ≤ 40 UI = 2.9 ns; idle state (fall time after enable asserted)
- Consecutive run length amplitude droop
- <10 % maximum droop (typical)
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