Datasheet
Evaluates: MAX4889B/MAX4889C
6) Use a single SMA cable to connect the clock input
of the pattern sync module of the digital serial ana-
lyzer to the clock output of the pulse data generator.
7) Use the other pair of SMA cables to connect the
two sampling channels of the digital serial analyzer
to AIN+ and AIN- (P1 and P2) of the EV kit.
8) Set the digital serial analyzer to infinite persistence
and select the math function of the signal ((AIN+) -
(AIN-)).
9) Adjust the vertical scale to 100mV/div and horizon-
tal scale to 200ps/div on the digital serial analyzer.
10) Turn on the DC power supply.
11) Enable the data and clock outputs on the pulse
data generator and observe the waveform on the
digital serial analyzer.
12) Save the waveform on the digital serial analyzer.
13) Disable the data and clock outputs of the pulse
generator.
14) Turn off the DC power supply.
15) Remove the pair of SMA cables connected to
AOUTA+ and AOUTA- (P5 and P6) of the EV kit and
connect the cables to R_AOUT_+ and R_AOUT_-
(P9 and P10) of the EV kit.
16) Remove the pair of SMA cables connected to AIN+
and AIN- (P1 and P2) of the EV kit and connect the
cables to R_AIN+ and R_AIN- (P7 and P8) of the EV
kit.
17) Enable the data and clock outputs on the pulse
data generator and observe the waveform on the
digital serial analyzer.
18) Compare the waveform to the waveform that
includes the MAX4889B and observe the jitter/eye
height of both systems. Take the difference in
jitter/eye height, which is the extra jitter/eye height
coming from the MAX4889B.
Detailed Description of Hardware
The MAX4889B EV kit provides a proven design to evalu-
ate the MAX4889B PCIe Gen II 5.0Gbps passive switch.
The MAX4889B is a quad double-pole/double-throw (4 x
DPDT) switch ideal for switching four half lanes of PCIe
data between two destinations. The MAX4889B EV kit is
used for critical tests (e.g., eye diagrams and s-parame-
ter measurements such as insertion loss, return loss, and
off-isolation).
For simplicity, only one channel of the device is used in
the EV kit. Only the AIN_, AOUTA_, and AOUTB_ sig-
nals are used in the EV kit. All signal traces coming out
of the MAX4889B are 100Ω differential controlled-
impedance traces. Once the traces split into separate
directions, the traces are 50Ω single-ended controlled
impedances, which is equivalent to 100Ω differentially.
The MAX4889B operates from a 3.0V to 3.6V supply.
Calibration Trace
At the bottom of the EV kit board are calibration traces
used as a reference to differentiate the performance of
the switch from the traces and SMA connector provid-
ing a complete analysis of the MAX4889B.
No Load
The first calibration traces are made with no load. The
lengths of the traces are equal to the above circuitry
minus the MAX4889B. The traces starting from R_AIN_
and R_AOUT_ are 50Ω single-ended controlled imped-
ances. Once the traces run parallel to each other, and
are matched side by side, the traces are 100Ω differen-
tial controlled impedances.
Load
The second calibration traces are made with a 50Ω
load. The lengths of the traces are half the calibration
traces without the load.
Jumper Selection
Table 1 shows the control input for SEL. The MAX4889B
EV kit default setting is JU1 in the 2-3 position, which
selects the signal’s path between AIN_ and AOUTA_.
Move JU1 to the 1-2 position to test the quality of the
signals between AIN_ and AOUTB_.
MAX4889B Evaluation Kit
2 _______________________________________________________________________________________
Table 1. SEL Control Input (JU1)
JUMPER
SHUNT
POSITION
DESCRIPTION
1-2
Selects signal path between AIN_
and AOUTB_ channels
JU1
2-3*
Selects signal path between AIN_
and AOUTA_ channels
*
Default position.