Analog Devices EVAL-ADN4680EEBZ, Руководство пользователя

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User Guide EVAL-ADN4680E
EVALUATION BOARD CONFIGURATION
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SETTING UP THE EVALUATION BOARD
The EVAL-ADN4680EEBZ allows the ADN4680E to be quickly
and easily evaluated. The EVAL-ADN4680EEBZ allows all of the
input and output functions to be exercised without the need for
external components. Jumper configurations are shown in Jumper
Connections .
The EVAL-ADN4680EEBZ is powered by connecting a 3.3 V power
supply to either the J1 VCC SMA connector or the VCC and GND
connections of the P6 screw terminal block. The supply current is
typically 8 mA with all drivers and receivers disabled. The C11 and
C13, 10 μF decoupling capacitors and the C12 and C14, 100 nF
decoupling capacitors are fitted at the VCC connectors. Several
100 nF decoupling capacitors are included at the supply pins of the
ADN4680E.
Each half-duplex transceiver of the ADN4680E contains both a
driver and receiver that can be individually enabled or disabled via
jumper options. Each driver can be enabled or disabled via the
DE1 to DE4 jumpers. Connect these jumpers to VCC to enable
the respective driver, and connect these jumpers to GND to disable
the respective driver. Similarly, each receiver can be enabled or
disabled via the RE1 to RE4 jumpers. Connect these jumpers to
GND to enable the respective receiver, and connect these jumpers
to VCC to disable the respective receiver. The DE1 to DE4 and
RE1 to RE4 signals can also be accessed via the P3 and P5 screw
terminal blocks for dynamic control via a processor or a signal
generator.
Each of the four receivers of the ADN4680E can be individually
configured for Type 1 or Type 2 operation, using the FS1 to FS4
jumpers. Connecting an FSx jumper to GND configures the respec-
tive receiver for Type 1 operation, while removing the FSx jumper or
connecting the FSx jumper to VCC configures that receiver for Type
2 operation.
The ADN4680E features a global device enable pin, ENP, that can
be accessed via the P1 jumper. When this jumper is connected
to GND, all drivers and receivers are disabled in a low power
shutdown state. When this jumper is connected to VCC, the state of
each transceiver is controlled via the DE1 to DE4 and RE1 to RE4
pins.
The ADN4680E high speed digital input signals, DI1 to DI4, and
receiver output signals, RO1 to RO4, are routed on length matched
traces with a 50 Ω characteristic impedance to GND. The DI1
to DI4 traces are terminated to GND with 50 Ω resistors, R11,
R13, R16, and R18, respectively. The RO1 to RO4 traces include
an optional placeholder for a load capacitor at C2, C8, C4, and
C9, respectively. For optimum signal integrity, the DI1 to DI4 input
signals and RO1 to RO4 output signals can be accessed via
dedicated SMA connectors, D1 to D4 and R1 to R4. Alternatively
the P2 and P4 screw terminal connectors can be used for easy wire
connections to a microprocessor. The connections to the P2 and
P4 screw terminal block are made via 0 Ω resistors, which can be
removed to eliminate any stub lengths along the interconnect.
The M-LVDS input and output signals, A1 to A4 and B1 to B4, are
accessed via SMA connectors. These A1 and B1, A2 and B2, A3
and B3, and A4 and B4 signals are routed as four length matched
differential pairs with a differential characteristic impedance of 100
Ω. These signals are terminated at the Ax and Bx pins of the
ADN4680E with 100 Ω resistors, R6, R9, R10, and R5, respectively.
An example evaluation of the ADN4680E driver and receiver is
shown in Figure 2 . A signal generator is connected via the D1 SMA
connector to DI1 with an input signal of 125 MHz, a 50% duty cycle,
and a swing of between 0 V and 3.3 V. The ENP jumper, P1, is
connected to VCC to set the enable global device power-up. The
DE1 jumper is set to VCC, and the RE2 jumper is set to GND, to
enable the driver of Transceiver 1 and the receiver of Transceiver 2,
respectively. The DE2 jumper is set to GND to disable the driver of
Transceiver 2 to avoid bus contention. Jumper FS2 is set to GND
to set the receiver of Transceiver 2 to Type 1 operation. The A1
SMA connector is connected to the A2 SMA connector, and the
B1 SMA connector is connected to B2 SMA connector. In addition,
oscilloscope probes are connected to DI1 (TP2), A2 (TP9), B2
(TP10), and RO2 (TP21).