Texas Instruments TLK1501, User Manual

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2-2
The board is normally delivered in a default configuration that requires external
clock and data inputs. The TLK1501 is shipped with jumpers for default
operation. Table 2–1 shows the default configuration for sending data.
Table 2–1. Default Transceiver Board Configuration as Shipped
Designator Function Condition
J5 GTX CLK SEL Jumper installed – Provides a method of supplying an input clock to
the board
J7 TESTEN Jumper installed (Logic 0)
Disables the TLK1501 test mode
J7 PRBSEN Jumper installed (Logic 0)
Disables the TLK1501 PRBS internal production test mode
J7 LCKREFN Jumper not installed (Logical 1)
Locks to received clock
J7 ENABLE Jumper not installed (Logical 1)
Enables the device for normal operation
J7 TXER Jumper installed (Logic 0)
Puts the TLK1501 in a state to transmit TX bus data
J7 LOOPEN Jumper installed (Logic 0)
Disables the TLK1501 internal loop back mode
J7 TXEN Jumper not installed (Logical 1)
Puts the TLK1501 in a state to transmit TX bus data
L3 VDD– bridge –VDDA Joins VDD and VDDA power planes
C24, C25 TX ac-coupling
capacitors
These capacitors (normally installed) are provided to ac-couple the
transmitted signal.
C22, C23 RX ac-coupling
capacitors
These capacitors (normally installed) are provided to ac-couple the
received signal
Note: For details, see TLK1501 data sheet
Table 2–2. Configuration Changes Necessary for DC Coupling of the High Speed Signals
Designator Function Condition or Changes Necessary for DC Coupling
C24, C25 TX ac-coupling
capacitors
Install zero ohm resistors
C22, C23 TX ac-coupling
capacitors
Install zero ohm resistors.
R34 RX bias resistor Install zero ohm resistor.
R33 RX bias resistor Uninstall resistor (open circuit)
R37, R38 TX termination
network
Uninstall resistors (open circuit) – Termination and pullup is achieved
at the receiver. Differential swing is increased.