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MAX
(3V)
MIN
(1V)
NOM
(2V)
VADJ BJ
ON
VADJ
OFF
(3.8V)
GLOBAL
VOLTAGE
ADJUST
JMP56
JMP57
MAX
(3V)
MIN
(1V)
NOM
(2V)
VADJ BJ
ON
VADJ
OFF
(3.8V)
GLOBAL
VOLTAGE
ADJUST
JMP56
JMP57
MAX
(3V)
MIN
(1V)
NOM
(2V)
VADJ BJ
ON
VADJ
OFF
(3.8V)
GLOBAL
VOLTAGE
ADJUST
JMP56
JMP57
MINIMUM VOLTAGE
SELECTED
NOMINAL VOLTAGE
SELECTED
MAXIMUM VOLTAGE
SELECTED
MAX
(3V)
MIN
(1V)
NOM
(2V)
VADJ BJ
ON
VADJ
OFF
(3.8V)
GLOBAL
VOLTAGE
ADJUST
JMP56
JMP57
VADJ BANANA JACK
SELECTED
MAX
(3V)
MIN
(1V)
NOM
(2V)
VADJ BJ
ON
VADJ
OFF
(3.8V)
GLOBAL
VOLTAGE
ADJUST
JMP56
JMP57
REGULATORS
DISABLED
(JMP57 SHUNT
POSITION IS A
DON’T CARE)
Power
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The regulators can also be disabled using this voltage window detect circuit by placing the shunt between
the center pin and the OFF pin of JMP56. This places 3.8 V on the input to the voltage window
comparator circuit which is set for 3.75 to 4.0V and turn on a FET connected to the Enable pin of the
regulators. 3.8V is used because it is within the window and the voltage reference chip used produces a
4.096-V voltage and 4 V may be too close to the high limits established by this reference chip. The
placement of the shunt on JMP57 is irrelevant if the OFF position on JMP56 is selected because it
overrides any min, nom, max setting. See the Power Regulator Min/Nom/Max Adjustment page 16 of the
TLK6002EVM schematics for more information on how this circuitry is connected.
Any combination of local regulator control, global regulator control, and external power supplies can be
implemented through the appropriate configuration of the various headers.
Figure 4. TLK6002 EVM Global Regulator Margin Selection
A large 1210 0-
Ω
resistor has been installed at the voltage entrance point of each power plane and can be
replaced with a ferrite bead of an appropriate value depending upon the desired data rate if desired. See
the Power Distribution page 18 of the TLK6002EVM schematics for more specific information on how all
the power planes are connected and sourced from either the banana jacks or regulators.
The VREFT plane is sourced through a voltage divider providing half of the voltage on the 1p5/8V plane.
The VDDQA/B, VDDRA/B, and VDDO1/2/3 power pins of the TLK6002 can be operated off of either 1.5 V
or 1.8 V with VREFTA/B being half of whatever voltage is on the VDDQA/B pins which is on the 1p5/8V
plane. The VREFT plane can be powered through the plane monitoring header (JMP4) and removing the
0-
Ω
resistor (R181), although this is not recommended. A separate VDDRA and VDDRB plane has been
added as no relationship exists between the VDDRA/B pin and the VDDQA/B pins; however, the
VDDRA/B planes are sourced through 0-
Ω
resistor (R176 and R177) from the voltage on the 1p5/8V plane
that provides power to the VDDQA/B and VDDO1/2/3 pins. These resistors can be replaced with a ferrite
bead or removed completely and an external supply can be connected to the VDDRA header (JMP8) and
VDDRB header (JMP7) in the case different voltages are desired on the two planes.
Furthermore, for more accurate current readings, the PULLUP_EN jumpers on all control pin headers can
be removed, quickly disconnecting the pullup resistors from the voltage plane. However, the removal of
the PULLUP_EN jumpers also requires manual high/low control of every control pins.
8
TLK6002 Dual-Channel, 0.47-Gbps to 6.25-Gbps, Multi-Rate Transceiver
SLLU132 – October 2010
Evaluation Module
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