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POWER DOWN

HIGH-IMPEDANCE MODE

SN65LV1021

SN65LV1212

SLLS526G – FEBRUARY 2002 – REVISED DECEMBER 2005

FUNCTIONAL DESCRIPTION (continued)

Once the deserializer has synchronized to the serializer, the LOCK pin transitions low. The deserializer locks to

three CMOS input gates (15-pF load, total for all three) with a 40-MHz clock.

When no data transfer is required, the power-down mode can be used. The serializer and deserializer use the

power-down mode, a low-power sleep mode, to reduce power consumption. The deserializer enters power down

when you drive PWRDN and REN low. The serializer enters power down when the PWRDN is driven low. In

power down, the PLL stops and the outputs enter a high-impedance state, which disables load current and

reduces supply current to the milliampere range. To exit power down, you must drive the PWRDN pin high.

Before valid data exchanges between the serializer and deserializer can resume, you must reinitialize and

resynchronize the devices to each other. Initialization of the serializer takes 1026 TCLK cycles. The deserializer

initializes and drives LOCK high until lock to the LVDS clock occurs.

The serializer enters the high-impedance mode when the DEN pin is driven low. This puts both driver output pins

(DO+ and DO-) into a high-impedance state. When you drive DEN high, the serializer returns to its previous

state, as long as all other control pins remain static (SYNC1, SYNC2, PWRDN, TCLK_R/F). When the REN pin

is driven low, the deserializer enters high-impedance mode. Consequently, the receiver output pins

the state of the PLL.

Deserializer Truth Table

INPUTS

OUTPUTS

PWRDN

REN

ROUT[0:9]

H

H

Z

H

Z

H

H

Active

L

Active

L

X

Z

Z

Z

H

L

Z

Active

Z

(1)

LOCK output reflects the state of the deserializer with regard to the selected data stream.

(2)

ROUT and RCLK are 3-stated when LOCK is asserted high.

(3)

RCLK active indicates the RCLK is running if the deserializer is locked. The timing of RCLK with

respect to ROUT is determined by RCLK_R/F.

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