Connection Diagrams

20157402

Top View

DAP = GND

20157403

Directional Signal Paths Top View

(Refer to pin names for signal polarity)

TRI-STATE and Powerdown Modes

The DS08MB200 has output enable control on each of the

six onboard LVDS output drivers. This control allows each

output individually to be placed in a low power TRI-STATE

mode while the device remains active, and is useful to

reduce power consumption on unused channels. In TRI-

STATE mode, some outputs may remain active while some

are in TRI-STATE.

When all six of the output enables (all drivers on both chan-

nels) are deasserted (LOW), then the device enters a Pow-

erdown mode that consumes only 0.5mA (typical) of supply

current. In this mode, the entire device is essentially pow-

ered off, including all receiver inputs, output drivers and

internal bandgap reference generators. When returning to

active mode from Powerdown mode, there is a delay until

valid data is presented at the outputs because of the ramp to

power up the internal bandgap reference generators.

Any single output enable that remains active will hold the

device in active mode even if the other five outputs are in

TRI-STATE.

When in Powerdown mode, any output enable that becomes

active will wake up the device back into active mode, even if

the other five outputs are in TRI-STATE.

Input Failsafe Biasing

External pull up and pull down resistors may be used to

provide enough of an offset to enable an input failsafe under

open-circuit conditions. This configuration ties the positive

LVDS input pin to VDD thru a pull up resistor and the

negative LVDS input pin is tied to GND by a pull down

resistor. The pull up and pull down resistors should be in the

5k

Ω to 15kΩ range to minimize loading and waveform dis-

tortion to the driver. Please refer to application note AN-

1194, “Failsafe Biasing of LVDS Interfaces” for more infor-

mation.

Output Characteristics

The output characteristics of the DS08MB200 have been

optimized for point-to-point backplane and cable applica-

tions, and are not intended for multipoint or multidrop signal-

ing.

Multiplexer Truth Table (Note 4)

Data Inputs

Control Inputs

Output

SIA_0

SIB_0

MUX_S0

ENL_0

LO_0

X

valid

0

1

SIB_0

valid

X

1

1

SIA_0

X

X

X

0 (Note 5)

Z

X = Don’t Care

Z = High Impedance (TRI-STATE)

Repeater/Buffer Truth Table (Note 4)

Data

Input

Control Inputs

Outputs

LI_0

ENA_0

ENB_0

SOA_0

SOB_0

X

0

0

Z (Note 5) Z (Note 5)

valid

0

1

Z

LI_0

valid

1

0

LI_0

Z

valid

1

1

LI_0

LI_0

X = Don’t Care

Z = High Impedance (TRI-STATE)

Note 4: Same functionality for channel 1

Note 5: When all enable inputs from both channels are Low, the device

enters a powerdown mode. Refer to the applications section titled TRI-STATE

and Powerdown modes.

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