1 Features

• Low-Voltage Differential 30Ω to 55Ω Line Drivers

and Receivers for Signaling Rates(1) Up to

250Mbps; Clock Frequencies Up to

125MHz

• Meets or Exceeds the M-LVDS Standard TIA/

EIA-899 for Multipoint Data Interchange

• Controlled Driver Output Voltage Transition Times

for Improved Signal Quality

• –1V to 3.4V Common-Mode Voltage Range Allows

Data Transfer With 2V of Ground Noise

• Bus Pins High Impedance When Driver Disabled

or VCC ≤ 1.5V

• Independent Enables for each Driver and Receiver

• Enhanced ESD Protection: 7kV HBM on all Pins

• 48 pin 7 X 7 QFN (RGZ)

• M-LVDS Bus Power Up/Down Glitch Free

2 Applications

• Parallel Multipoint Data and Clock

Transmission Via Backplanes and Cables

• Low-Power High-Speed Short-Reach Alternative to

TIA/EIA-485

• Cellular Base Stations

• Central-Office Switches

• Network Switches and Routers

3 Description

The SN65MLVD040 provides four half-duplex

transceivers for transmitting and receiving Multipoint-

Low-Voltage Differential Signals in full compliance

with the TIA/EIA-899 (M-LVDS) standard, which

are optimized to operate at signaling rates up to

250Mbps. The driver outputs have been designed to

support multipoint buses presenting loads as low as

30Ω and incorporates controlled transition times to

allow for stubs off of the backplane transmission line.

The M-LVDS standard defines two types of receivers,

designated as Type-1 and Type-2. Type-1 receivers

have thresholds centered about zero with 25mV of

hysteresis to prevent output oscillations with loss

of input; Type-2 receivers implement a failsafe by

using an offset threshold. The xFSEN pins is used

to select the Type-1 and Type-2 receiver for each

of the channels. In addition, the driver rise and fall

times are between 1ns and 2ns, complying with the

M-LVDS standard to provide operation at 250Mbps

while also accommodating stubs on the bus. Receiver

outputs are slew rate controlled to reduce EMI and

crosstalk effects associated with large current surges.

The M-LVDS standard allows for 32 nodes on the bus

providing a high-speed replacement for RS-485 where

lower common-mode can be tolerated or when higher

signaling rates are needed.

The driver logic inputs and the receiver logic outputs

are on separate pins rather than tied together as in

some transceiver designs. The drivers have separate

enables (DE) and so does the receivers ( RE). This

arrangement of separate logic inputs, logic outputs,

and enable pins allows for a listen-while-talking

operation. The devices are characterized for operation

from –40°C to 85°C.