FEATURES

· Low-Voltage Differential 30-W to 55-W Line

Drivers and Receivers for Signaling Rates (1)

Up to 250 Mbps; Clock Frequencies Up to

125 MHz

· Meets or Exceeds the M-LVDS Standard

TIA/EIA-899 for Multipoint Data Interchange

· Controlled Driver Output Voltage Transition

Times for Improved Signal Quality

· –1 V to 3.4 V Common-Mode Voltage Range

Allows Data Transfer With 2 V of Ground

Noise

· Bus Pins High Impedance When Driver

Disabled or V CC £ 1.5 V

· Independent Enables for each Driver

· Bus Pin ESD Protection Exceeds 8 kV

· Packaged in 64-Pin TSSOP (DGG)

· M-LVDS Bus Power Up/Down Glitch Free

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

DESCRIPTION

The SN65MLVD080 and SN65MLVD082 provide

eight 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 250 Mbps. The driver outputs have been

designed to support multipoint buses presenting

loads as low as 30-W and incorporates controlled

transition times to allow for stubs off of the backbone

transmission line.

The M-LVDS standard defines two types of receivers,

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

(SN65MLVD080) have thresholds centered about

zero with 25 mV of hysteresis to prevent output

oscillations with loss of input; Type-2 receivers

(SN65MLVD082) implement a failsafe by using an

offset threshold. In addition, the driver rise and fall

times are between 1 and 2.0 ns, complying with the

M-LVDS standard to provide operation at 250 Mbps

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 the receivers are enabled globally

through (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.