DS8925 Datasheet, PDF (9/16 Pages) National Semiconductor (TI) – LocalTalk™ Dual Driver/Triple Receiver

Typical Application Information (Continued)
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Note 9: Star (*) represents the opposite input condition for a parameter.
FIGURE 13. Differential Communication, Transformer-Coupled to a Twisted-Pair Line
SINGLE +5V SUPPLY
The DS8925 is derived from the DS3691/92 which could be
configured using a single +5V supply (V_EE = 0V). This device
is not specified for this type of operation. However, the de-
vice will not be damaged if operated using a single +5V sup-
ply.
Both drivers require the −5V supply in order to meet the out-
put voltage levels specified. When the device switches from
a positive voltage to the complimentary state, it is pulled to-
ward the V_EE level. If that level is 0V, then the complimentary
state will be near 0V instead of V_EE. Thus, the output would
switch from about 4V to 0V, instead of 4V to −4V. The differ-
ential driver will meet TIA/EIA-422, but with a reduced noise
margin. The single-ended driver will not meet TIA/EIA-423
without the −5V supply.
The receivers will be functional but may suffer parametri-
cally. The inverting receiver is referenced to V_EE therefore,
the threshold may shift slightly. The inputs can still vary over
the ±10V common mode range.
Typical Performance Characteristics (Note 10)
Differential Driver Output
Voltage vs Output Current
Differential Driver Output
Voltage vs Output Current
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