DS485 Datasheet, PDF (6/10 Pages) National Semiconductor (TI) – Low Power RS-485/RS-422 Multipoint Transceiver

Parameter Measurement Information (Continued)
Pin Descriptions
Pin # I/O Name
1
O
RO
2
I
RE*
3
I
DE
4
I
DI
5
NA GND
6
I/O
A
7
I/O
B
8
NA
V_CC
Function
Receiver Output: If A > B by 200 mV, RO will be high; If A < B by 200 mV, RO will be low. RO will
be high also if the inputs (A and B) are open (non-terminated).
Receiver Output Enable: RO is enabled when RE* is low; RO is in TRI-STATE when RE* is high.
Driver Output Enable: The driver outputs (A and B) are enabled when DE is high; they are in
TRI-STATE when DE is low. Pins A and B also function as the receiver input pins (see below).
Driver Input: A low on DI forces A low and B high while a high on DI forces A high and B low when
the driver is enabled.
Ground
Non-inverting Driver Output and Receiver Input pin. Driver output levels conform to RS-485 signaling
levels.
Inverting Driver Output and Receiver Input pin. Driver output levels conform to RS-485 signaling
levels.
Power Supply: 4.75V ≤ V_CC ≤ 5.25V
Related National Low Power RS-485 Transceivers
Part Number
DS36C278
DS36C278T
DS36C279
DS36C279T
DS36C280
DS36C280T
Temperature
Range
0˚C to +70˚C
−40˚C to +85˚C
0˚C to +70˚C
−40˚C to +85˚C
0˚C to +70˚C
−40˚C to +85˚C
Number of
XCVRs on Bus
128
64
128
64
128
64
Comments
Ultra Low Power Transceiver
Ultra Low Power Transceiver
Auto-Sleep Mode
Auto-Sleep Mode
Adjustable Slew Rate Control
Adjustable Slew Rate Control
www.national.com
6