Datasheet

MAX13487E/MAX13488E
Half-Duplex RS-485-/RS-422-Compatible
Transceiver with AutoDirection Control
______________________________________________________________________________________ 11
Pin Description
PIN NAME FUNCTION
1RO
Receiver Output. When receiver is enabled and V(A) - V(B) > +200mV, RO is high. If V(A) - V(B)
< -200mV, RO is low.
2 RE
Receiver Output Enable. Drive RE low to enable the RO. Drive RE high to let the AutoDirection circuit
control the receiver. RE is a hot-swap input (see the Hot-Swap Capability section for more details).
3 SHDN
Shutdown. Drive SHDN high to let the device operate in normal operation. Drive SHDN low to put the part
in shutdown.
4DI
Driver Input. Drive DI low to force noninverting output low and inverting output high. Drive DI high to force
noninverting output high and inverting output low. DI is an input to the internal state machine that
automatically enables and disables the driver. See the Function Tables and General Description for more
information. DI is a hot-swap input (see the Hot-Swap Capability section for more details).
5 GND Ground
6 A Noninverting Receiver Input and Noninverting Driver Output
7 B Inverting Receiver Input and Inverting Driver Output
8V
CC
Positive Supply, V
CC
= +5V ±5%. Bypass V
CC
to GND with a 0.1µF capacitor.
TRANSMITTING
INPUTS OUTPUTS
SHDN DI A-B > V
DT
ACTION A B
1 0 X Turn driver ON 0 1
1 1 False If driver was OFF, keep it OFF HIGH IMPEDANCE HIGH IMPEDANCE
1 1 False If driver was ON, keep it ON 1 0
1 1 True Turn driver OFF HIGH IMPEDANCE HIGH IMPEDANCE
0 X X X SHUTDOWN
RECEIVING
INPUTS OUTPUT
SHDN RE A-B DRIVER STATE RECEIVER STATE RO
10≥+200mV X ON 1
10≤-200mV X ON 0
1 1 X ON OFF HIGH IMPEDANCE
11≥+200mV OFF ON 1
11≤-200mV OFF ON 0
0 X X X X SHUTDOWN
Function Tables
X = Don’t care, shutdown mode, driver, and receiver outputs are in high impedance.