Redes industriais max 485

MAX485 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceiver
DESCRIPTION
The MAX485 is low-power transceivers for RS-485 and RS422 communication. The IC contains one driver and one receiver. The driver slew rates of the MAX485 is not limited, allowing them to transmit up to 2.5Mbps. These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. All parts operate from a single 5V supply. Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit. The MAX485 is designed for half-duplex applications.

PIN CONFIGURATION
RO RE DE DI 1 2 3 4 8 7 6 5 VCC B A GND

D OR P PACKAGE
(Top View)

FEATURES
Low Quiescent Current: 300µA -7V to +12V Common-Mode Input Voltage Range Three-State Outputs 30ns Propagation Delays, 5ns Skew Operate from a Single 5V Supply Allows up to 32 Transceivers on the Bus Data rate: 2.5 Mbps Current-Limiting and Thermal Shutdown for Driver Overload Protection The transmitter outputs and receiver inputs are protected to ±15kV Air ESD

APPLICATION
Low-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level Translators Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks

ORDERING INFORMATION
Temperature Range Package SOP8L 0°C to +70°C DIP8L Orderable Device MAX485D Pb-Free MAX485DR MAX485P Package Qty 100Units/Tube 3000Units/R&T 25Units/Tube

April. 2007 Rev 1.1

1

MAX485
PIN DESCRIPTION
No. 1 2 Name RO RE Function Receive output: if A > B by 200mV, RO will be high; if A < B by 200mV, RO will be low. Receiver Output Enable. RO is enabled when RE is low; RO is high impedance when RE is high. Driver Output Enable. The driver outputs are enabled when DE is high. They are high impedance when DE is low. If