The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E are low-power transceivers for RS-485 and RS-422 communications in harsh environments. Each driver output and receiver input is protected against ±15kV electrostatic discharge (ESD) shocks, without latchup. These parts contain one driver and one receiver. The MAX483E, MAX487E, MAX488E, and MAX489E feature reduced slewrate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, thus allowing error-free data transmission up to 250kbps. The driver slew rates of the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E are not limited, allowing them to transmit up to 2.5Mbps. These transceivers draw as little as 120μA supply current when unloaded or when fully loaded with disabled drivers (see Selection Table). Additionally, the MAX481E, MAX483E, and MAX487E have a low-current shutdown mode in which they consume only 0.5μA. 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 their 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 MAX487E and MAX1487E feature quarter-unit-load receiver input impedance, allowing up to 128 transceivers on the bus. The MAX488E–MAX491E are designed for fullduplex communications, while the MAX481E, MAX483E, MAX485E, MAX487E, and MAX1487E are designed for halfduplex applications. For applications that are not ESD sensitive see the pin- and function-compatible MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487.
Features:
© ESD Protection: ±15kV—Human Body Model
© Slew-Rate Limited for Error-Free Data
Transmission (MAX483E/487E/488E/489E)
© Low Quiescent Current:
120μA (MAX483E/487E/488E/489E)
230μA (MAX1487E)
300μA (MAX481E/485E/490E/491E)
© -7V to +12V Common-Mode Input Voltage Range
© Three-State Outputs
© 30ns Propagation Delays, 5ns Skew
(MAX481E/485E/490E/491E/1487E)
© Full-Duplex and Half-Duplex Versions Available
© Allows up to 128 Transceivers on the Bus
(MAX487E/MAX1487E)
© Current Limiting and Thermal Shutdown for
Driver Overload Protection
Applications:
Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Feature
- Low Power Consumption Minimizes Thermal Dissipation, Reducing System Cost
- 120μA to 500μA Quiescent Current
- Shutdown Current of 0.1μA
- Single 5V Supply Voltage
- Slew-Rate-Limited Drivers (MAX483/MAX487/MAX488 and MAX489)
- Up to 250kbps Data Rate
- Unlimited Drivers: Up to 2.5Mbps Data Rate
- Integrated Protection Enhances System Robustness
- Short Circuit Current Limited Driver
- Integrated Thermal Shutdown
- Receiver Fail-Safe for Input Open Circuit
- Guarantees Logic High
- 1/4 Unit Loading (MAX487/ MAX1487 only) Allows Up to 128 Devices on a Single Bus
- 48kΩ Receiver Input Resistance
Applications
- Industrial-Control Local Area Networks
- Level Translators
- Low-Power RS-422 Transceivers
- Low-Power RS-485 Transceivers
- Transceivers for EMI-Sensitive Applications
(Picture: Pinout)
