MAX3480B:Complete, Isolated, 3.3V RS-485/RS-422 Data Interface

The MAX3480A/MAX3480B are electrically isolated RS-485/RS-422 data-communications interfaces. Transceivers, optocouplers, and a transformer are all included in one low-cost, 28-pin DIP package. A single +3.3V supply on the logic side powers both sides of the interface. The MAX3480B features reduced-slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 250kbps. The MAX3480A's driver slew rate is not limited, allowing transmission rates up to 2.5Mbps. These devices typically draw 180mA of quiescent supply current. The MAX3480B provides a low-power shutdown mode in which it consumes only 0.2µA. 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 MAX3480A/MAX3480B typically withstand 1600VRMS (1 minute) or 2000VRMS (1 second). Their isolated inputs and outputs meet RS-485/RS-422 specifications.

Key Features
  • Isolated Data Interface to 1600VRMS (1 minute)
  • Slew-Rate-Limited Data Transmission (MAX3480B)
  • High-Speed, Isolated, 2.5Mbps RS-485 Interface (MAX3480A)
  • -7V to +12V Common-Mode Input Voltage Range with Respect to Isolated Ground
  • Single +3.3V Supply
  • Current Limiting and Thermal Shutdown for Driver Overload Protection
  • Standard 28-Pin DIP Package
MAX3480A, MAX3480B: Pin Configuration
MAX3480A, MAX3480B: Pin Configuration
Applications/Uses
  • Automated Test Equipment (ATE)
  • HVAC/Building Control Networks
  • Industrial Control Local Area Networks
  • Isolated RS-485/RS-422 Data Interface
  • Transceivers for EMI-Sensitive Applications
DataSheet
titleDownload file
MAX3480A-MAX3480B Data SheetMAX3480A-MAX3480B.pdf
Parametrics
Part NumberTx/RxDuplexVSUPPLY
(V)
Galvanic Isolation
(±V)
ICC
(mA)
Data Rate
(kbps)
Tx ENRx ENICC (Shutdn.)
(µA)
Rx/Tx on BusRx Failsafe w/ InputsSlew Rate LimitingOper. Temp.
(°C)
Package/PinsBudgetary
Price
typmintypSee Notes
MAX3480A1Tx + 1RxHalf3.310001802500YesNo0.232OpenNo-40 to +85
0 to +70
PDIP(W)/28$19.43 @1k
MAX3480B120250128PDIP(W)/28
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX3480BCPINo Longer AvailableMAX3480BCPI+PDIP(W),;28 pin;592.6 mm²0°C to +70°CNo
MAX3480BCPI+ActivePDIP(W),;28 pin;592.6 mm²0°C to +70°CSee data sheet
MAX3480BEPINo Longer AvailableMAX3480BEPI+PDIP(W),;28 pin;592.6 mm²-40°C to +85°CNo
MAX3480BEPI+ActivePDIP(W),;28 pin;592.6 mm²-40°C to +85°CSee data sheet
MAX3480A-MAX3480B.pdf MAX3480B
MAX3480A-MAX3480B.pdf MAX3480B