The MAX3480EA/MAX3480EB are electrically isolated RS-485/RS-422 data-communications interfaces. The RS-485/RS-422 I/O pins are protected against ±15kV electrostatic discharge (ESD) shocks, without latchup. Transceivers, optocouplers, and a transformer are all included in one low-cost, 28-pin PDIP package. A single +3.3V supply on the logic side powers both sides of the interface. The MAX3480EB 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 160kbps. The MAX3480EA’s driver slew rate is not limited, allowing transmission rates up to 2.5Mbps. 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 MAX3480EA/MAX3480EB are guaranteed to withstand 1260VRMS (1min) or 1520VRMS (1s). Their isolated inputs and outputs meet RS-485/RS-422 specifications.
The MAX3480EA and MAX3480EB are electrically isolated RS‑485/RS‑422 data‑communication interfaces offered in a low‑cost 28‑pin PDIP package. Both devices operate from a single +3.3 V supply and integrate transceivers, optocouplers and a transformer, providing ±15 kV ESD protection and up to 1260 V RMS (1 min) or 1520 V RMS (1 s) isolation.
MAX3480EA supports unrestricted driver slew rates for data rates up to 2.5 Mbps, while MAX3480EB uses slew‑rate‑limited drivers to reduce EMI and supports up to 160 kbps. The devices feature short‑circuit current limiting and thermal‑shutdown protection, and include fail‑safe receiver inputs that output a logic high when open‑circuit.
| Supply Voltage (VCC) | +3.0 V to +3.6 V |
|---|---|
| Isolation Voltage | 1260 V RMS (1 min) / 1520 V RMS (1 s) |
| Maximum Data Rate (MAX3480EA) | 2.5 Mbps |
| Maximum Data Rate (MAX3480EB) | 160 kbps |
| ESD Protection | ±15 kV on I/O pins |
| Package | 28‑pin PDIP |
Both devices operate from a single supply voltage between +3.0 V and +3.6 V.
The drivers are short‑circuit current limited and include thermal‑shutdown circuitry that places the outputs in a high‑impedance state when overloaded.
All I/O pins are rated for ±15 kV electrostatic discharge protection.
Terminate the line at both ends with its characteristic impedance (typically 100 Ω) to minimize reflections.