The MAX3480A/B are electrically isolated RS-485/422 data communication 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 sup- ply current. The MAX3480B provides a low-power shut- down 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/B typically withstand 1600VRMS (1 minute) or 2000VRMS (1 second). Their isolated inputs and outputs meet RS-485/422 specifications.
The MAX3480A and MAX3480B are electrically isolated RS‑485/RS‑422 data‑communications interfaces packaged in a 28‑pin DIP. A single +3.3 V supply powers both the logic and isolated sides, and the devices include transceivers, optocouplers, and a transformer in one package.
Key features include a high‑speed 2.5 Mbps data rate for the MAX3480A, a slew‑rate‑limited 250 kbps option for the MAX3480B, 1600 VRMS (1 min) or 2000 VRMS (1 sec) isolation, low‑power shutdown (0.2 µA), and operation over –40 °C to +85 °C. Typical applications are industrial‑control networks, HVAC, and test equipment.
| Supply Voltage (VCC) | 3.0 V to 3.6 V |
|---|---|
| Maximum Data Rate (MAX3480A) | 2.5 Mbps |
| Maximum Data Rate (MAX3480B) | 0.25 Mbps |
| Isolation Voltage | 1600 VRMS (1 min) / 2000 VRMS (1 sec) |
| Quiescent Supply Current | 180 mA |
| Shutdown Supply Current (MAX3480B) | 0.2 µA |
The MAX3480A can transmit data at rates up to 2.5 Mbps.
They typically withstand 1600 VRMS for 1 minute or 2000 VRMS for 1 second.
A single +3.3 V supply powers both the logic and isolated sides of the interface.
In shutdown mode the MAX3480B consumes only about 0.2 µA.