MAX485 Low-Power RS-485 / RS-422 Transceiver
Low-power transceiver for RS-485 and RS-422 communication with one driver and one receiver, supporting data rates up to 2.5 Mbps over differential balanced lines.
Aliase:MAX485CPA, MAX485ESA, RS485 Transceiver, Modbus Driver
DIP-8 / SOIC-8 Top View
8 Pins
Pin-Tabelle8
| Pin | Signal / Name | Typ | Alternative Funktionen |
|---|---|---|---|
| 1 | RO | Digital | Receiver Output — TTL/CMOS logic output; HIGH when A > B by ≥200mV; connect to MCU UART RX pin |
| 2 | ~RE | Digital | Receiver Output Enable (Active Low) — tie LOW to enable receiver; HIGH disables receiver output; often tied together with DE pin for half-duplex control |
| 3 | DE | Digital | Driver Output Enable (Active High) — tie HIGH to enable RS-485 line driver; LOW disables driver (high-Z); often tied with ~RE for half-duplex direction control |
| 4 | DI | Digital | Driver Input — TTL/CMOS logic input from MCU UART TX; drives differential A/B outputs when DE is HIGH |
| 5 | GND | Ground | Ground Reference (0V) — connect to common ground of bus; add 100nF bypass cap between VCC and GND |
| 6 | A | Digital | Non-Inverting RS-485 Bus Line (A / D+) — connect to RS-485 bus line A; add 120Ω termination resistor between A and B at each end of the cable |
| 7 | B | Digital | Inverting RS-485 Bus Line (B / D-) — connect to RS-485 bus line B; A−B > +200mV = logic HIGH, A−B < −200mV = logic LOW |
| 8 | VCC | Power | Positive Supply Voltage (+5.0V DC; add 100nF bypass cap to GND near pin) |