MAX3171

The MAX3171/MAX3173 are three-driver/three-receiver multiprotocol transceivers that operate from a single +3.3V supply. The MAX3171/MAX3173, along with the MAX3170 and MAX3172/MAX3174, form a complete software-selectable data terminal equipment (DTE) or data communications equipment (DCE) interface port that supports V.28 (RS-232) and V.10/V.11 (RS-449, V.36, EIA-530, EIA-530-A, X.21, RS-423) protocols. The MAX3171/MAX3173 transceivers carry the serial interface control signaling; the MAX3170 transceivers carry the clock and data signals. The MAX3172/ MAX3174 have an extra transceiver for applications requiring four transceivers for control signaling.

An internal charge pump and proprietary low-dropout transmitter output stage allow V.28, V.11, and V.10 compliant operation from a single +3.3V supply. A nocable mode of MAX3171/MAX3173 is entered when all mode pins (M0, M1, and M2) are pulled high or left unconnected. In nocable mode, supply current decreases to 2mA and all transmitter and receiver outputs are disabled (high impedance). Short-circuit limiting and thermal-shutdown circuits protect the drivers against excessive power dissipation. The MAX3171 features 10µs deglitching on the V.10/V.11/V.28 receiver inputs.

The MAX3173 is available for applications that do not require deglitching on the serial handshake signals. These MAX3171/MAX3173 parts require only four surface-mount capacitors for charge-pump operation in addition to supply bypassing.