描述 Description

The F81439A is programmable, monolithic multi-protocol transceiver device that contains RS-232 and RS-485 / RS-422 drivers and receivers. The F81439A can be reconfigured into eight operating modes including one pure RS-232(3TX/5RX), one RS-485 (1TX/1RX) driver (TX) half duplex mode, one RS-485 (1TX/1RX) receiver (RX) half duplex mode, RS-422 (1TX/1RX) full duplex mode, RS-485 (1TX/1RX) driver (TX) half duplex mode with built-in termination resistor and bias resistor, RS-422 (1TX/1RX) full duplex mode with built-in termination resistor and bias resistor, coexist RS-232 (TX/RX only) with RS-485 mode without the need for the bus switch IC and a shutdown mode which can be selected whenever you need by changing the logic state of the 3 mode selection pins. The extra charge pumps deliver true RS-232 driver output voltage from a single power supply at either 3.3V ~ 5V. The F81439A requires only four 0.1uF capacitors for the charge pump. This item converts the 5 V input power to the ±10 V (norminal) required for RS-232 output levels. The F81439A meets the EIA-232-E V0.28 specification while using a single digital 3.3V or 5 V supply and particularly suites for those applications where ±12V is not available. A slew rate control pin configures driver outputs for either high data rate or slew-controlled data rates. Slew-controlled outputs minimize the problems that caused by the reflections and ringing on long or un-terminated cables.(1)The RS-422/RS-485 receiver and transceiver feature high impedance which allow up to 256 transceivers on a shared bus. When configured in RS-485/RS-422 mode, the driver may be individually enabled into tri-state, simplifying use on shared buses or bidirectional communication. All receivers have advanced failsafe protection to prevent oscillation when inputs are un- connected by defaulting to logic high output level. No external biasing resistors are required. In RS-232 mode each receiver input has a 5KΩ pull-down to ground. Differential Receivers will default to output logic 1 if inputs are floating, shorted or open but terminated.(1)(1)

特性 Features

? 3.3V ~ 5V Single Supply Operation
? RS 232 Data Rate 1.5Mbps (Max. Load 150pF)
? Adjustable Slew Rate for Minimize EMI Error
? RS-485 Advance Failsafe on Open, Short or Terminated Lines
? No External Biasing Resistors Are Required for RS-422/485
? Robust ESD Protection: ±15kV ESD Protection (IEC 61000-4-2 Air Gap; ±8kV contact)
? Flexible 8 Operation Modes Selected by 3 Configuration Pins for F81439A
A. One set of 3T5R RS-232 EIA-232-E V.28 Drivers & Receivers
B. One Set of RS-485 Drivers (Half Duplex Configuration)
C. One Set of RS-485 Receivers (Half Duplex Configuration)
D. One set of RS-422 Driver & Receiver (Full Duplex Configuration)
E. One Set of RS-485 Drivers (Half Duplex Configuration) with built-in termination resistor and bias resistor
F. One set of RS-422 Driver & Receiver (Full Duplex Configuration) with built-in termination resistor and bias resistor
G. One set of 1T1R RS-232 to co-exist with RS-485 application without pin select IC for special usage.
H. Shutdown Mode
? Norminal ±10V Driving Output Swing for +5V lnput
? ±16.5V Receiver Input Voltage Range
? TQFN40L 5*5 Packaging
TQFN40L 5*5