KII_NM485D

NM485DC Isolated Dual EIA-485 Driver and Receiver ELECTRICAL CHARACTERISTICS Parameter Supply voltage, VCC High level input voltage, VIH Low level input voltage, VIL Common mode output voltage, VOC High level output current IOH Low level output current, IOL Common mode input voltage, VIC Differential input voltage, VID High level output current, IOH Low level output current, IOL Test conditions DX ENABLE and D inputs Min. 4.75 2.8 -7.0 Typ. 5.0 Max. 5.25 0.8 12 -60 60 ±12 ±12 -5.0 25 Units V V V V mA mA V V mA mA Driver Receiver FEATURES RoHS compliant Single 5V supply Thermal shutdown protection EIA-485 and CCITT V.28 compatible Dual differential driver and receiver Driver tri-state outputs active high enable Low Profile 24 pin DIL package style 1kVrms Isolation EACH RECEIVER ELECTRICAL CHARACTERISTICS Parameter High threshold differential input, VTH Low threshold differential input, VTL Input hysteresis, ΔVT High level output voltage, VOH Low level output voltage, VOL Line input current, II Short circuit output current, IOS Input resistance, RI Test conditions VO=2.7V, IO=-0.4mA VO=0.5V, IO=16mA VID=200mV, IOH=-5.0mA VID=200mV, IOL=25mA Other input at 0V, VI=12V Other input at 0V, VI=-12V Min. -0.2 Typ. Max. 0.2 Units V V mV V V mA mA mA KΩ 50 2.7 0.8 1.0 -0.8 -15 12 DESCRIPTION The NM485DC is an electrically isolated dual differential driver and receiver designed for balanced mulipoint bus transmission at rates up to 1.25Mbits per second. The device provides two receive channels and two driver channels. The two driver channels have an active high enable. No external components are needed and a single 5V input supply powers all functions either side of the isolation boundary. The driver outputs provide limiting for positive and negative currents and thermal shutdown protection from line fault conditions on the transmission bus line. The receiver outputs will always be high if the receiver inputs are open. The isolation voltage between input and output is 1000Vrms, the devices are supplied in a low profile 24 pin DIL plastic package. RECEIVER SWITCHING CHARACTERISTICS Parameter Propagation delay time L to H, TPLH Propagation delay time H to L, TPHL Test conditions VID=-1.5V to 1.5V, CL=15pF Min. Typ. 70 72 Max. 155 135 Units ns ns RECEIVER FUNCTION TABLE Differential inputs A-B VID≥0.2V -0.2V