NM485DC Series www.murata-ps.com Isolated Dual EIA-485 Driver and Receiver ELECTRICAL CHARACTERISTICS Parameter Test conditions 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 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 DX ENABLE and D inputs Typ. Max. Units 5.0 5.25 0.8 12 -60 60 12 12 -5.0 25 V V V V mA mA V V mA mA Max. Units 0.2 V V mV V V mA mA mA K -7.0 Driver Receiver EACH RECEIVER ELECTRICAL CHARACTERISTICS Parameter Test conditions High threshold differential input, VTH Low threshold differential input, VTL Input hysteresis, VT High level output voltage, VOH Low level output voltage, VOL VO=2.7V, IO=-0.4mA VO=0.5V, IO=16mA Line input current, II Min. Typ. -0.2 50 VID=200mV, IOH=-5.0mA VID=200mV, IOL=25mA Other input at 0V, VI=12V Other input at 0V, VI=-12V 1kVrms Isolation Short circuit output current, IOS Input resistance, RI DESCRIPTION RECEIVER SWITCHING CHARACTERISTICS 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. Min. 4.75 2.8 2.7 0.8 1.0 -0.8 -15 12 Parameter Test conditions Propagation delay time L to H, TPLH Propagation delay time H to L, TPHL VID=-1.5V to 1.5V, CL=15pF Min. Typ. Max. Units 70 72 155 135 ns ns Max. Units RECEIVER FUNCTION TABLE Differential inputs A-B RXOUT VID0.2V -0.2V2.7V) when the differential input lines are left open (open circuit). However, when a line termination resistor is attached, the inputs are effectively shorted together, not left floating. Since the receiver has typically 70mV of hysteresis, the output will remain in its last active state, high or low. To force the receiver output to a known state, the configuration shown in figure 7 should be used. It should be noted that this arrangement will use typically 100mW of power, for each receiver connected in this manner. The termination resistors are used to generate a DC bias, which forces the receiver into a high state, when no signal is applied. This arrangement will still allow the output to switch due to a change at the input, whilst maintaining line termination characteristics. 7 , 3" 3065 3 3# , 07 TECHNICAL NOTES ISOLATION VOLTAGE `Hi Pot Test', `Flash Tested', `Withstand Voltage', `Proof Voltage', `Dielectric Withstand Voltage' & `Isolation Test Voltage' are all terms that relate to the same thing, a test voltage, applied for a specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation. Murata Power Solutions NM485DC series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 1000Vrms for 1 second. A question commonly asked is, "What is the continuous voltage that can be applied across the part in normal operation?" For a part holding no specific agency approvals, such as the NM485DC series, both input and output should normally be maintained within SELV limits i.e. less than 42.4V peak, or 60VDC. The isolation test voltage represents a measure of immunity to transient voltages and the part should never be used as an element of a safety isolation system. The part could be expected to function correctly with several hundred volts offset applied continuously across the isolation barrier; but then the circuitry on both sides of the barrier must be regarded as operating at an unsafe voltage and further isolation/insulation systems must form a barrier between these circuits and any user-accessible circuitry according to safety standard requirements. REPEATED HIGH-VOLTAGE ISOLATION TESTING It is well known that repeated high-voltage isolation testing of a barrier component can actually degrade isolation capability, to a lesser or greater degree depending on materials, construction and environment. The NM485DC series has toroidal isolation transformers, with no additional insulation between primary and secondary windings of enameled wire. While parts can be expected to withstand several times the stated test voltage, the isolation capability does depend on the wire insulation. Any material, including this enamel (typically polyurethane) is susceptible to eventual chemical degradation when subject to very high applied voltages thus implying that the number of tests should be strictly limited. We therefore strongly advise against repeated high voltage isolation testing, but if it is absolutely required, that the voltage be reduced by 20% from specified test voltage. This consideration equally applies to agency recognized parts rated for better than functional isolation where the wire enamel insulation is always supplemented by a further insulation system of physical spacing or barriers. RoHS COMPLIANCE INFORMATION This series is compatible with RoHS soldering systems with a peak wave solder temperature of 300C for 10 seconds. The pin termination finish on this product series is Matte Tin over Nickel Preplate. The series is backward compatible with Sn/Pb soldering systems. For further information, please visit www.murata-ps.com/rohs www.murata-ps.com/support KII_NM485DC.A07 Page 5 of 6 NM485DC Series Isolated Dual EIA-485 Driver and Receiver PACKAGE SPECIFICATIONS MECHANICAL DIMENSIONS 1.28 (32.60) MAX NM485DC XYYWW 0.16 (4.10) 0.3 (7.60) MAX 0.58 (14.72) 0.02 (0.002) 0.50 (0.005) 0.1 (2.54) Weight: 5.9g All pins on a 0.1 (2.54) pitch. All dimensions are in inches (mm) 0.01 (0.25). 1.1 (27.94) PIN CONNECTIONS RECOMMENDED FOOTPRINT All dimensions are in inches (mm) 0.01 (0.25) TUBE OUTLINE DIMENSIONS Description Receiver number 1 output TTL logic No internal connection +5V supply Receiver number 2 output TTL logic Driver no.1 ENABLE Driver no.1 input TTL logic No Internal Connection Driver number 2 ENABLE Driver number 2 input TTL logic No Internal Connection Ground No Internal Connection Isolated ground Driver number 2 differential non-inverting output Driver number 2 differential inverting output Driver number 1 differential inverting output Driver number 1 differential non-inverting output Receiver number 2 differential inverting input Receiver number 2 differential non-inverting input Receiver number 1 differential non-inverting input Receiver number 1 differential inverting input Function R1OUT NC VCC R2OUT D1 ENABLE D1IN NC D2 ENABLE D2IN NC GND NC ISO GND D2Y D2Z D1Z D1Y R2B R2A R1A R1B 0.6673 (16.95) MAX Pin 1 2 3 4 5 6 7 8 9 10 11 12-15 16 17 18 19 20 21 22 23 24 0.012 (0.30) 0.008 (0.20) All dimensions are in inches (mm) 0.01 (0.25) Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. ISO 9001 and 14001 REGISTERED Tube Quantity : 15 This product is subject to the following operating requirements and the Life and Safety Critical Application Sales Policy: Refer to: http://www.murata-ps.com/requirements/ Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. (c) 2017 Murata Power Solutions, Inc. www.murata-ps.com/support KII_NM485DC.A07 Page 6 of 6 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Murata: NM485DC