NM232DDC SeriesNM www.murata-ps.com IsolaIsolaIsolated Dual EIA-232-D tete 23 Transmitter and Receiver ELECTRICELECTRICAL CHARACTERISTICSAL CHARACTERISTICS Parameter Test conditions Min.. Typ. Max. Units High threshold input logic, VIH TXIN, SHUTDOWN, ENABLE 1.8 2.4 V Low threshold input logic, VIL TXIN, SHUTDOWN, ENABLE 0.8 1.3 V Input Hysteresis, VT TXIN 0.5 V Leakage Current, IL TXIN , SHUTDOWN or ENABLE = VCC 10 A Input capacitance, CIN TXIN 5.0 pF Low level output voltage, VOL IOUT = 3.2mA 0.4 V High level output voltage, VOH IOUT = -1.0mA 2.4 V Input pull up current VIN = OV 4.0 20 A VREF Current TXOUT = 3k, RXOUT = 2.2k 3.0 mA FEATURES ELECTRICAL CHARACTERISTICS - EIA-232-D RoHS compliant Parameter Test conditions Min.. Typ. Max. Units Positive going threshold, VT+ RXIN 1.8 3.0 V Single 5V supply Negative going threshold, VT- RXIN 0.6 1.2 V 50W low power shutdown Input Hysteresis, VT RXIN 0.6 V Input resistance RXIN 3.0 7.0 k TTL/CMOS Logic compatible Output voltage, VPP TXOUT, RL=3k to ISO GND 5.0 7.0 V EIA-232-D/E and CCITT V.28 compatible Output leakage current, IL SHUTDOWN=VCC, TXOUT=15V -10 10 A Output slew rate, SR RL=3k, CL=2500pF 3.0 30 V/s Dual transmitters and receivers Propagation delay, TL Logic to RS232 20 s 1.5kVrms Isolation Propagation delay, TR RS232 to logic 10 s Transmission rate RL=3k, CL=2500pF 9.6 kbps DESCRIPTION Supply voltage, VCC 4.5 5.5 V The NM232DDC is an electrically isolated dual TXIN=0.8V, TXOUT=3k, Supply current, ICC 53 mA RXIN=3.0V, RXOUT=2.2k transmitter and receiver designed to inter- face data terminal equipment (DTE) with data Shutdown current ICC SHUTDOWN=1 1.0 10 A communications equipment (DCE). The device ENABLE input current, IEN ENABLE=OV to VCC 1.0 A provides two data receive channels and two data Shutdown input current, ISHUTDOWN SHUTDOWN=OV to VCC 1.0 A 1 transmit channels. Each channel is EIA-232-D, MTTF 187 kHrs EIA-232-E and CCITT V.28 compatible at the interface boundary and TTL/CMOS compatible at TEMPERATURE CHARACTERISTICS the logic connections. No external components Parameter Min.. Typ. Max. Units are needed and a single 5V input supply powers Operating free-air temperature range 0 70 C all functions either side of the isolation boundary. Storage temperature range -55 125 C A low-power shutdown mode and high impedance state for receiver outputs is effected via two pins, ABSOLUTE MAXIMUM RATINGS SHUTDOWN and ENABLE. The device is supplied Supply voltage VCC with respect to pin 10 -0.3V to +6V in a low prole 24 pin DIL package. Input voltage to logic pins 3, 7, 8, & 11 with respect to -0.3V to pin 10 VCC+0.3V EIA-232-D input voltage, pins 17 & 18 -30V to +30V EIA-232-D input voltage, pins 19 & 20 -15V to +15V Voltages with respect to ISO GND pin 22 Positive input voltage, pins 16 & 21 +14V Negative input voltage, pin 23 -14V Short circuit on pins 19 & 20 Indenite Power dissipation 700mW NM232DDC maximum data rate 9.6kbps Lead case temperature 1.5mm from case for 10 seconds 300C ISOLATION CHARACTERISTICS Parameter Conditions Min.. Typ. Max. Units Isolation test voltage Flash tested for 1 second 1500 Vrms For full details go to 1. Calulated using MIL-HDBK-217F. www.murata-ps.com/rohs All data taken at TA=25C, VCC=5V. www.murata-ps.com/support KII NM232DD.A04 Page 1 of 5 NOT RECOMMENDEDOT RECOMMENDED FOR NEW DESIGNSNM232DDC Series Isolated Dual EIA-232-D Transmitter and Receiver APPLICATION NOTES Figure 1 The NM232DDC is an isolated interface device providing EIA-232-D compatibility. 3 065 A single supply from the logic side provides all necessary power for the device. The isolation feature allows the protective or frame ground of DTEs or DCEs to 7 be isolated from each other, eliminating ground loop currents and inherently long 5 */ noise paths. The voltage level between different ground points can be up to 5V 5 */ or 6V and this level ucuates as the power taken varies. This voltage appears, in (/% non-isolated equipment, as normal mode noise on the signals. With such high noise 3 065 levels present it is clearly very difcult with single ended signals to have reliable communication. Isolating the input from output so that one side oats relative to P GSBNF HSPVOE 5 % the other allows reliable communication in environments with considerable degrees Figure 2 of noise between equipments. Figure 1 shows a typical pcb track layout with a clear separation between the logic pin connections (pins 1-12) and the EIA-232-D connections (pins 13-24). Between 7 5 */ 5 065 the two sides of the layout is a track which can be connected to frame or equip- 4 54 *40 (/% 3 065 ment ground, this can be seen as the boundary between the logic and EIA-232-D 39% 3 065 side of the device. No other rules or speed conditions need to be applied other than 59% 1SPDFTTPS VT 5 */ 3 */ to keep the two halves separation to a maximum. 4)65%08/ 3 */ & -& An example of a DTE application circuit is shown in gure 2. The schematic is 5 065 illustrative of the way the NM232DDC may be connected to implement an isolated (/% EIA-232-D interface with a typical UART and processor bus. Precise circuitry will depend on the application and in particular the use of the control lines shown will % need to be altered to suit the situation. *TPMB UJPO PVOEBS Z The ENABLE control line (pin 11), puts the receiver output pins 1 and 12 into a high Figure 3 5 6 3 /. %% impedance state when set to a high level. The shutdown control line (pin 3) sets the device into a shutdown power mode when it is at high logic level. The maximum power drawn in shutdown mode is 50W, a low enough level for consideration in battery powered equipment. Where to use the NM232DDC The function of the NM232DDC is to provide an isolated signal path between a UART or similar device and the EIA-232-D interface D connector, providing two receivers and two transmitters which can be used in a number of handshake modes. One receiver and transmitter will normally be used for the signal lines and Figure 4 the remaining pair will act as handshake lines. Figure 3 shows simply where the device will be connected.EESFTT %FDPEFS More complicated schemes for controlled signal interchange will require two or more such devices. As the devices are self contained no external DC/DC converter & -& & -& is required. The enable line provides a means for creating a communications bus 59 */ 59 065 59 */ 59 065 where each NM232DDC can have a different logical address via a decoder. This /. %% /. %% 5 6 3 would allow one UART to talk with many EIA-232-D connected interfaces (see gure 4). 39 065 39 */ 39 065 39 */ 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 nish 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 NM232DD.A04 Page 2 of 5 35