SP3494 +3.3V Low Power RS-485/RS-422 Transceiver * Operates From A Single +3.3V Supply * Interoperable With +5.0V Logic * +/-200mV Receiver Input Sensitivity * -7V to +12V Common-Mode Input Voltage Range * Allows Up To 32 transceivers On The Serial Bus * Driver/Receiver Enable Lines * 10A Low-Power Shutdown Mode * Compatibility with the MAX3486 and 75176 Industry Standard Pinout DESCRIPTION The SP3494 device is a +3.3V low power half-duplex transceiver that meets the specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compatible with the Exar SP3481 device as well as other popular industry standards. The SP3494 features the Exar BiCMOS process, allowing low power operation without sacrificing performance. The partially slew-rate limited drivers minimize EMI and reduce reflections caused by improperly terminated cables allowing error-free data transmission.The SP3494 is a half-duplex partially slew-rate limited transceiver that will deliver a data transmission rate up to 2.5Mbps. The SP3494 is equipped with a low-power shutdown mode and driver/receiver high-Z enable lines. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 ABSOLUTE MAXIMUM RATINGS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. VCC.....................................................................+6.0V Input Voltages Drivers.................................-0.3V to +6.0V Receivers.........................................+/-14V Output Voltages Drivers.............................................+/-14V Receivers............................-0.3V to +6.0V Storage Temperature.......................-65C to +150C Power Dissipation 8-pin NSOIC...................................................600mW (derate 6.90mW/C above +70C) ELECTRICAL CHARACTERISTICS TAMB = TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP3494 DRIVER DC Characteristics Differential Output Voltage GND Vcc Volts Unloaded; R = ; Figure 1 Differential Output Voltage 2 Vcc Volts With Load; R = 50 (RS-422); Figure 1 Differential Output Voltage 1.5 Vcc Volts With Load; R = 27 (RS-485); Figure 1 Change in Magnitude of Driver Differential Output Voltage for Complimentary states 0.2 Volts R = 27 or R = 50; Figure 1 Driver Common-Mode Output Voltage 3 Volts R = 27 or R = 50; Figure 1 Input High Voltage 2.0 Volts Applies to DE, DI, RE 0.8 Volts Applies to DE, DI, RE Input Current +/-10 A Applies to DE, DI, RE Driver Short Circuit Current VOUT = HIGH +/-250 mA -7V VO +12V; Figure 8 Driver Short Circuit Current VOUT = LOW +/-250 mA -7V VO +12V; Figure 8 Input Low Voltage SP3494 DRIVER AC Characteristics Maximum Data Rate 2.5 Driver Input to Output, tPLH 20 45 75 Mbps ns Figures 2 & 9 Driver Input to Output, tPHL 20 45 75 ns Figures 2 & 9 ns |tDO1- tDO2|, Figures 2 and 10 ns From 10%-90%; Figures 3 and 10 Differential Driver Skew 10 Driver Rise or Fall Time 30 70 RE = VCC, DE = VCC Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 ELECTRICAL CHARACTERISTICS TAMB = TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP3494 DRIVER AC Characteristics continued Driver Enable to Output High 52 120 ns Figures 4 and 11 Driver Enable to Output Low 60 120 ns Figures 5 and 11 Driver Disable Time from Low 40 120 ns Figures 5 and 11 Driver Disable Time from High 60 120 ns Figures 4 and 11 +0.2 Volts -7V VCM +12V SP3494 RECEIVER DC Characteristics Differential Input Threshold -0.2 Input Hysteresis 20 Output Voltage HIGH mV Vcc-0.4 VCM = 0V Volts VID = +200mV, -1.5mA Output Voltage LOW 0.4 Volts VID = -200mV, 2.5mA Three-State (High Impedance) Output Current +/-1 A 0V VO VCC; RE = VCC k -7V VCM +12V Input Current (A, B); VIN = 12V +1.0 mA DE = 0V, VCC = 0V or 3.6V, VIN = 12V Input Current (A, B); VIN = -7V -0.8 mA DE = 0V, VCC = 0V or 3.6V, VIN = -7V 60 mA 0V VCM VCC Input Resistance 12 Short Circuit Current 15 7 SP3485 RECEIVER AC Characteristics Maximum Data Rate 2.5 Receiver Input to Output, tPLH 40 70 Receiver Input to Output, tPHL 40 70 Mbps RE = 0V, DE = 0V 100 ns Figures 6 and 12 100 ns Figures 6 and 12 ns tRSKEW = |tRPHL- tRPLH|, Figures 6 and 12 Differential Receiver Skew 10 Receiver Enable to Output Low 35 60 ns Figures 7 and 13, S1 closed, S2 open Receiver Enable to Output High 35 60 ns Figures 7 and 13, S2 closed, S1 open Receiver Disable from Low 35 60 ns Figures 7 and 13, S1 closed, S2 open Receiver Disable from High 35 60 ns Figures 7 and 13, S2 closed, S1 open Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 ELECTRICAL CHARACTERISTICS TAMB = TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS 50 CONDITIONS SP3494 SHUTDOWN TIMING Time to Shutdown 75 200 ns RE = 3.3V, DE =0V Driver Enable from Shutdown to Output High 65 150 ns Figures 4 and 11 Driver Enable from Shutdown to Output Low 65 150 ns Figures 5 and 11 Receivers Enabled from Shutdown to Output High 50 200 ns Figures 7 and 13, S2 closed, S1 open Receivers Enabled from Shutdown to Output Low 50 200 ns Figures 7 and 13, S1 closed, S2 open Supply Current , No Load 1000 2000 A RE, DI = 0V or VCC ; DE = VCC Supply Current , No Load 800 1500 A RE = 0V, DI = 0V or VCC, DE = 0V 10 A DE = 0V, RE = VCC POWER REQUIREMENTS Shutdown Mode Pin Function SP3494 PIN FUNCTION Pin 1 - RO - Receiver output Pin 2 - RE - Receiver Output Enable Active LOW Pin 3 - DE - Driver Output Enable Active HIGH Pin 4 - DI - Driver Input Pin 5 - GND - Ground Connection Pin 6 - A - Non-Inverting Driver Output/Receiver Input Pin 7 - B - Inverting Driver Output/Receiver Input Pin 8 - Vcc - Positive Supply +3.3V +/-5% Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 Test Circuits V DM R L = 27 R S1 D VOD D R Vcc GENERATOR (NOTE 1) VOC OUT 50 C L = 15pF (NOTE 2) V CC V OM = VOH + VOL 1.5V 2 Figure 1. Driver DC Test Load Circuit Figure 2. Driver Propagation Delay Test Circuit S1 CL D GENERATOR (NOTE 1) 50 D RL = OUT 60 OUT R L = 110 C L = 50pF (NOTE 2) GENERATOR (NOTE 1) VCC 50 VOM = VOH + VOL 1.5V 2 C L = 15pF (NOTE 2) Figure 3. Driver Differential Output Delay and Transition Time Circuit. Figure 4. Driver Enable and Disable Timing Circuit, Output High VCC R L = 110 S1 0V OR 3V D V ID GENERATOR (NOTE 1) OUT R OUT 50 C L = 15pF (NOTE 2) C L = 50pF (NOTE 2) GENERATOR (NOTE 1) 50 1.5V VOM = VCC 2 0V Figure 6. Receiver Propagation Delay Test Circuit Figure 5. Driver Enable and Disable Timing Circuit, Output Low 1.5V S1 S3 VCC 1k -1.5V VID R DE = 0 or Vcc S2 DI = 0 or Vcc A/Y C L = 15pF (NOTE 2) GENERATOR (NOTE 1) IOSD D B/Z 100 -7V to +12V V 50 Figure 7. Receiver Enable and Disable Timing Circuit Figure 8. Driver Short Circuit Current Limit Test NOTE 1: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tR < 6.0ns, ZO = 50. NOTE 2: CL includes probe and stray capacitance. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 SWITCHING WAVEFORMS 3V 1.5V 1.5V INPUT 3V 0V VOH tPLH IN tPHL 1.5V 0V VOM VOM Y OUTPUT 1.5V t DO1 t DO2 VOL VOH tPHL Z OUTPUT tPLH OUT VOM VOM 50% 10% 90% 90% 2.0V 50% 10% -2.0V VOL t TD t TD VOM = VOH + VOL 1.5V 2 Figure 10. Driver Differential Output Delay and Transition Time Waveforms Figure 9. Driver Propagation Delay Waveforms 3V 3V 1.5V 1.5V DE INPUT 0V VOH OUTPUT HIGH OUTPUT LOW tPHZ tPZH 0V 0.25V VOM VCC 0V VCC tPZL VOM 0.25V 0V VOH OUTPUT Figure 12. Receiver Propagation Delay Waveforms 3V 1.5V tPRHZ 10% VOM VOM S1 is open S2 is closed S3 = 1.5V 1.5V tRPHL VOM = VCC 2 Figure 11. Driver Enable and Disable Timing Waveforms RE tRPLH 0V VOM = VOH + VOL 1.5V 2 3V 1.5V OUTPUT tPLZ VOL 1.5V S1 is closed S2 is open S3 = -1.5V 1.5V 1.5V RE 0V tPRZH tPRSH tPRLZ VCC 1.5V OUTPUT 1.5V VOL 0V tPRZL tPRSL 10% Figure 13. Receiver Enable and Disable Waveforms Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 DESCRIPTION The SP3494 is a +3.3V low power halfduplex transceiver that meets the electrical specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compatible with the Exar SP3481 and SP481 devices as well as popular industry standards such as the MAX3486 and the 75176. The SP3494 feature Exar's BiCMOS process allowing low power operation without sacrificing performance. The SP3494 has a partially slew rate limited driver with a data transmission rate of 2.5Mbps. Receiver Driver The receiver of the SP3494 has an enable control line which is active LOW. A logic LOW on RE (pin 2) of the SP3494 will enable the differential receiver. A logic HIGH on RE (pin 2) will disable the receiver. The receiver has differential inputs with an input sensitivity of 200mV. Input impedance of the receiver is typically 15k (12k minimum). A wide common mode range of -7V to +12V allows for large ground potential differences between systems. The receiver is equipped with a fail-safe feature which guarantees that the receiver output will be in a high state when the input is left unconnected. The receiver of the SP3494 operate up to 2.5Mbps. The driver outputs of the SP3494 are differential outputs. The typical voltage output swing with no load will be 0 volts to VCC. With worst case loading of 54 across the differential outputs, the driver can maintain greater than 1.5V voltage levels. The SP3494 is equipped with a shutdown mode. To enable the shutdown state, both the driver and receiver must be disable simultaneously. A logic LOW on DE (pin 3) and a logic HIGH on RE (pin 2) will put the SP3494 into shutdown. In shutdown, the supply current will drop to less than 10A. The SP3494 driver has an enable control line which is active HIGH. A logic HIGH on DE (pin 3) will enable the differential driver outputs. A logic LOW on the DE (pin 3) will force the driver outputs to high impedance (high-Z). The SP3494 driver will operate up to 2.5Mbps. In addition to adhering to the 250mA ISC maximum limit on the driver output, the driver output short-circuit protection will allow the device to withstand an infinite short circuit over the -7.0V to +12V common mode range without damage. INPUTS OUTPUTS RE DE DI Line Condition B A X 1 1 No Fault 0 1 X 1 0 No Fault 1 0 X 0 X X Z Z Table 1. Transmit Function Truth Table INPUTS OUTPUTS RE DE A-B R 0 0 +0.2V 1 0 0 -0.2V 0 0 0 Inputs Open 1 1 0 X Z Table 2. Receive Function Truth Table Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012 ORDERING INFORMATION Model Temperature Range Package Types SP3494CN-L........................................................................ 0C to +70C.................................................................................................8-pin NSOIC SP3494CN-L/TR.................................................................. 0C to +70C.................................................................................................8-pin NSOIC SP3494EN-L...................................................................... -40C to +85C..............................................................................................8-pin NSOIC SP3494EN-L/TR................................................................ -40C to +85C..............................................................................................8-pin NSOIC Note: /TR = Tape and Reel, -L = RoHS Packaging revision history DATE REVISION 10/15/02 -- 07/10/12 1.0.0 DESCRIPTION Legacy Sipex Datasheet Convert to Exar Format. Update ordering information and add new Figure 8 - Driver Short Circuit Current Limit Test Circuit. Remove EOL device SP3493. Notice EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized ; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Copyright 2012 EXAR Corporation Datasheet July 2012 For technical support please email Exar's Serial Technical Support group at: serialtechsupport@exar.com Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP3494_100_071012