SP3485 3.3V Low Power Half-Duplex RS-485 Transceiver with 10Mbps Data Rate Description The SP3485 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 MaxLinear SP481, SP483 and SP485 devices as well as popular industry standards. The SP3485 can meet the electrical specifications of the RS-485 and RS422 serial protocols up to 10Mbps under load. FEATURES RS-485 and RS-422 transceiver Operates from a single 3.3V supply Interoperable with 5.0V logic Driver/receiver enable -7V to +12V common-mode input voltage range Allows up to 32 transceivers on the serial bus Compatibility with industry standard 75176 pinout Driver output short-circuit protection Ordering Information - Back Page Block Diagram R RO 1 8 VCC RE 2 7 B DE 3 6 A DI 4 D 5 GND SP3485 REV 2.0.1 1/9 SP3485 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. Storage Temperature....................................-65C to 150C Maximum Junction Temperature, TJ...........................125C Power Dissipation..................................................... 600mW VCC................................................................................ 6.0V (derate 6.90mW/C above 70C) Operating Conditions Input Voltages Package Power Dissipation Logic...................................... -0.3V to 6.0V 8-pin NSOIC JA................................................. 128.4C/W Drivers................................... -0.3V to 6.0V Receivers............................................ 15V ESD Rating Output Voltages Human Body Model (HBM)........................................... 2kV Drivers................................................ 15V Receivers............................... -0.3V to 6.0V Electrical Characteristics Unless otherwise noted: TAMB = TMIN to TMAX and VCC = 3.3V 5%. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS Vcc Volts Unloaded; R = ; Figure 1 SP3485 Driver DC Characteristics Differential output voltage 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 0.2 Volts R = 27 or R = 50; Figure 1 3 Volts R = 27 or R = 50; Figure 1 Volts Applies to DE, DI, RE Volts Applies to DE, DI, RE Change in magnitude of driver differential output voltage for complimentary states Driver common mode output voltage Input high voltage 2.0 Input low voltage 0.8 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 SP3485 Driver AC Characteristics Maximum data rate 10 Mbps RE = VCC, DE = VCC Driver input to output, tPLH 17 60 ns Figures 2 & 9 Driver input to output, tPHL 17 60 ns Figures 2 & 9 Differential driver skew 2 10 ns |tDO1- tDO2|, Figures 2 and 10 Driver rise or fall time 5 20 ns From 10%-90%; Figures 3 and 10 Driver enable to output high 35 120 ns Figures 4 and 11 Driver enable to output low 30 120 ns Figures 5 and 11 Driver disable time from low 20 120 ns Figures 5 and 11 Driver disable time from high 20 120 ns Figures 4 and 11 Driver enable from shutdown to output high, tPSH 250 ns Driver enable from shutdown to output low, tPSL 250 ns CL = 50pF, RL = 500. Figures 4, 5, and 11 600 ns Notes 1 and 2 Time to shutdown, tSHDN 50 200 REV 2.0.1 2/9 SP3485 Electrical Characteristics (Continued) Unless otherwise noted: TAMB = TMIN to TMAX and VCC = 3.3V 5%. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS 0.2 Volts -7V VCM 12V SP3485 Receiver DC Characteristics Differential input threshold -0.2 Input hysteresis Output voltage HIGH 20 mV Vcc-0.4 VCM = 0V Volts VID = 200mV, -1.5mA VID = -200mV, 2.5mA Output voltage LOW 0.4 Volts Three-state (high impedance) output current 1 A 0V VO VCC; RE = VCC k -7V VCM 12V Input resistance 12 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 Short circuit current 7 SP3485 Receiver AC Characteristics Maximum data rate 10 Receiver input to output, tPLH 40 Receiver input to output, tPLH Receiver input to output, tPHL 35 Receiver input to output, tPHL Mbps RE = 0V, DE = 0V 100 ns Figures 6 and 12 70 ns TAMB = 25C, Vcc = 3.3V, Figures 6 and 12 100 ns Figures 6 and 12 70 ns TAMB = 25C, Vcc = 3.3V, Figures 6 and 12 ns tRSKEW = tRPHL- tRPLH , Figures 6 and 12 | | Differential receiver skew 4 Receiver enable to output low 10 60 ns Figures 7 and 13, S1 closed, S2 open Receiver enable to output high 10 60 ns Figures 7 and 13, S2 closed, S1 open Receiver disable from low 10 60 ns Figures 7 and 13, S1 closed, S2 open Receiver disable from high 10 60 ns Figures 7 and 13, S2 closed, S1 open Receiver enable from shutdown to output high, tPRSH 1800 ns Receiver enable from shutdown to output low, tPRSL 1800 ns 200 600 ns Notes 1 and 2 Supply current , no load 425 2000 A RE, DI = 0V or VCC ; DE = VCC Supply current , no load 300 1500 A RE = 0V, DI = 0V or VCC, DE = 0V Time to shutdown, tSHDN 50 CL = 15pF, RL = 1k. Figures 7 and 13 Power Requirements NOTES: 1. The transceivers are put into shutdown by gringing RE high and DE low simultaneously for at least 600ns. If the control inputs are in this state for less than 50ns, the device is guaranteed to not enter shutdown. If the enable inputs are held in this state for at least 600ns, the device is assured to be in shutdown. Note that the receiver and driver times increase significantly when coming out of shutdown. 2. This spec is guaranteed by design and bench characterization. REV 2.0.1 3/9 SP3485 Pin Functions Pin Name Description 1 RO Receiver output 2 RE Receiver output enable active LOW 3 DE Driver output enable active HIGH 4 DI Driver input RE 2 7 B 5 GND Ground connection DE 3 6 A 6 A Non-inverting driver output / receiver input 7 B Inverting driver output / receiver input 8 VCC R RO 1 DI 4 D 8 VCC 5 GND Positive supply SP3485 Pinout (Top View) REV 2.0.1 4/9 SP3485 Test Circuits R VOD D CL 15pF (NOTE 2) D R Vcc GENERATOR (NOTE 1) VOC Figure 1: Driver DC Test Load Circuit 50 RL OUT 54 VCC Figure 2: Driver Propagation Delay Test Circuit S1 D CL D GENERATOR (NOTE 1) 50 RL = OUT 60 OUT R L = 110 C L = 50pF (NOTE 2) GENERATOR (NOTE 1) VCC 50 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 S1 0V OR 3V R L = 110 D V ID OUT GENERATOR (NOTE 1) 50 OUT C L = 15pF (NOTE 2) C L = 50pF (NOTE 2) GENERATOR (NOTE 1) R 50 1.5V 0V Figure 5: Driver Enable and Disable Timing Circuit, Output Low S1 S3 1.5V VCC 1k -1.5V Figure 6: Receiver Propagation Delay Test Circuit VID R S2 DI = 0 or Vcc C L = 15pF (NOTE 2) GENERATOR (NOTE 1) DE = 0 or Vcc A IOSD D B 50 -7V to +12V V Figure 7: Receiver Enable and Disable Timing Circuit Figure 8: Driver Short Circuit Current Limit Test NOTES 1: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tR < 6.0ns, ZO = 50. 2: CL includes probe and stray capacitance. REV 2.0.1 5/9 SP3485 Switching Waveforms 3V INPUT 1.5V 1.5V tPLH tPHL 3V 0V VOH 0V t DO1 VOL VOH tPHL Z OUTPUT tPLH 50% 10% OUT VOM VOM 1.5V 1.5V VOM VOM Y OUTPUT IN t DO2 90% 90% 2.0V 50% 10% -2.0V VOL t TD VOM = VOH + VOL 1.5V 2 Figure 9: Driver Propagation Delay Waveforms t TD Figure 10: Driver Differential Output Delay and Transition Time Waveforms 3V 0V VOH OUTPUT HIGH OUTPUT LOW 1.5V 1.5V DE tPZH tPSH tPHZ 3V 0.25V VOM INPUT 0V VCC 0V tPZL tPSL tPLZ VCC 0.25V VOL OUTPUT Figure 12: Receiver Propagation Delay Waveforms 3V 1.5V tPRHZ 10% VOM VOM = VCC 2 S1 is open S2 is closed S3 = 1.5V 1.5V VOH tRPHL 0V Figure 11: Driver Enable and Disable Timing Waveforms 0V tRPLH VOM VOM = VOH + VOL 1.5V 2 RE 1.5V OUTPUT VOM 3V 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 REV 2.0.1 6/9 SP3485 Description The SP3485 is a member in the family of 3.3V low power halfduplex transceivers that meet the electrical specifications of the RS-485 and RS-422 serial protocols. This device is pinto-pin compatible with the MaxLinear SP481, SP483 and SP485 devices as well as popular industry standards. The SP3485 feature MaxLinear's BiCMOS process allowing low power operationwithout sacrificing performance. Driver The driver outputs of the SP3485 are differential outputs meeting the RS-485 and RS-422 standards. The typical voltage output swing with no load will be 0 volts to 3.3 Volts. With a load of 54 across the differential outputs, the drivers can maintain greater than 1.5V voltage levels. Low Power Shutdown Mode Low-power shutdown mode is initiated by bringing both RE high and DE low. In shutdown, the devices typically draw only 50nA of supply current. RE and DE can be driven simultaneously; the part is guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown. Enable times tPRZH, tPZH, tPRZL and tPZL assume the part was not in a low-power shutdown state. Enable times tPRSH, tPSH, tPRSL and tPSL assume the parts were shut down. It takes drivers and receivers longer to become enabled from low-power shutdown mode (tPRSH, tPSH, tPRSL, tPSL) than from driver/receiver-disable mode (tPRZH, tPZH, tPRZL, tPZL). The driver of the SP3485 has a driver 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 tri-state the driver outputs. The driver of the SP3485 operates up to 10Mbps. The 250mA ISC maximum limit on the driver output allows the SP3485 to withstand an infinite short circuit over the -7.0V to 12V common mode range without catastrophic damage to the IC. Receiver The SP3485 receiver has differential inputs with an input sensitivity of 200mV. Input impedance of the receiver is 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 that guarantees the receiver output will be in a HIGH state when the input is left unconnected. The receiver of the SP3485 operates up to 10Mbps. The receiver of the SP3485 has an enable control line which is active LOW. A logic LOW on RE (pin 2) will enable the differential receiver. A logic HIGH on RE (pin 2) of the SP3485 will disable the receiver. REV 2.0.1 INPUTS OUTPUTS RE DE DI B A X 1 1 0 1 X 1 0 1 0 0 X High-Z 1 0 X Shutdown 0 Table 1: Transmit Function Truth Table INPUTS OUTPUTS RE DE VA - VB RO 0 X -50mV 1 0 X -200mV 0 X X Open/Shorted 1 1 1 X High-Z 1 0 X Shutdown Table 2: Receive Function Truth Table 7/9 SP3485 Mechanical Dimensions NSOIC8 Top View Front View Side View Drawing No: Revision: REV 2.0.1 POD-00000108 A 8/9 SP3485 Ordering Information(1) Part Number Operating Temperature Range SP3485CN-L Lead-Free Package Tube 0C to 70C SP3485CN-L/TR Yes(2) SP3485EN-L -40C to 85C SP3485EN-L/TR Packaging Method 8-pin SOIC Reel Tube Reel NOTE: 1. Refer to www.exar.com/SP3485 for most up-to-date Ordering Information. 2. Visit www.exar.com for additional information on Environmental Rating. Revision History Revision Date 10/15/02 -- 06/19/12 1.0.0 Convert to Exar Format. Update ordering information and add new Figure 8 - Driver Short Circuit Current Limit Test Circuit. Remove EOL device SP3481. 06/27/16 2.0.0 Update logo. Update description paragraph on page 1. Update timing specifications in electrical characteristics table on pages 2 and 3. Add Driver and Receiver Enable from Shutdown timing information on pages 3 and 4. Update typical supply current information on page 4. Update Figures 2, 4, 6, and 8. Update Figures 11 and 13 to add shutdown timing labels. Add low power shutdown section to page 7. Update transmit and receive truth tables on page 7. Update Receiver section on page 7. 09/06/17 2.0.1 Remove GND from Differential Output Voltage min (page 2). Added maximum junction temperature, package power dissipation and ESD rating. Update to MaxLinear logo, update format and ordering information table. Corporate Headquarters: 5966 La Place Court Suite 100 Carlsbad, CA 92008 Tel.:+1 (760) 692-0711 Fax: +1 (760) 444-8598 www.maxlinear.com Description Legacy Sipex Datasheet High Performance Analog: 48720 Kato Road Fremont, CA 94538 Tel.: +1 (510) 668-7000 Fax: +1 (510) 668-7001 Email: serialtechsupport@exar.com www.exar.com The content of this document is furnished for informational use only, is subject to change without notice, and should not be construed as a commitment by MaxLinear, Inc.. MaxLinear, Inc. assumes no responsibility or liability for any errors or inaccuracies that may appear in the informational content contained in this guide. Complying with all applicable copyright laws is the responsibility of the user. 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MaxLinear, Inc. may have patents, patent applications, trademarks, copyrights, or other intellectual property rights covering subject matter in this document. Except as expressly provided in any written license agreement from MaxLinear, Inc., the furnishing of this document does not give you any license to these patents, trademarks, copyrights, or other intellectual property. Company and product names may be registered trademarks or trademarks of the respective owners with which they are associated. (c) 2012-2017 MaxLinear, Inc. All rights reserved SP3485_DS_090617 REV 2.0.1 9/9