SP485R

SP485R 1/10th Unit Load RS-485 Transceiver FEATURES • Allows Over 400 Transceivers On A Transmission Line (/0th Unit Load) • High Impedance on Receiver Inputs (RIN = 150kΩ typical) • Half-Duplex Configuration Consistent With Industry Standard Pinout • -7V to +2V Common Mode Input Voltage Range • Low Power Consumption (250mW) • Separate Driver and Receiver Enable DESCRIPTION The SP485R is a pin-to-pin equivalent to our existing SP485 product and offers a high receiver input impedance. The higher receiver input impedance allows for connecting over 400 transceivers on a single transmission line without degrading the RS-485 driver signal. The device is packaged in a 8-pin plastic DIP or 8-pin narrow SOIC. Figure 1. Typical Application Circuit Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309  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.......................................................................+7V Storage Temperature.......................-65˚C to +150˚C Typically 25ºC @ VCC = +5V unless otherwise noted. Power Dissipation 8-pin NSOIC.................................................000mW (ØJA = 62ºC/W) 8-pin PDIP....................................................000mW (ØJA = 62ºC/W) ELECTRICAL CHARACTERISTICS TYP. MAX. 0.8 UNITS Volts Volts 0.4 Volts Volts 6.0 Volts Volts Volts Volts mA +/-250 mA Mbps 30 60 60 5 00 00 5 ns ns ns ns RL = 54Ω Terminated in -7V to +2V RL = 54Ω, Rise/fall time, 0% to 90% See Figures 4 & 6, RDIFF = 54Ω, CL = CL2 = 00pF See Figures 4 & 6, RDIFF = 54Ω, CL = CL2 = 00pF see Figures 4 and 6, tSKEW = |tDPHL - tDPLH| RL = 54Ω, CL = 50pF |VT| - |VT| IOUT = -3.2mA IOUT = .0mA CONDITIONS PARAMETERS LOGIC INPUTS VIL VIH LOGIC OUTPUTS VOL VOH Open Circuit Voltage Differential Output Voltage Balance Common-Mode Output Output Current Short Circuit Current MIN. 2.0 2.4 RS-485 DRIVER DC Characteristics .5 5.0 +/-0.2 3.0 28.0 RS-485 DRIVER AC Characteristics Maximum Data Rate Output Transition Time Propagation Delay, tPLH Propagation Delay, tPHL Driver Output Skew RS-485 RECEIVER DC Characteristics Output Voltage Low, VOL Output Voltage High, VOH Tri-State Output Current 2.4 +/- 0.4 Volts Volts µA 0.4V ≤ VOUT ≤ 2.4V; RE = Vcc 5 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309 2 Typically 25ºC @ VCC = +5V unless otherwise noted. ELECTRICAL CHARACTERISTICS TYP. MAX. +2.0 +/-0.2 UNITS Volts Volts kΩ -7V ≤ VCM ≤ +12V -7V ≤ VCM ≤ +12V CONDITIONS PARAMETERS Common Mode Range Receiver Sensitivity Input Impedance MIN. -7.0 RS-485 RECEIVER DC Characteristics (continued) 20 50 RS-485 RECEIVER AC Characteristics Maximum Data Rate Propagation Delay; tPHL Propagation Delay; tPLH Differential Receiver Skew 60  200 200 Mbps ns ns ns See Figures 4 & 8, RDIFF = 54Ω, CL = CL2 = 00pF See Figures 4 & 8, RDIFF = 54Ω, CL = CL2 = 00pF See Figures 4 & 8, RDIFF = 54Ω, CL = CL2 = 00pF, tSKEW = |tPHL - tPLH| CL = 5pF, see Figures 5 and 7, S closed CL = 5pF, see Figures 5 and 7, S2 closed CL = 5pF, see Figures 5 and 7, S closed CL = 5pF, see Figures 5 and 7, S2 closed CL = 5pF, see Figures 3 and 9, S closed CL = 5pF, see Figures 3 and 9, S2 closed CL = 5pF, see Figures 3 and 9, S closed CL = 5pF, see Figures 3 and 9, S closed RS-485 DRIVER Enable / Disable Time Driver Enable to Output Low Driver Enable to Output High Driver Disable Time from Low Driver Disable Time from High RS-485 RECEIVER Enable / Disable Time Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable from Low Receiver Disable from High POWER REQUIREMENTS Supply Voltage VCC Supply Current ICC, No Load Supply Current ICC, No Load ENVIRONMENTAL Operating Temperature Commercial (..C..) Industrial (..E..) Storage Temperature 0 -40 -65 +70 +85 +50 ºC ºC ºC +4.75 300 500 +5.25 500 900 Volts µA µA RE = Vcc or 0V, DE = 0V RE = Vcc or 0V, DE = Vcc 40 40 40 40 500 500 500 500 ns ns ns ns 40 40 40 40 500 500 500 500 ns ns ns ns Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309 3 PIN FUNCTION Pin  - 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 - Driver Output / Receiver input Non-Inverting Pin 7 - B - Driver Output / Receiver Input Inverting Pin 8 - Vcc - Positive Supply 4.75V ≤ Vcc ≤ 5.25V RECEIVER INPUT GRAPH Standard SP485 Reciever +1.0mA SP485R Reciever +100µA -7V -3V +6V +12V -7V -3V +6V +12V -0.6mA 1 Unit Load Maximum Input Current versus voltage. (Shaded region) -60µA 1/10 Unit Load Maximum Input Current versus voltage. (Shaded region) TEST CIRCUITS A R VOD R B Figure 2. Driver DC Test Load Circuit Receiver Output VOC Test Point S1 CRL 1kΩ S2 1kΩ VCC Figure 3. Receiver Timing Test Load Circuit DI A B CL1 RL CL2 A B RO 15pF Output Under Test 500Ω CL S1 VCC S2 Figure 4. RS-485 Driver/Receiver Timing Test Figure 5. Driver Timing Test Load #2 Circuit SP485R_00_072309 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com 4 SWITCHING WAVEFORMS +3V 0V B A VO 1/2VO t DPLH t DPHL f ≥ 1MHz; t R ≤ 10ns ; t F ≤ 10ns 1.5V t PLH t PHL 1/2VO 1.5V DRIVER INPUT DRIVER OUTPUT DIFFERENTIAL VO+ 0V OUTPUT VA – VB VO– t SKEW = |t DPLH - t DPHL | tR tF Figure 6. Driver Propagation Delays DE +3V 0V 5V VOL VOH 0V f = 1MHz; t R < 10ns; t F < 10ns 1.5V t ZL 2.3V Output nor mally LOW Output nor mally HIGH 1.5V t LZ 0.5V 0.5V t HZ A, B A, B 2.3V t ZH Figure 7. Driver Enable and Disable Times A– B VOD2 + VOD2 – VOH VOL t PHL f = 1MHz; t R ≤ 10ns ; t F ≤ 10ns 0V INPUT 0V RECEIVER OUT 1.5V OUTPUT t PLH 1.5V Figure 8. Receiver Propagation Delays RE +3V 0V 5V VIL VIH 1.5V f = 1MHz; t ≤ 10ns; t ≤ 10ns R F t ZL 1.5V Output nor mally LOW Output nor mally HIGH 1.5V t LZ 0.5V 0.5V t HZ RECEIVER OUT RECEIVER OUT 0V 1.5V t ZH Figure 9. Receiver Enable and Disable Times Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309 5 DESCRIPTION The SP485R is a low power RS-485 differential transceiver. Similar to the SP485, the SP485R contains a half-duplex driver and receiver with tri-state control. However, the SP485R is intended for increased connections on a single bus compared to the original RS-485 specifcation. The RS-485 standard is ideal for multi-drop applications where one bus can contain many drivers and/or receivers.The RS-485 standard implementation allows up to 32 transceivers to be connected on to the data bus. RS-485 is also specified for driving higher speeds over long cable lengths of up to 4000 feet. The SP485R exceeds the standard by allowing up to 400 receivers to share the bus DRIVERS The driver output complies with the RS485 electrical characteristics as specified by the standard. The output swings from 0V to Vcc and maintains greater than +.5V with a 54Ω load attached between the two outputs. In adhering to the RS-485 specification, the driver outputs inherently comply with the RS-422 standard. With a load of 100Ω between the two outputs, the driver can sustain at least +2.0V. The driver contains an enable pin (DE) which tri-states the output when DE is logic LOW. The outputs during the tri-state condition are at high impedance (>100kΩ). A logic HIGH enables the driver for normal operation. The driver can operate to at least 5Mbps. RECEIVERS The SP485R receiver has differential inputs with an input sensitivity of lower than ±200mV. As mentioned above, the RS-485 specification allows up to 32 transceivers on the same bus. The SP485R allows over 400 transceivers on the same bus due to its high impedance of at least 120kΩ. This higher capacity allows more components to be attached to the same bus without degrading the signal quality. The drivers are still able to drive an equivalent 54Ω from the 320 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309 transceivers with an input impedance of at least 120kΩ in parallel along with the two 125Ω cable termination resistors on each end. The receiver contains an enable pin (RE) which enables the receiver when a logic LOW is asserted. A logic HIGH will tri-state the receiver output and the inputs will maintain at least 120kΩ impedance. The reciever can operate to at least Mbps The receiver also contains a fail-safe feature which outputs a logic HIGH when the inputs are open as in a disconnected cable. 6 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309 7 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP485R_00_072309 8 Model Temperature Range Package Types SP485RCN-L....................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC SP485RCN-L/TR................................................................. 0°C to +70°C ................................................................................................8-pin NSOIC SP485RCP-L....................................................................... 0°C to +70°C................................................................................................8-pin PDIP SP485REN-L...................................................................... -40°C to +85°C..............................................................................................8-pin NSOIC SP485REN-L/TR................................................................ -40°C to +85°C..............................................................................................8-pin NSOIC SP485REP-L...................................................................... -40°C to +85°C..............................................................................................8-pin PDIP ORDERING INFORMATION Note: /TR = Tape and Reel REVISION HISTORy DATE 06/2/04 07/23/09 REVISION -.0.0 DESCRIPTION Legacy Sipex Datasheet Convert to Exar Format. Update ordering information as a result of discontinued Lead type package options per PDN 081126-01. Remove all reference to the discontinued SP48R. 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 writting, 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 2009 EXAR Corporation Datasheet July 2009 Send your Interface technical inquiry with technical details to: uarttechsupport@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 • 50-668-707 • www.exar.com SP485R_00_072309 9