SP481R/SP485R ® 1/10th Unit Load RS-485 Transceiver FEATURES ■ Allows Over 400 Transceivers On A Transmission Line (1/10th Unit Load) ■ High Impedance on Receiver Inputs (RIN = 150kΩ typical) ■ Half-Duplex Configuration Consistent With Industry Standard Pinout ■ –7V to +12V Common Mode Input Voltage Range ■ Includes Shutdown Mode (ICC < 10µA) (For SP481R Only) ■ Low Power Consumption (250mW) ■ Separate Driver and Receiver Enable Now Available in Lead Free Packaging DESCRIPTION The SP481R and SP485R are pin-to-pin equivalent with our existing SP485 product and contain enhancements such as higher ESD tolerance and 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. Each device is packaged in an 8-pin plastic DIP or 8-pin narrow SOIC package. The SP481R offers a shutdown feature via the enable pins which will reduce the supply current (ICC) below 0.5µA typical. TYPICAL APPLICATION CIRCUIT R 8 VCC RE 2 7 B DE 3 6 A 5 GND RO 1 D DI 4 SP485 Top View Date: 6/21/04 SP485R RS-485 Serial Transceiver 1 © Copyright 2004 Sipex Corporation 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 Power Dissipation 8-pin Plastic DIP...........................1000mW 8-pin Plastic N-SOIC.......................1000mW Package Derating: 8-pin Plastic DIP øJA....................................................62 °C/W 8-pin Plastic N-SOIC øJA....................................................62 °C/W ELECTRICAL CHARACTERISTICS Typically 25°C @ Vcc = +5V unless otherwise noted. MIN. LOGIC INPUTS VIL VIH LOGIC OUTPUTS VOL VOH RS-485 DRIVER DC Characteristics TTL Input Levels VIL VIH Outputs Open Circuit Voltage Differential Output Balance Common-Mode Output Output Current Short Circuit Current AC Characteristics Maximum Data Rate Output Transition Time Propagation Delay tPHL tPLH Driver Output Skew RS-485 RECEIVER DC Characteristics TTL Output Levels VOL VOH Tri-State Output Current Inputs Common Mode Range Receiver Sensitivity Input Impedance Date: 6/21/04 TYP. MAX. 0.8 Volts Volts 0.4 Volts Volts 0.8 Volts Volts 6.0 5.0 ±0.2 3.0 Volts Volts Volts Volts mA mA 2.0 2.4 2.0 1.5 28.0 ±250 5 Mbps ns 30 60 60 5 IOUT= -3.2mA IOUT= 1.0mA RL=54Ω, CL=50pF |VT| - |VT| RL=54Ω Terminated in –7V to +12V RL=54Ω Rise/fall time, 10%–90% See Figures 3 and 5 RDIFF=54Ω, CL1=CL2=100pF RDIFF=54Ω, CL1=CL2=100pF see Figure 3 and 5, tSKEW = | tDPLH - tDPHL | ns ns ns 0.4 Volts Volts µA 0.4V≤VOUT ≤2.4V; RE = VCC Volts Volts kΩ –7V ≤ VCM ≤ +12V –7V ≤ VCM ≤ +12V ±1 120 CONDITIONS 100 100 15 2.4 –7.0 UNITS +12.0 ±0.2 150 SP485R RS-485 Serial Transceiver 2 © Copyright 2004 Sipex Corporation ELECTRICAL CHARACTERISTICS Typically 25°C @ Vcc = +5V unless otherwise noted. MIN. AC Characteristics Maximum Data Rate Propagation Delay tPHL tPLH Differential Receiver Skew ENVIRONMENTAL Operating Temperature Commercial (..C..) Industrial (..E..) Storage Temperature MAX. 1 UNITS CONDITIONS Mbps 1200 1200 ns ns ns See Figures 3 and 7 RDIFF=54Ω, CL1=CL2=100pF RDIFF=54Ω, CL1=CL2=100pF | tPLH – tPHL |; RDIFF=54Ω, CL1=CL2=100pF, see Figures 3 and 7 600 ns RE = VCC, DE = 0V 40 40 500 500 ns ns 40 40 500 500 ns ns 40 40 500 500 ns ns 40 40 500 500 ns ns 60 SHUTDOWN TIMING (SP481R) Time to Shutdown 50 RS-485 Driver Enable Time Enable to Low Enable to High Disable Time Disable From Low Disable From High RS-485 Receiver Enable Time Enable to Low Enable to High Disable Time Disable From Low Disable From High POWER REQUIREMENTS Supply Voltage VCC Supply Current ICC No Load No Load Supply Current in Shutdown TYP. +4.75 +5.25 300 500 0.5 0 –40 –65 See Figures 4 and 6 CL=15pF, S1 Closed CL=15pF, S2 Closed See Figures 4 and 6 CL=15pF, S1 Closed CL=15pF, S2 Closed See Figures 2 and 8 CL=15pF, S1 Closed CL=15pF, S2 Closed See Figures 2 and 8 CL=15pF, S1 Closed CL=15pF, S2 Closed Volts 500 900 10 µA µA µA +70 +85 +150 °C °C °C RE = VCC or 0V, DE = 0V RE = VCC or 0V, DE = VCC RE = VCC, DE = OV RECEIVER INPUT GRAPH SP485R Reciever Standard SP485R Reciever +100µA +1.0mA -7V -7V -3V +6V +6V +12V +12V -60µA -0.6 mA 1/10 Unit Load Maximum Input Current versus voltage. (Shaded region) 1 Unit Load Maximum Input Current versus voltage. (Shaded region) Date: 6/21/04 -3V SP485R RS-485 Serial Transceiver 3 © Copyright 2004 Sipex Corporation TEST CIRCUITS A VOD VCC S1 CRL R 1kΩ Test Point Receiver Output R 1kΩ VOC S2 B Figure 1. Driver DC Test Load Circuit CL1 DI A Figure 2. Receiver Timing Test Load Circuit A RL Output Under Test RO B B CL2 15pF S1 500Ω VCC CL S2 Figure 4. Driver Timing Test Load #2 Circuit Figure 3. Driver/Receiver Timing Test Circuit SWITCHING WAVEFORMS +3V f = 1MHz; tR < 10ns; tF < 10ns 1.5V DI 1.5V 0V DRIVER OUTPUT B tPLH tPHL VO 1/2VO tPLH 1/2VO A tDPLH DIFFERENTIAL VO+ OUTPUT 0V VA – VB VO– tDPHL tR tF tSKEW = | tDPLH - tDPHL | Figure 5. Driver Propagation Delays Date: 6/21/04 SP485R RS-485 Serial Transceiver 4 © Copyright 2004 Sipex Corporation f = 1MHz; tR < 10ns; tF < 10ns +3V 1.5V DE 0V 1.5V tZL tLZ 5V 2.3V A, B VOL VOH A, B 2.3V 0V Output normally LOW 0.5V Output normally HIGH 0.5V tZH tHZ Figure 6. Driver Enable and Disable Times f = 1MHz; tR < 10ns; tF < 10ns V0D2+ A–B 0V VOH 1.5V RECEIVER OUT VOL 0V INPUT V0D2– 1.5V OUTPUT tPHL tPLH tSKEW = | tPHL - tPLH | Figure 7. Receiver Propagation Delays +3V RE 0V 1.5V f = 1MHz; t < 10ns; t < 10ns R F tZL 5V RECEIVER OUT VIL 1.5V 1.5V tLZ Output normally LOW 0.5V Output normally HIGH 0.5V VIH RECEIVER OUT 0V 1.5V tZH tHZ Figure 8. Receiver Enable and Disable Times Date: 6/21/04 SP485R RS-485 Serial Transceiver 5 © Copyright 2004 Sipex Corporation GENERAL 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 orignal RS-485 specification. with the two 125Ω cable termination resistors on each end. The receiver contains a 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 receiver can operate to at least 1Mbps. 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 4,000 feet. The SP485R and SP481R exceed the standard b allowing up to 400 receivers to share a bus. The receiver also contains a fail-safe feature which outputs a logic HIGH when the inputs are open as in a disconnected cable. SHUTDOWN MODE The SP481R includes a shutdown function to reduce power consumption. The shutdown is activated by simultaneously applying a logic LOW to DE and a logic HIGH to RE. While in the shutdown mode, the power supply current is typically less than 1µA. The driver outputs are disabled and are at a high impedance state determined by the receiver input impedance which should be at least 120kΩ. The receiver output is at also at high impedance during shutdow. Output leakage current when the receiver is disabled is under 1µA. DRIVERS The driver output complies with the RS-485 electrical characteristics as specified by the standard. The output swings from 0V to VCC and maintains greater than +1.5V 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 a logic LOW. The outputs during the tri-stated condition are at a 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 a the same bus. The SP485R allows over 400 transceivers on the same bus due to the high input 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 transceivers with an input impedance of at least 120kΩ in parallel along Date: 6/21/04 SP485R RS-485 Serial Transceiver 6 © Copyright 2004 Sipex Corporation PACKAGE: 8 PIN PDIP N E INDEX AREA E1 E 2 1 3 N/2 c eA eB A1 D A e A2 D1 L b2 b b3 8 PIN PDIP JEDEC MS-001 (BA) Variation A Dimensions in inches MIN - - .210 - - .115 .130 .195 .014 A1 .015 A2 b .018 .022 b2 .045 .060 .070 b3 .030 .039 .045 c .008 .010 .014 D .355 .365 .400 D1 .005 - - E .300 .310 .325 E1 .240 .250 .280 b c 8 PIN PDIP .100 BSC e eA Date: 6/21/04 NOM MAX .300 BSC eB - - .430 L .115 .130 .150 SP485R RS-485 Serial Transceiver 7 © Copyright 2004 Sipex Corporation PACKAGE: 8 PIN NSOIC D e E/2 E1 E SEE VIEW C E1/2 1 b INDEX AREA (D/2 X E1/2) Ø1 A TOP VIEW Gauge Plane L2 Seating Plane Ø1 Ø L L1 VIEW C A2 A SEATING PLANE A1 SIDE VIEW DIMENSIONS Minimum/Maximum (mm) b WITH PLATING 8 Pin NSOIC (JEDEC MS-012, AA - VARIATION) COMMON HEIGHT DIMENSION SYMBOL A A1 A2 b c D E E1 e L L1 L2 Ø Ø1 Date: 6/21/04 MIN NOM MAX 1.75 1.35 0.25 0.10 1.25 1.65 0.31 0.51 0.17 0.25 4.90 BSC 6.00 BSC 3.90 BSC 1.27 BSC 0.40 1.27 1.04 REF 0.25 BSC 0º 8º 5º 15º c BASE METAL CONTACT AREA PACKAGE: 8 PIN NSOIC SP485R RS-485 Serial Transceiver 8 © Copyright 2004 Sipex Corporation ORDERING INFORMATION Part Number Temperature Range Package Types SP481RCP ........................................................................ 0°C to +70°C ................................................................................................ 8 Pin PDIP SP481RCN ........................................................................ 0°C to +70°C ............................................................................................. 8 Pin NSOIC SP481RCN/TR .................................................................. 0°C to +70°C ............................................................................................. 8 Pin NSOIC SP481REP ..................................................................... -40°C to +85°C ................................................................................................ 8 Pin PDIP SP481REN ..................................................................... -40°C to +85°C ............................................................................................. 8 Pin NSOIC SP481REN/TR ............................................................... -40°C to +85°C ............................................................................................. 8 Pin NSOIC SP485RCP ........................................................................ 0°C to +70°C ................................................................................................ 8 Pin PDIP SP485RCN ........................................................................ 0°C to +70°C ................................................................................................ 8 Pin NOIC SP485RCN/TR .................................................................. 0°C to +70°C ................................................................................................ 8 Pin NOIC SP485REP ..................................................................... -40°C to +85°C ................................................................................................ 8 Pin PDIP SP485REN ..................................................................... -40°C to +85°C ................................................................................................ 8 Pin NOIC SP485REN/TR ............................................................... -40°C to +85°C ................................................................................................ 8 Pin NOIC Available in lead free packaging. To order add “-L” suffix to part number. Example: SP485REN/TR = standard; SP485REN-L/TR = lead free /TR = Tape and Reel Pack quantity is 2,500 for NSOIC. REVISION HISTORY DATE 6/21/04 REVISION A DESCRIPTION Added extended temp range and tape and reel part numbers. Updated packaging specs. Corporation ANALOG EXCELLENCE Sipex Corporation Headquarters and Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Date: 6/21/04 SP485R RS-485 Serial Transceiver 9 © Copyright 2004 Sipex Corporation