Fault Protected, Extended CMR, RS-485/RS-422 Transceivers with Cable Invert and ±16.5kV ESD ISL32483E, ISL32485E The ISL3248xE are fault protected, 5V powered differential transceivers that exceed the RS-485 and RS-422 standards for balanced communication. The RS-485 transceiver pins (driver outputs and receiver inputs) are fault protected up to ±60V and are protected against ±16.5kV ESD strikes without latch-up. Additionally, the extended common mode range allows these transceivers to operate in environments with common mode voltages up to ±25V (>2X the RS-485 requirement), making this fault-protected RS-485 family one of the most robust on the market. Transmitters (Tx) deliver an exceptional 2.5V (typical) differential output voltage into the RS-485 specified 54Ω load. This yields better noise immunity than standard RS-485 ICs or allows up to six 120Ω terminations in star network topologies. Receiver (Rx) inputs feature a “Full Fail-Safe” design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or on a terminated but undriven (idle) bus. The ISL32483E and ISL32485E include cable invert functions that reverse the polarity of the Rx and/or Tx bus pins in case the cable is misconnected. Unlike competing devices, Rx full fail-safe operation is maintained even when the Rx input polarity is switched. For fault protected RS-485 transceivers without the cable invert function, please see the ISL32470E and ISL32490E data sheets. 30 VOLTAGE (V) Applications • Utility Meters/Automated Meter Reading Systems • High Node Count RS-485 Systems • PROFIBUS® and RS-485 Based Field Bus Networks, and Factory Automation • Security Camera Networks • Building Lighting and Environmental Control Systems • Industrial/Process Control Networks 25 COMMON MODE RANGE A 20 15 10 5 RO 0 12 0 -7 -12 -20 -25 -5 STANDARD RS-485 TRANSCEIVER TIME (400ns/DIV) FIGURE 1. EXCEPTIONAL Rx OPERATES AT 1Mbps EVEN WITH ±25V COMMON MODE VOLTAGE January 18, 2011 FN7785.0 • Fault Protected RS-485 Bus Pins . . . . . . . . . . . . . . Up to ±60V • Extended Common Mode Range . . . . . . . . . . . . . . . . . . . ±25V More Than Twice the Range Required for RS-485 • ±16.5kV HBM ESD Protection on RS-485 Bus Pins • Cable Invert Pins Corrects for Reversed Cable Connections While Maintaining Rx Full Fail-Safe Functionality • Full Fail-Safe (Open, Short, Terminated) RS-485 Receivers • 1/4 Unit Load (UL) for Up to 128 Devices on the Bus • High Rx IOL for Opto-Couplers in Isolated Designs • Hot Plug Circuitry: Tx and Rx Outputs Remain Three-State During Power-up/Power-down • Slew Rate Limited RS-485 Data Rate . . . . . . . . . . . . . 1Mbps • Low Quiescent Supply Current . . . . . . . . . . . . . . . . . . . 2.3mA • Ultra Low Shutdown Supply Current . . . . . . . . . . . . . . . 10µA VID = ±1V B 25 Features 1 CLOSEST COMPETITOR ISL3248XE FIGURE 2. TRANSCEIVERS DELIVER SUPERIOR COMMON MODE RANGE vs STANDARD RS-485 DEVICES CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas Inc. 2011. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. ISL32483E, ISL32485E TABLE 1. SUMMARY OF FEATURES HALF/FULL DUPLEX PART NUMBER DATA RATE (Mbps) SLEW-RATE LIMITED? EN PINS? HOT PLUG POLARITY REVERSAL PINS? QUIESCENT ICC (mA) LOW POWER SHDN? PIN COUNT ISL32483E Full 1 Yes Yes Yes Yes 2.3 Yes 14 ISL32485E Half 1 Yes Tx Only Yes Yes 2.3 No 8 Ordering Information PART NUMBER (Notes 1, 2, 3) PART MARKING TEMP. RANGE (°C) PACKAGE (Pb-Free) PKG. DWG. # ISL32483EIBZ ISL32483 EIBZ -40 to +85 14 Ld SOIC M14.15 ISL32485EIBZ 32485 EIBZ -40 to +85 8 Ld SOIC M8.15 NOTES: 1. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications. 2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL32483E and ISL32485E. For more information on MSL please see techbrief TB363. Pin Configurations ISL32485E (8 LD SOIC) TOP VIEW ISL32483E (14 LD SOIC) TOP VIEW RINV 1 14 VCC RO 1 R 8 VCC 13 VCC INV 2 7 B/Z RE 3 12 A DE 3 6 A/Y DE 4 11 B DI 4 5 GND RO 2 DI 5 R D 10 Z GND 6 9 Y GND 7 8 DINV 2 D FN7785.0 January 18, 2011 ISL32483E, ISL32485E Pin Descriptions PIN NAME ISL32483E PIN # ISL32485E PIN # RO 2 1 RE 3 N/A DE 4 3 Driver output enable. The driver outputs, Y and Z, are enabled by bringing DE high, and they are high impedance when DE is low. Internally pulled high to VCC. DI 5 4 Driver input. If INV or DINV is low, a low on DI forces output Y low and output Z high, while a high on DI forces output Y high and output Z low. The output states relative to DI invert if INV or DINV is high. GND 6, 7 5 Ground connection. A/Y N/A 6 ±60V Fault and ±16.5kV HBM ESD Protected RS-485/RS-422 level I/O pin. If INV is low, A/Y is the non-inverting receiver input and non-inverting driver output. If INV is high, A/Y is the inverting receiver input and the inverting driver output. Pin is an input if DE = 0; pin is an output if DE = 1. B/Z N/A 7 ±60V Fault and ±16.5kV HBM ESD Protected RS-485/RS-422 level I/O pin. If INV is low, B/Z is the inverting receiver input and inverting driver output. If INV is high, B/Z is the non-inverting receiver input and the non-inverting driver output. Pin is an input if DE = 0; pin is an output if DE = 1. A 12 N/A ±60V Fault and ±15kV HBM ESD Protected RS-485/RS-422 level input. If RINV is low, then A is the non-inverting receiver input. If RINV is high, then A is the inverting receiver input. B 11 N/A ±60V Fault and ±15kV HBM ESD Protected RS-485/RS-422 level input. If RINV is low, then B is the inverting receiver input. If RINV is high, then B is the non-inverting receiver input. Y 9 N/A ±60V Fault and ±15kV HBM ESD Protected RS-485/RS-422 level output. If DINV is low, then Y is the non-inverting driver output. If DINV is high, then Y is the inverting driver output Z 10 N/A ±60V Fault and ±15kV HBM ESD Protected RS-485/RS-422 level. If DINV is low, then Z is the inverting driver output. If DINV is high, then Z is the non-inverting driver output VCC 13, 14 8 System power supply input (4.5V to 5.5V). INV N/A 2 Receiver and driver polarity selection input. When driven high, this pin swaps the polarity of the driver output and receiver input pins. If unconnected (floating) or connected low, normal RS-485 polarity conventions apply. Internally pulled low. RINV 1 N/A Receiver polarity selection input. When driven high, this pin swaps the polarity of the receiver input pins. If unconnected (floating) or connected low, normal RS-485 polarity conventions apply. Internally pulled low. DINV 8 N/A Driver polarity selection input. When driven high, this pin swaps the polarity of the driver output pins. If unconnected (floating) or connected low, normal RS-485 polarity conventions apply. Internally pulled low. 3 FUNCTION Receiver output. If INV or RINV is low, then: If A - B ≥ -10mV, RO is high; if A - B ≤ -200mV, RO is low. If INV or RINV is high, then: If B - A ≥ -10mV, RO is high; if B - A ≤ -200mV, RO is low. In all cases, RO = High if A and B are unconnected (floating), or shorted together, or connected to an undriven, terminated bus (i.e., Rx is always failsafe open, shorted, and idle, even if polarity is inverted). Receiver output enable. RO is enabled when RE is low; RO is high impedance when RE is high. Internally pulled low. FN7785.0 January 18, 2011 ISL32483E, ISL32485E Truth Tables RECEIVING INPUTS TRANSMITTING OUTPUT RE DE (Half Duplex) DE (Full Duplex) A-B INV or RINV RO 0 0 X ≥ -0.01V 0 1 0 0 X ≤ -0.2V 0 0 0 0 X ≤ 0.01V 1 1 0 0 X ≥ 0.2V 1 0 0 0 X X 1 High-Z High-Z (see Note) (see Note) Inputs Open or Shorted 1 0 0 X X NOTE: Low Power Shutdown Mode (see Note 11 on page 7), except for ISL32485E. High-Z (see Note) 1 1 1 X X High-Z INPUTS OUTPUTS RE DE DI INV or DINV Y Z X 1 1 0 1 0 X 1 0 0 0 1 X 1 1 1 0 1 X 1 0 1 1 0 0 0 X X High-Z High-Z 1 0 X X NOTE: Low Power Shutdown Mode (see Note 11 on page 7), except for ISL32485E. Typical Operating Circuits +5V +5V + 13, 14 1 RINV 2 RO VCC R B 11 0.1µF 0.1µF RT + 13, 14 VCC 9 Y A 12 D 10 Z DI 5 3 RE DE 4 4 DE RE 3 5 DI 8 RT Y 9 Z 10 D DINV 11 B 12 A GND GND R RO 2 RINV DINV 1 8 6, 7 6, 7 THE IC ON THE LEFT HAS THE CABLE CONNECTIONS SWAPPED, SO THE INV PINS (1, 8) ARE STRAPPED HIGH TO INVERT ITS RX AND TX POLARITY ISL34183E FULL DUPLEX EXAMPLE 4 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Absolute Maximum Ratings Thermal Information VCC to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V Input Voltages DI, INV, RINV, DINV, DE, RE. . . . . . . . . . . . . . . . . . . . -0.3V to (VCC + 0.3V) Input/Output Voltages A/Y, B/Z, A, B, Y, Z. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±60V A/Y, B/Z, A, B, Y, Z (Transient Pulse Through 100Ω, see Note 15). . . . . . . . . . . . . . . . . ±80V RO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to (VCC +0.3V) Short Circuit Duration Y, Z. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indefinite ESD Rating . . . . . . . . . . . . . . . . . . . . see “ESD PERFORMANCE” on page 6 Latch-up (Tested per JESD78, Level 2, Class A). . . . . . . . . . . . . . . . +125°C Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W) 8 Ld SOIC Package (Notes 4, 5). . . . . . . . . . 116 47 14 Ld SOIC Package (Notes 4, 5) . . . . . . . . 88 39 Maximum Junction Temperature (Plastic Package) . . . . . . . . . . . . +150°C Maximum Storage Temperature Range . . . . . . . . . . . . . . -65°C to +150°C Pb-free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Supply Voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C Bus Pin Common Mode Voltage Range . . . . . . . . . . . . . . . . . -25V to +25V CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTES: 4. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 5. For θJC, the “case temp” location is taken at the package top center. Electrical Specifications Test Conditions: VCC = 4.5V to 5.5V; Unless Otherwise Specified. Typicals are at VCC = 5V, TA = +25°C (Note 6). Boldface limits apply over the operating temperature range, -40°C to +85°C. PARAMETER SYMBOL TEST CONDITIONS TEMP (°C) MIN (Note 14) TYP MAX (Note 14) UNITS Full - - VCC V DC CHARACTERISTICS Driver Differential VOUT (No load) VOD1 Driver Differential VOUT (Loaded, Figure 3A) VOD2 RL = 100Ω (RS-422) Full 2.4 3.2 - V RL = 54Ω (RS-485) Full 1.5 2.5 VCC V RL = 54Ω (PROFIBUS, VCC ≥ 5V) Full 2.0 2.5 - V RL = 21Ω (Six 120Ω terminations for Star Configurations, VCC ≥ 4.75V) Full 0.8 1.3 - V Change in Magnitude of Driver Differential VOUT for Complementary Output States ΔVOD RL = 54Ω or 100Ω (Figure 3A) Full - - 0.2 V Driver Differential VOUT with Common Mode Load (Figure 3B) VOD3 RL = 60Ω, -7V ≤ VCM ≤ 12V Full 1.5 2.1 VCC V RL = 60Ω, -25V ≤ VCM ≤ 25V (VCC ≥ 4.75V) Full 1.7 2.3 RL = 21Ω, -15V ≤ VCM ≤ 15V (VCC ≥ 4.75V) Full 0.8 1.1 - V Driver Common-Mode VOUT (Figure 3) VOC Change in Magnitude of Driver Common-Mode VOUT for Complementary Output States Driver Short-Circuit Current V RL = 54Ω or 100Ω Full -1 - 3 V RL = 60Ω or 100Ω, -20V ≤ VCM ≤ 20V Full -2.5 - 5 V DVOC RL = 54Ω or 100Ω (Figure 3A) Full - - 0.2 V - 250 mA 83 mA IOSD DE = VCC, -25V ≤ VO ≤ 25V (Note 8) Full -250 IOSD1 At First Fold-back, 22V ≤ VO ≤ -22V Full -83 IOSD2 At Second Fold-back, 35V ≤ VO ≤ -35V Full -13 VIH DE, DI, RE, INV, RINV, DINV Full 2.5 Logic Input Low Voltage VIL DE, DI, RE, INV, RINV, DINV Full Logic Input Current IIN1 DI Full DE, RE, INV, RINV, DINV Full -15 Logic Input High Voltage 5 13 mA - - V - - 0.8 V -1 - 1 µA 6 15 µA FN7785.0 January 18, 2011 ISL32483E, ISL32485E Electrical Specifications Test Conditions: VCC = 4.5V to 5.5V; Unless Otherwise Specified. Typicals are at VCC = 5V, TA = +25°C (Note 6). Boldface limits apply over the operating temperature range, -40°C to +85°C. (Continued) PARAMETER SYMBOL Input/Output Current (A/Y, B/Z) IIN2 Input Current (A, B) (Full Duplex Versions Only) Output Leakage Current (Y, Z) (Full Duplex Versions Only) IIN3 IOZD Receiver Differential Threshold Voltage V TH TEST CONDITIONS DE = 0V, VCC = 0V or 5.5V VCC = 0V or 5.5V TEMP (°C) MIN (Note 14) TYP MAX (Note 14) UNITS VIN = 12V Full - 110 250 µA VIN = -7V Full -200 -75 - µA VIN = ±25V Full -800 ±240 800 µA VIN = ±60V (Note 17) Full -6 ±0.7 6 mA VIN = 12V Full - 90 125 µA VIN = -7V Full -100 -70 - µA VIN = ±25V Full -500 ±200 500 µA VIN = ±60V (Note 17) Full -3 ±0.5 3 mA VIN = 12V Full - 20 200 µA VIN = -7V Full -100 -5 - µA VIN = ±25V Full -500 ±40 500 µA VIN = ±60V (Note 17) Full -3 ±0.15 3 mA A-B if INV or RINV = 0; B-A if INV or RINV = 1, -25V ≤ VCM ≤ 25V Full -200 -100 -10 mV 25 - 25 - mV IO = -2mA Full VCC - 0.5 4.75 - V IO = -8mA Full 2.8 4.2 - V RE = 0V, DE = 0V, VCC = 0V or 5.5V Receiver Input Hysteresis DV TH -25V ≤ VCM ≤ 25V Receiver Output High Voltage VOH VID = -10mV Receiver Output Low Voltage VOL IO = 6mA, VID = -200mV Full - 0.27 0.4 V Receiver Output Low Current IOL VO = 1V, VID = -200mV Full 15 22 - mA Three-State (High Impedance) Receiver Output Current IOZR 0V ≤ VO ≤ VCC (Note 16) Full -1 0.01 1 µA Receiver Short-Circuit Current IOSR 0V ≤ VO ≤ VCC Full ±12 - ±110 mA DE = VCC, RE = 0V or VCC, DI = 0V or VCC Full - 2.3 4.5 mA DE = 0V, RE = VCC, DI = 0V or VCC (Note 16) Full - 10 50 µA 1/2 Duplex 25 - ±16.5 - kV Full Duplex 25 - ±15 - kV SUPPLY CURRENT No-Load Supply Current (Note 7) Shutdown Supply Current ICC ISHDN ESD PERFORMANCE RS-485 Pins (A, Y, B, Z, A/Y, B/Z) Human Body Model, From Bus Pins to GND All Pins Human Body Model, per JEDEC 25 - ±8 - kV Machine Model 25 - ±700 - V - 70 125 ns DRIVER SWITCHING CHARACTERISTICS Driver Differential Output Delay tPLH, tPHL RD = 54Ω, CD = 50pF No CM Load (Figure 4) -25V ≤ VCM ≤ 25V Full Full - - 350 ns Driver Differential Output Skew tSKEW RD = 54Ω, CD = 50pF No CM Load (Figure 4) -25V ≤ VCM ≤ 25V Full - 4.5 15 ns Full - - 25 ns Driver Differential Rise or Fall Time tR, tF RD = 54Ω, CD = 50pF No CM Load (Figure 4) -25V ≤ VCM ≤ 25V Full 70 170 300 ns Full 70 - 400 ns Maximum Data Rate fMAX CD = 820pF (Figure 6) Full 1 4 - Mbps Driver Enable to Output High tZH SW = GND (Figure 5), (Note 9) Full - - 350 ns Driver Enable to Output Low tZL SW = VCC (Figure 5), (Note 9) Full - - 300 ns Driver Disable from Output Low tLZ SW = VCC (Figure 5) Full - - 120 ns 6 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Electrical Specifications Test Conditions: VCC = 4.5V to 5.5V; Unless Otherwise Specified. Typicals are at VCC = 5V, TA = +25°C (Note 6). Boldface limits apply over the operating temperature range, -40°C to +85°C. (Continued) PARAMETER Driver Disable from Output High Time to Shutdown TEMP (°C) MIN (Note 14) TYP MAX (Note 14) UNITS SW = GND (Figure 5) Full - - 120 ns SYMBOL tHZ tSHDN TEST CONDITIONS (Notes 11, 16) Full 60 160 600 ns Driver Enable from Shutdown to Output High tZH(SHDN) SW = GND (Figure 5), (Notes 11, 12, 16) Full - - 2000 ns Driver Enable from Shutdown to Output Low tZL(SHDN) SW = VCC (Figure 5), (Notes 11, 12, 16) Full - - 2000 ns RECEIVER SWITCHING CHARACTERISTICS fMAX -25V ≤ VCM ≤ 25V (Figure 7) Full 1 15 - Mbps Receiver Input to Output Delay Maximum Data Rate tPLH, tPHL -25V ≤ VCM ≤ 25V (Figure 7) Full - 90 150 ns Receiver Skew | tPLH - tPHL | tSKD (Figure 7) Full - 4 10 ns Receiver Enable to Output Low tZL RL = 1kΩ, CL = 15pF, SW = VCC (Figure 8), (Notes 10, 16) Full - - 50 ns Receiver Enable to Output High tZH RL = 1kΩ, CL = 15pF, SW = GND (Figure 8), (Notes 10, 16) Full - - 50 ns Receiver Disable from Output Low tLZ RL = 1kΩ, CL = 15pF, SW = VCC (Figure 8) (Note 16) Full - - 50 ns Receiver Disable from Output High tHZ RL = 1kΩ, CL = 15pF, SW = GND (Figure 8) (Note 16) Full - - 50 ns (Notes 11, 16) Full 60 160 600 ns Time to Shutdown tSHDN Receiver Enable from Shutdown to Output High tZH(SHDN) RL = 1kΩ, CL = 15pF, SW = GND (Figure 8), (Notes 11, 13, 16) Full - - 2000 ns Receiver Enable from Shutdown to Output Low tZL(SHDN) RL = 1kΩ, CL = 15pF, SW = VCC (Figure 8), (Notes 11, 13, 16) Full - - 2000 ns NOTES: 6. All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. 7. Supply current specification is valid for loaded drivers when DE = 0V. 8. Applies to peak current. See “Typical Performance Curves” beginning on page 18 for more information 9. Keep RE = 0 to prevent the device from entering SHDN. 10. The RE signal high time must be short enough (typically <100ns) to prevent the device from entering SHDN. 11. Transceivers (except on the ISL32485E) are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 60ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See “Low Power Shutdown Mode” on page 12. 12. Keep RE = VCC, and set the DE signal low time >600ns to ensure that the device enters SHDN. 13. Set the RE signal high time >600ns to ensure that the device enters SHDN. 14. Compliance to data sheet limits is assured by one or more methods: production test, characterization and/or design. 15. Tested according to TIA/EIA-485-A, Section 4.2.6 (±80V for 15ms at a 1% duty cycle). 16. Does not apply to the ISL32485E. The ISL32485E has no Rx enable function, and thus no SHDN function. 17. See “Caution” statement in the “Recommended Operating Conditions” section on page 5. 7 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Test Circuits and Waveforms RL/2 DE VCC VCC Z DI Z DI VOD D VCM VOD D Y Y VOC VOC RL/2 375Ω RL/2 DE RL/2 FIGURE 3A. VOD AND VOC 375Ω FIGURE 3B. VOD AND VOC WITH COMMON MODE LOAD FIGURE 3. DC DRIVER TEST CIRCUITS 3V DI 50% 50% 0V VCC 375Ω* DE tPLH Z DI CD D VOH OUT (Y) VOL RD Y SIGNAL GENERATOR tPHL OUT (Z) VCM 375Ω* *ONLY USED FOR COMMON MODE LOAD TESTS 90% DIFF OUT (Y - Z) +VOD 90% 10% 10% tR -VOD tF SKEW = |tPLH - tPHL| FIGURE 4A. TEST CIRCUIT FIGURE 4B. MEASUREMENT POINTS FIGURE 4. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES DE Z DI 110Ω VCC D SIGNAL GENERATOR SW Y GND CL 3V DE (Note 11) tZH, tZH(SHDN) (Note 11) PARAMETER OUTPUT RE DI SW CL (pF) tHZ Y/Z X 1/0 GND 50 tLZ Y/Z X 0/1 VCC 50 tZH Y/Z 0 (Note 9) 1/0 GND 100 tZL Y/Z 0 (Note 9) 0/1 VCC 100 tZH(SHDN) Y/Z 1 (Note 12) 1/0 GND 100 tZL(SHDN) Y/Z 1 (Note 12) 0/1 VCC 100 FIGURE 5A. TEST CIRCUIT 50% 50% 0V tHZ OUTPUT HIGH VOH - 0.5V 2.3V OUT (Y, Z) VOH 0V tZL, tZL(SHDN) tLZ (Note 11) VCC OUT (Y, Z) 2.3V VOL + 0.5V OUTPUT LOW VOL FIGURE 5B. MEASUREMENT POINTS FIGURE 5. DRIVER ENABLE AND DISABLE TIMES 8 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Test Circuits and Waveforms (Continued) DE VCC 3V + Z DI CD 54Ω D DI VOD Y 0V - SIGNAL GENERATOR +VOD DIFF OUT (Y - Z) 0V -VOD FIGURE 6A. TEST CIRCUIT FIGURE 6B. MEASUREMENT POINTS FIGURE 6. DRIVER DATA RATE RE R A SIGNAL GENERATOR B 15pF B VCM + 750mV VCM RO VCM A VCM - 750mV tPLH SIGNAL GENERATOR tPHL VCC 50% RO VCM 50% 0V FIGURE 7A. TEST CIRCUIT FIGURE 7B. MEASUREMENT POINTS FIGURE 7. RECEIVER PROPAGATION DELAY AND DATA RATE RE B A 1kΩ RO R SIGNAL GENERATOR 15pF PARAMETER DE A SW RE (Note 11) 3V 50% 50% 0V SW tHZ 0 +1.5V GND tLZ 0 -1.5V VCC tZH (Note 10) 0 +1.5V GND tZL (Note 10) 0 -1.5V VCC tZH(SHDN) (Note 13) 0 +1.5V GND tZL(SHDN) (Note 13) 0 -1.5V VCC FIGURE 8A. TEST CIRCUIT VCC GND tZH, tZH(SHDN) (Note 11) tHZ OUTPUT HIGH 1.5V RO VOH - 0.5V VOH 0V tZL, tZL(SHDN) tLZ (Note 11) VCC RO 1.5V VOL + 0.5V OUTPUT LOW VOL FIGURE 8B. MEASUREMENT POINTS FIGURE 8. RECEIVER ENABLE AND DISABLE TIMES 9 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Application Information Driver (Tx) Features RS-485 and RS-422 are differential (balanced) data transmission standards used for long haul or noisy environments. RS-422 is a subset of RS-485, so RS-485 transceivers are also RS-422 compliant. RS-422 is a point-to-multipoint (multidrop) standard, which allows only one driver and up to 10 (assuming one-unit load devices) receivers on each bus. RS-485 is a true multipoint standard, which allows up to 32 one-unit load devices (any combination of drivers and receivers) on each bus. To allow for multipoint operation, the RS-485 specification requires that drivers must handle bus contention without sustaining any damage. The RS-485/RS-422 driver is a differential output device that delivers at least 1.5V across a 54Ω load (RS-485) and at least 2.4V across a 100Ω load (RS-422). The drivers feature low propagation delay skew to maximize bit width and to minimize EMI, and all drivers are three-statable via the active high DE input. Another important advantage of RS-485 is the extended common mode range (CMR), which specifies that the driver outputs and receiver inputs withstand signals that range from +12V to -7V. RS-422 and RS-485 are intended for runs as long as 4000 feet, so the wide CMR is necessary to handle ground potential differences, as well as voltages induced in the cable by external fields. The ISL3248xE is a family of ruggedized RS-485 transceivers that improves on the RS-485 basic requirements and therefore increases system reliability. The CMR increases to ±25V, while the RS-485 bus pins (receiver inputs and driver outputs) include fault protection against voltages and transients up to ±60V. Additionally, larger-than-required differential output voltages (VOD) increase noise immunity, while the ±16.5kV built-in ESD protection complements the fault protection. Receiver (Rx) Features These devices utilize a differential input receiver for maximum noise immunity and common mode rejection. Input sensitivity is better than ±200mV, as required by the RS-422 and RS-485 specifications. Receiver input (load) current surpasses the RS-422 specification of 3mA and is four times lower than the RS-485 “Unit Load (UL)” requirement of 1mA maximum. Thus, these products are known as “one-quarter UL” transceivers, and there can be up to 128 of these devices on a network while still complying with the RS-485 loading specification. The Rx functions with common mode voltages as great as ±25V, making them ideal for industrial or long networks where induced voltages are a realistic concern. All the receivers include a “full fail-safe” function that guarantees a high-level receiver output if the receiver inputs are unconnected (floating), shorted together, or connected to a terminated bus with all the transmitters disabled (i.e., an idle bus). Rx outputs feature high drive levels (typically 22mA @ VOL = 1V) to ease the design of optically coupled isolated interfaces. Except for the ISL32485E, Rx outputs are three-statable via the active low RE input. The Rx includes noise filtering circuitry to reject high-frequency signals, and typically rejects pulses narrower than 50ns (equivalent to 20Mbps). 10 The driver outputs are slew rate limited to minimize EMI and to minimize reflections in unterminated or improperly terminated networks. High Overvoltage (Fault) Protection Increases Ruggedness The ±60V (referenced to the IC GND) fault protection on the RS-485 pins makes these transceivers some of the most rugged on the market. This level of protection makes the ISL3248xE perfect for applications where power (e.g., 24V and 48V supplies) must be routed in the conduit with the data lines, or for outdoor applications where large transients are likely to occur. When power is routed with the data lines, even a momentary short between the supply and data lines will destroy an unprotected device. The ±60V fault levels of this family are at least five times higher than the levels specified for standard RS-485 ICs. The ISL3248xE protection is active whether the Tx is enabled or disabled, and even if the IC is powered down. If transients or voltages (including overshoots and ringing) greater then ±60V are possible, then additional external protection is required. Widest Common Mode Voltage (CMV) Tolerance Improves Operating Range RS-485 networks operating in industrial complexes or over long distances are susceptible to large CMV variations. Either of these operating environments may suffer from large node-to-node ground potential differences or CMV pickup from external electromagnetic sources, and devices with only the minimum required +12V to -7V CMR may malfunction. The ISL3248xE’s extended ±25V CMR is the widest available, allowing operation in environments that would overwhelm lesser transceivers. Additionally, the Rx will not phase invert (erroneously change state), even with CMVs of ±40V or differential voltages as large as 40V. Cable Invert (Polarity Reversal) Function With large node count RS-485 networks, it is common for some cable data lines to be wired backwards during installation. When this happens, the node is unable to communicate over the network. Once a technician finds the miswired node, he must then rewire the connector, which is time consuming. The ISL32483E and ISL32485E simplify this task by including cable invert pins (INV, DINV, RINV) that allow the technician to invert the polarity of the Rx input and/or the Tx output pins simply by moving a jumper to change the state of the invert pins. When the invert pin is low, the IC operates like any standard RS-485 transceiver, and the bus pins have their normal polarity definition of A and Y being noninverting and B and Z being inverting. With the invert pin high, the corresponding bus pins reverse their polarity, so B and Z are now noninverting, and A and Y become inverting. FN7785.0 January 18, 2011 ISL32483E, ISL32485E High VOD Improves Noise Immunity and Flexibility The ISL3248xE driver design delivers larger differential output voltages (VOD) than the RS-485 standard requires or than most RS-485 transmitters can deliver. The typical ±2.5V VOD provides more noise immunity than networks built using many other transceivers. Another advantage of the large VOD is the ability to drive more than two bus terminations, which allows for utilizing the ISL3248xE in “star” and other multi-terminated, nonstandard network topologies. Figure 10 details the transmitter’s VOD versus IOUT characteristic, and includes load lines for four (30Ω) and six (20Ω) 120Ω terminations. The figure shows that the driver typically delivers ±1.3V into six terminations, and the “Electrical Specifications” on page 5 guarantee a VOD of ±0.8V at 21Ω over the full temperature range. The RS-485 standard requires a minimum 1.5V VOD into two terminations, but the ISL3248xE delivers RS-485 voltage levels with 2x to 3x the number of terminations. Hot Plug Function When a piece of equipment powers up, there is a period of time in which the processor or ASIC driving the RS-485 control lines (DE, RE) is unable to ensure that the RS-485 Tx and Rx outputs are kept disabled. If the equipment is connected to a bus, a driver activating prematurely during power-up may crash the bus. To avoid this scenario, the ISL3248xE devices incorporate a “Hot Plug” function. Circuitry monitoring VCC ensures that, during power-up and power-down, the Tx and Rx outputs remain disabled, regardless of the state of DE and RE, if VCC is less than ≈3.5V. This gives the processor or ASIC a chance to stabilize and drive the RS-485 control lines to the proper states. Figure 9 illustrates the power-up and power-down performance of the ISL3248xE compared to an RS-485 IC without the Hot Plug feature. 11 2.8V 5.0 2.5 VCC VCC (V) RE = GND 3.5V 0 5.0 RL = 1kΩ 2.5 0 A/Y ISL3248XE ISL83088E RL = 1kΩ RO ISL3248XE 5.0 2.5 0 RECEIVER OUTPUT (V) The full duplex ISL32483E includes two invert pins that allow for separate control of the Rx and Tx polarities. If only the Rx cable is miswired, then only the RINV pin need be driven to a logic 1. If the Tx cable is miswired, then DINV must be connected to a logic high. The half-duplex version has only one logic pin (INV) that, when high, switches the polarity of both the Tx and the Rx blocks. DE, DI = VCC DRIVER Y OUTPUT (V) Intersil’s unique cable invert function is superior to that found on competing devices, because the Rx full fail-safe function is maintained, even when the Rx polarity is reversed. Competitor devices implement the Rx invert function simply by inverting the Rx output. This means that with the Rx inputs floating or shorted together, the Rx appropriately delivers a logic 1 in normal polarity, but outputs a logic low when the IC is operated in the inverted mode. Intersil’s innovative Rx design guarantees that, with the Rx inputs floating or shorted together (VID=0V), the Rx output remains high, regardless of the state of the invert pins. TIME (40µs/DIV) FIGURE 9. HOT PLUG PERFORMANCE (ISL3248XE) vs ISL83088E WITHOUT HOT PLUG CIRCUITRY ESD Protection All pins on the ISL3248xE devices include Class 3 (>8kV) Human Body Model (HBM) ESD protection structures that are good enough to survive ESD events commonly seen during manufacturing. Even so, the RS-485 pins (driver outputs and receiver inputs) incorporate more advanced structures that allow them to survive ESD events in excess of ±16.5kV HBM (±15kV for full-duplex version). The RS-485 pins are particularly vulnerable to ESD strikes, because they typically connect to an exposed port on the exterior of the finished product. Simply touching the port pins or connecting a cable can cause an ESD event that might destroy unprotected ICs. The new ESD structures protect the device whether or not it is powered up, and without interfering with the exceptional ±25V CMR. This built-in ESD protection minimizes the need for board-level protection structures (e.g., transient suppression diodes) and the associated, undesirable capacitive load they present. Data Rate, Cables, and Terminations RS-485/RS-422 are intended for network lengths up to 4000 feet, but the maximum system data rate decreases as the transmission length increases. These 1Mbps versions can operate at full data rates with lengths up to 800 feet (244m). Jitter is the limiting parameter at this data rate, so employing encoded data streams (e.g., Manchester coded or Return-to-Zero) may allow increased transmission distances. Twisted pair is the cable of choice for RS-485/RS-422 networks. Twisted pair cables tend to pick up noise and other electromagnetically induced voltages as common mode signals, which are effectively rejected by the differential receivers in these ICs. FN7785.0 January 18, 2011 ISL32483E, ISL32485E Proper termination is imperative to minimize reflections, and terminations are recommended unless power dissipation is an overriding concern. In point-to-point, or point-to-multipoint (single driver on bus like RS-422) networks, the main cable should be terminated in its characteristic impedance (typically 120Ω) at the end farthest from the driver. In multi-receiver applications, stubs connecting receivers to the main cable should be kept as short as possible. Multipoint (multi-driver) systems require that the main cable be terminated in its characteristic impedance at both ends. Stubs connecting a transceiver to the main cable should be kept as short as possible. As stated previously, the RS-485 specification requires that drivers survive worst-case bus contentions undamaged. These transceivers meet this requirement via driver output short circuit current limits and on-chip thermal shutdown circuitry. The driver output stages incorporate a double foldback, short circuit current limiting scheme, which ensures that the output current never exceeds the RS-485 specification, even at the common mode and fault condition voltage range extremes. The first foldback current level (≈70mA) is set to ensure that the driver never folds back when driving loads with common mode voltages up to ±25V. The very low second foldback current Typical Performance Curves DIFFERENTIAL OUTPUT VOLTAGE (V) DRIVER OUTPUT CURRENT (mA) +25°C RD = 54Ω +85°C 50 40 RD = 100Ω 30 20 10 0 0 1 Note that receiver and driver enable times increase when the transceiver enables from shutdown. Refer to Notes 9, 10, 11, 12 and 13, at the end of “Electrical Specifications” on page 5, for more information. VCC = 5V, TA = +25°C; Unless Otherwise Specified. RD = 30Ω 70 60 These BiCMOS transceivers all use a fraction of the power required by competitive devices, but they also include a shutdown feature (except the ISL32485E) that reduces the already low quiescent ICC to a 10µA trickle. These devices enter shutdown whenever the receiver and driver are simultaneously disabled (RE = VCC and DE = GND) for a period of at least 600ns. Disabling both the driver and the receiver for less than 60ns guarantees that the transceiver will not enter shutdown. 3.6 RD = 20Ω 80 In the event of a major short circuit condition, devices also include a thermal shutdown feature that disables the drivers whenever the die temperature becomes excessive. This eliminates the power dissipation, allowing the die to cool. The drivers automatically re-enable after the die temperature drops about 15°C. If the contention persists, the thermal shutdown/re-enable cycle repeats until the fault is cleared. Receivers stay operational during thermal shutdown. Low Power Shutdown Mode Built-In Driver Overload Protection 90 setting (≈9mA) minimizes power dissipation if the Tx is enabled when a fault occurs. 2 3 4 5 DIFFERENTIAL OUTPUT VOLTAGE (V) FIGURE 10. DRIVER OUTPUT CURRENT vs DIFFERENTIAL OUTPUT VOLTAGE 12 3.4 RD = 100Ω 3.2 3.0 2.8 2.6 RD = 54Ω 2.4 2.2 -40 -25 0 25 50 TEMPERATURE (°C) 75 85 FIGURE 11. DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs TEMPERATURE FN7785.0 January 18, 2011 ISL32483E, ISL32485E Typical Performance Curves VCC = 5V, TA = +25°C; Unless Otherwise Specified. (Continued) 70 2.40 RECEIVER OUTPUT CURRENT (mA) 2.45 DE = VCC, RE = X 2.35 ICC (mA) 2.30 2.25 DE = GND, RE = GND 2.20 2.15 2.10 2.05 2.00 -40 -25 0 25 50 TEMPERATURE (°C) 75 150 VOL, +85°C 40 30 20 10 0 -10 VOH, +85°C -20 VOH, +25°C 0 1 2 3 4 RECEIVER OUTPUT VOLTAGE (V) 5 FIGURE 13. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE 800 +85°C 600 100 Y OR Z = LOW BUS PIN CURRENT (µA) OUTPUT CURRENT (mA) VOL, +25°C 50 -30 85 FIGURE 12. SUPPLY CURRENT vs TEMPERATURE 60 50 +25°C 0 -50 Y OR Z = HIGH +25°C -100 400 200 0 Y or Z -200 -400 A/Y or B/Z +85°C -150 -60 -50 -40 -30 -20 -10 -600 0 10 20 30 40 50 60 -70 -50 -30 -10 0 10 30 50 70 BUS PIN VOLTAGE (V) OUTPUT VOLTAGE (V) FIGURE 14. DRIVER OUTPUT CURRENT vs SHORT CIRCUIT VOLTAGE FIGURE 15. BUS PIN CURRENT vs BUS PIN VOLTAGE 4.0 85 RD = 54Ω, CD = 50pF RD = 54Ω, CD = 50pF 3.5 75 SKEW (ns) PROPAGATION DELAY (ns) 80 70 tPLH 65 3.0 tPHL 60 2.5 55 50 -40 -25 0 25 50 75 TEMPERATURE (°C) FIGURE 16. DRIVER DIFFERENTIAL PROPAGATION DELAY vs TEMPERATURE 13 85 2.0 -40 |tPLH - tPHL| -25 0 25 50 TEMPERATURE (°C) 75 85 FIGURE 17. DRIVER DIFFERENTIAL SKEW vs TEMPERATURE FN7785.0 January 18, 2011 ISL32483E, ISL32485E 10 5 0 5 0 -5 -10 -15 -20 -25 VID = ±1V RO RO A B TIME (400ns/DIV) FIGURE 18. RECEIVER PERFORMANCE WITH ±25V CMV RD = 54Ω, CD = 50pF DI 5 0 5 RO 0 DRIVER INPUT (V) A B RECEIVER OUTPUT (V) VOLTAGE (V) 25 20 15 VCC = 5V, TA = +25°C; Unless Otherwise Specified. (Continued) DRIVER OUTPUT (V) Typical Performance Curves 3 2 1 0 -1 -2 -3 A/Y - B/Z TIME (400ns/DIV) FIGURE 19. DRIVER AND RECEIVER WAVEFORMS Die Characteristics SUBSTRATE POTENTIAL (Powered Up): GND PROCESS: Si Gate BiCMOS 14 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Revision History The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you have the latest Rev. DATE REVISION CHANGE January 18, 2011 FN7785.0 Initial Release Products Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks. Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a complete list of Intersil product families. *For a complete listing of Applications, Related Documentation and Related Parts, please see the respective device information page on intersil.com: ISL32483E, ISL32485E To report errors or suggestions for this data sheet, please go to www.intersil.com/ask our staff FITs are available from our web site at http://rel.intersil.com/reports/search.php For additional products, see www.intersil.com/product_tree Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems as noted in the quality certifications found at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 15 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Package Outline Drawing M14.15 14 LEAD NARROW BODY SMALL OUTLINE PLASTIC PACKAGE Rev 1, 10/09 8.65 A 3 4 0.10 C A-B 2X 6 14 DETAIL"A" 8 0.22±0.03 D 6.0 3.9 4 0.10 C D 2X 0.20 C 2X 7 PIN NO.1 ID MARK 5 0.31-0.51 B 3 (0.35) x 45° 4° ± 4° 6 0.25 M C A-B D TOP VIEW 0.10 C 1.75 MAX H 1.25 MIN 0.25 GAUGE PLANE C SEATING PLANE 0.10 C 0.10-0.25 1.27 SIDE VIEW (1.27) DETAIL "A" (0.6) NOTES: 1. Dimensions are in millimeters. Dimensions in ( ) for Reference Only. 2. Dimensioning and tolerancing conform to AMSEY14.5m-1994. 3. Datums A and B to be determined at Datum H. (5.40) 4. Dimension does not include interlead flash or protrusions. Interlead flash or protrusions shall not exceed 0.25mm per side. 5. The pin #1 indentifier may be either a mold or mark feature. (1.50) 6. Does not include dambar protrusion. Allowable dambar protrusion shall be 0.10mm total in excess of lead width at maximum condition. 7. Reference to JEDEC MS-012-AB. TYPICAL RECOMMENDED LAND PATTERN 16 FN7785.0 January 18, 2011 ISL32483E, ISL32485E Package Outline Drawing M8.15 8 LEAD NARROW BODY SMALL OUTLINE PLASTIC PACKAGE Rev 2, 11/10 DETAIL "A" 1.27 (0.050) 0.40 (0.016) INDEX 6.20 (0.244) 5.80 (0.228) AREA 0.50 (0.20) x 45° 0.25 (0.01) 4.00 (0.157) 3.80 (0.150) 1 2 8° 0° 3 0.25 (0.010) 0.19 (0.008) SIDE VIEW “B” TOP VIEW 2.41 (0.095) SEATING PLANE 5.00 (0.197) 4.80 (0.189) 1.75 (0.069) 1.35 (0.053) 1 8 2 7 0.76 (0.030) 1.27 (0.050) 3 6 4 5 -C- 1.27 (0.050) 0.51(0.020) 0.33(0.013) SIDE VIEW “A 0.25(0.010) 0.10(0.004) 0.200 TYPICAL RECOMMENDED LAND PATTERN NOTES: 1. Dimensioning and tolerancing per ANSI Y14.5M-1982. 2. Package length does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. 3. Package width does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per side. 4. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 5. Terminal numbers are shown for reference only. 6. The lead width as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value of 0.61mm (0.024 inch). 7. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact. 8. This outline conforms to JEDEC publication MS-012-AA ISSUE C. 17 FN7785.0 January 18, 2011