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| ST485A Very high speed low power RS-485/RS-422 transceiver General features s s s s s Low supply current: 5mA max High data rate > 30Mbps Designed for RS 485 interface applications -7 to 12 common mode input voltage range Driver maintains high impedance in 3-state or with the power off 70mV typical input hysteresis Operate from single 5 supply 4kV ESD protection Current limiting and thermal shutdown for driver overload protection Latch-up free up to 500mA Driver is short-circuit current limited and is protected against excessive power dissipation by thermal shutdown circuitry that place the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic high output if both inputs are open circuit. The ST485A is designed for bi-directional data communications or multipoint bus transmission lines. DIP-8 SO-8 s s s s s Description The ST485A is a low power, high speed transceiver for RS-485 and RS-422 communications. The device contains one driver and one receiver in half duplex configuration. The ST485A draws 3mA (typ.) of supply current when unloaded or fully loaded with disabled drivers. It operates from a single 5V supply. Order code Part number ST485ACN ST485ABN ST485ACDR ST485ABDR March 2006 Temperature range 0 to 70 C -40 to 85 C 0 to 70 C -40 to 85 C Package DIP-8 DIP-8 SO-8 (Tape & reel) SO-8 (Tape & reel) Rev 2 Comments 50parts per tube / 40tube per box 50parts per tube / 40tube per box 2500 parts per reel 2500 parts per ree 1/19 www.st.com 19 Contents ST485A Contents 1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 3 4 Truth tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1 4.2 4.3 4.4 4.5 Logic input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Driver switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Receiver switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 6 7 Test circuit and typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2/19 ST485A Pin configuration 1 Pin configuration Figure 1. Pin configuration 1.1 Pin description Table 1. Pin n 1 Pin description Name and function Receiver output. If A>B by 200mV, RO will be high; if ASymbol RO 2 RE 3 DE 4 5 6 7 8 DI GND A B VCC 3/19 Truth tables ST485A 2 Truth tables Table 2. Truth table (driver) Inputs Outputs DI H L X B L H Z A H L Z Mode A Normal Normal Normal RE X X L DE H H L Note: Table 3. X = Don't care; Z = High impedance Truth table (receiver) Inputs RE L L L DE L L L Outputs Mode A-B -0.2V -0.2V RO H L H Normal Normal Normal INPUTS OPEN Note: X = Don't care; Z = High impedance 4/19 ST485A Maximum ratings 3 Table 4. Symbol VCC VI VDI VDO VRI VRO Maximum ratings Absolute maximum ratings Parameter Supply voltage Control input voltage (RE, DE) Driver input voltage (DI) Driver output voltage (A, B) Receiver input voltage (A, B) Receiver output voltage (RO) Value 7 -0.3 to 7 -0.3 to 7 -7.5 to 12.5 -7.5 to 12.5 -0.3 to (VCC + 0.3) Unit V V V V V V Note: Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. 5/19 Electrical characteristics ST485A 4 Electrical characteristics (V CC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (Note: 1) DC Electrical characteristics Parameter Test conditions No load, VRE=0V or V CC VDE = VCC VDE = 0V Min Typ 2.3 2.6 10 10 Max 5 5 Unit mA mA pF pF Table 5. Symbol ISUPPLY VCC Power supply current CI/O CAB Input/output capacitance Driver output capacity 4.1 Table 6. Symbol VIL VIH IIN1 IIN2 Logic input (V CC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (Note: 1) Logic input electrical characteristics Parameter Input logic threshold low Input logic threshold high Logic input current Input current (A, B) DE, DI, RE DE, DI, RE DE, DI, RE VDE=0V, VCC = 0 or 5.25V VIN=12V VIN=-7V 2 2.0 1 -0.8 Test conditions Min Typ Max 0.8 Unit V V A mA mA 4.2 Table 7. Symbol VOD1 VOD2 VOD Transmitter (V CC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (Note: 1) Transmitter electrical characteristics Parameter Differential driver output (No load) Differential driver output (with load) Change in magnitude of driver differential output voltage for complementary output states (Note: 1) Driver common mode output voltage Change in magnitude of driver common mode output voltage (Note: 1) Driver short circuit output current RL= 54 (RS-422) VCM= -7V to 12V 1.5 2.7 Test conditions Min Typ Max 5 5 Unit V V RL= 27 or 50 0 0.2 V VOC VOC IOSD RL= 27 or 50 1 3 V RL= 54 or 100 VO= -7V to 12V 0 0.2 250 V mA 6/19 ST485A Electrical characteristics 4.3 Table 8. Symbol VTH VTH VOH VOL IOZR RRIN IOSR Receiver (V CC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (Note: 1) Receiver electrical characteristics Parameter Receiver Differential Threshold Voltage Receiver Input Hysteresis Receiver Output High Voltage Receiver Output Low Voltage 3-State (High Impedance) Output Current at Receiver Receiver Input Resistance Receiver Short-Circuit Current Test conditions VCM = -7V to 12V VCM = 0V IOUT = -4mA, VID = 200mV IOUT = 4mA, V ID = -200mV VO = 0.4V to 2.4V VCM = -7V to 12V VO = 0V to VCC 12 7 24 95 3.5 Min -0.2 70 4.7 0.2 0.4 1 Typ Max 0.2 Unit V mV V V A K mA 4.4 Table 9. Symbol DR tPLH tPHL tSKEW tTLH tTHL tPZL tPZH tPHZ tPLZ tSK(EN) tSK(DS) Driver switching (V CC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (See Note: 1, 3) Driver switching characteristics Parameter Maximum data rate Propagation delay input to output Differential output delay skew Rise or fall differential time Output enable time Output enable time Output disable time Output disable time Synchronous driver operation a-b at enable Synchronous driver operation A-B at disable 4 Test conditions Jitter < 5% RL= 54, CL1=C L2=50pF, (Figure 1) RL= 54, CL1=C L2=50pF, (Figure 1) RL= 54, CL1=C L2=50pF, (Figure 1) CL= 50pF, S1 Closed CL= 50pF, S2 Closed CL= 15pF, S2 Closed CL= 15pF, S1 Closed Min 30 Typ 50 18 0.5 8 30 2 12 30 30 30 30 2 6 Max Unit Mbps ns ns ns ns ns ns ns ns ns 7/19 Electrical characteristics ST485A 4.5 Table 10. Symbol tPLH tPHL tRPDS tPZL tPZH tPHZ tPLZ Receiver switching (V CC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (See Note: 1, 3) Driver switching characteristics Parameter Propagation Delay Test conditions CL = 15pF Min Typ 18 0.5 7 7 7 7 Max 30 2 12 12 12 12 Unit ns ns ns ns ns ns |tPLH - tPHL| Propagation delay skew CL = 15pF Output enable time Output enable time Output disable time Output disable time CRL = 15pF, S1 Closed CRL = 15pF, S2 Closed CRL = 15pF, S2 Closed CRL = 15pF, S1 Closed Note: 1 2 3 All currents into device pins are positive; all currents out of device pins are negative; all voltages are referenced to device ground unless specified. Applies to peak current. See typical Operating Characteristics. tr=tf 6ms. 8/19 ST485A Test circuit and typical characteristics 5 Test circuit and typical characteristics Figure 2. Driver DC test load Figure 3. Receiver timing test load Figure 4. Driver/receiver timing test circuit 9/19 Test circuit and typical characteristics Figure 5. Driver Timing Test Load ST485A Figure 6. Driver timing test load Figure 7. Driver enable and disable time 10/19 ST485A Figure 8. Receiver propagation delay Test circuit and typical characteristics Figure 9. Receiver enable and disable time 11/19 Test circuit and typical characteristics Figure 10. Receiver output current vs. output voltage (output low) Figure 11. ST485A Receiver output current vs. output voltage (output high) Figure 12. Driver Diff. Output Voltage vs Common Mode Voltage (Diff. Output Low) Figure 13. Driver Diff. Output Voltage vs Common Mode Voltage (Diff. Output Low) 12/19 ST485A Test circuit and typical characteristics Figure 14. Driver Short Circuit Current vs Line Figure 15. Driver Short Circuit Current vs. Voltage (Output High) Line Voltage (Output Low) Figure 16. Receiver Input Current vs Input Voltage 13/19 Package mechanical data ST485A 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK(R) packages. These packages have a Lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com 14/19 ST485A Package mechanical data Plastic DIP-8 MECHANICAL DATA mm. DIM. MIN. A a1 B B1 b b1 D E e e3 e4 F I L Z 0.44 3.3 1.6 0.017 8.8 2.54 7.62 7.62 7.1 4.8 0.130 0.063 0.38 0.7 1.39 0.91 0.5 0.5 9.8 0.346 0.100 0.300 0.300 0.280 0.189 0.015 1.65 1.04 TYP 3.3 0.028 0.055 0.036 0.020 0.020 0.386 0.065 0.041 MAX. MIN. TYP. 0.130 MAX. inch P001F 15/19 Package mechanical data ST485A SO-8 MECHANICAL DATA DIM. A A1 A2 B C D E e H h L k ddd 0.1 5.80 0.25 0.40 mm. MIN. 1.35 0.10 1.10 0.33 0.19 4.80 3.80 1.27 6.20 0.50 1.27 0.228 0.010 0.016 TYP MAX. 1.75 0.25 1.65 0.51 0.25 5.00 4.00 MIN. 0.053 0.04 0.043 0.013 0.007 0.189 0.150 0.050 0.244 0.020 0.050 inch TYP. MAX. 0.069 0.010 0.065 0.020 0.010 0.197 0.157 8 (max.) 0.04 0016023/C 16/19 ST485A Package mechanical data Tape & Reel SO-8 MECHANICAL DATA mm. DIM. MIN. A C D N T Ao Bo Ko Po P 8.1 5.5 2.1 3.9 7.9 12.8 20.2 60 22.4 8.5 5.9 2.3 4.1 8.1 0.319 0.216 0.082 0.153 0.311 TYP MAX. 330 13.2 0.504 0.795 2.362 0.882 0.335 0.232 0.090 0.161 0.319 MIN. TYP. MAX. 12.992 0.519 inch 17/19 Revision history ST485A 7 Table 11. Date Revision history Revision history Revision 2 Changes Order codes has been updated and new template. 28-Mar-2006 18/19 ST485A Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST's terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein. UNLESS OTHERWISE SET FORTH IN ST'S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZE REPRESENTATIVE OF ST, ST PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS, WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. (c) 2006 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 19/19 |
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