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| ST485A VERY HIGH SPEED LOW POWER RS-485/RS-422 TRANSCEIVER s s s s s 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 MANTAINS 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 DIP SOP 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 ORDERING CODES Type ST485ACN ST485ABN ST485ACD ST485ABD ST485ACDR ST485ABDR Temperature Range 0 to 70 C -40 to 85 C 0 to 70 C -40 to 85 C 0 to 70 C -40 to 85 C Package unloaded or fully loaded with disabled drivers. It operates from a single 5V supply. 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. Comments 50parts per tube / 40tube per box 50parts per tube / 40tube per box 100parts per tube / 20tube per box 100parts per tube / 20tube per box 2500 parts per reel 2500 parts per reel DIP-8 DIP-8 SO-8 (Tube) SO-8 (Tube) SO-8 (Tape & Reel) SO-8 (Tape & Reel) November 2002 1/13 ST485A PIN CONFIGURATION PIN DESCRIPTION PlN N 1 2 SYMBOL RO RE NAME AND FUNCTION Receiver Output. If A>B by 200mV, RO will be high; if A3 DE 4 5 6 7 8 DI GND A B VCC TRUTH TABLE (DRIVER) INPUTS RE X X L DE H H L DI H L X OUTPUTS MODE B L H Z A H L Z Normal Normal Normal TRUTH TABLE (RECEIVER) INPUTS RE DE L L L L L L A-B -0.2V -0.2V Inputs Open OUTPUT MODE RO H L H Normal Normal Normal X= Don't Care; Z=High Impedance X= Don't Care; Z=High Impedance 2/13 ST485A ABSOLUTE MAXIMUM RATINGS Symbol VCC VI VDI VDO VRI VRO 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) Parameter 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 Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (See Note 1) Symbol Parameter Test Conditions No Load, VRE=0V or VCC VDE=VCC VDE=0V CI/O CAB Input/Output Capacitance Driver Output Capacity Min. Typ. 2.3 2.6 10 10 Max. 5 5 Unit mA mA pF pF ISUPPLY VCC Power Supply Current LOGIC INPUT ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to TA = 25C, VCC = 5V) (See Note 1 Symbol VIL VIH IIN1 IIN2 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 3/13 ST485A TRANSMITTER ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to Ta = 25C, VCC = 5V) (See Note 1) Symbol VOD1 VOD2 VOD Parameter Differential Driver Output (No load) Differential Driver Output (With Load) Change in magnitude of Driver Differential Output Voltage for Complementary Output States (Note1) Driver Common Mode Output Voltage Change in magnitude of Driver Common Mode Output Voltage (Note1) Driver Short Circuit Output Current Test Conditions Min. Typ. Max. 5 RL= 54 (RS-422) VCM=-7V to 12V RL= 27 or 50 1.5 2.7 0 5 0.2 Unit V V V VOC VOC RL= 27 or 50 RL= 54 or 100 1 0 3 0.2 V V IOSD VO=-7V to 12V 250 mA RECEIVER ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to Ta = 25C, VCC = 5V) (See Note 1) Symbol VTH VTH VOH VOL IOZR RRIN IOSR 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, VID = -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 4/13 ST485A DRIVER SWITCHING CHARACTERISTICS VCC = 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) Symbol DR tPLH tPHL tSKEW tTLH tTHL tPZL tPZH tPHZ tPLZ tSK(EN) tSK(DS) 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 Jitter <5% RL= 54 RL= 54 RL= 54 CL= 50pF CL= 50pF CL= 15pF CL= 15pF CL1=CL2=50pF, (Figure 1) CL1=CL2=50pF, (Figure 1) CL1=CL2=50pF, (Figure 1) S1 Closed S2 Closed S2 Closed S1 Closed Test Conditions Min. 30 Typ. 50 18 0.5 8 30 2 12 30 30 30 30 2 4 6 Max. Unit Mbps ns ns ns ns ns ns ns ns ns RECEIVER SWITCHING CHARACTERISTICS VCC = 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) Symbol tPLH tPHL tRPDS tPZL tPZH tPHZ tPLZ Parameter Propagation Delay |tPLH - tPHL| Propagation Delay Skew Output Enable Time Output Enable Time Output Disable Time Output Disable Time CL = 15pF CL = 15pF CRL = 15pF S1 Closed CRL = 15pF S2 Closed CRL = 15pF S2 Closed CRL = 15pF S1 Closed Test Conditions Min. Typ. 18 0.5 7 7 7 7 Max. 30 2 12 12 12 12 Unit ns ns ns ns ns ns Note 1: All currents into device pins are positive; all cuttents out of device pins are negative; all voltages are referenced to device ground unless specified. Note 2: Applies to peak current. See typical Operating Characteristics. Note 3: tr=tf 6ms 5/13 ST485A TEST CIRCUITS AND TYPICAL CHARACTERISTICS Figure 1 : Driver DC Test Load Figure 2 : Receiver Timing Test Load Figure 3 : Drive/Receiver Timing Test Circuit 6/13 ST485A Figure 4 : Driver Timing Test Load Figure 5 : Driver Propagation Delay 7/13 ST485A Figure 6 : Driver Enable and Disable Time Figure 7 : Receiver Propagation Delay 8/13 ST485A Figure 8 : Receiver Enable and Disable Time Figure 9 : Receiver Output Current vs Output Voltage (Output Low) Figure 10 : Receiver Output Current vs Output Voltage (Output High) 9/13 ST485A Figure 11 : Driver Diff. Output Voltage vs Common Mode Voltage (Diff. Output Low) Figure 14 : Driver Short Circuit Current vs. Line Voltage (Output Low) Figure 12 : Driver Diff. Output Voltage vs Common Mode Voltage (Diff. Output Low) Figure 15 : Receiver Input Current vs Input Voltage Figure 13 : Driver Short Circuit Current vs Line Voltage (Output High) 10/13 ST485A 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 11/13 ST485A SO-8 MECHANICAL DATA DIM. A a1 a2 a3 b b1 C c1 D E e e3 F L M S 3.8 0.4 4.8 5.8 1.27 3.81 4.0 1.27 0.6 8 (max.) 0.149 0.015 5.0 6.2 0.65 0.35 0.19 0.25 0.1 mm. MIN. TYP MAX. 1.75 0.25 1.65 0.85 0.48 0.25 0.5 45 (typ.) 0.189 0.228 0.050 0.150 0.157 0.050 0.023 0.196 0.244 0.025 0.013 0.007 0.010 0.003 MIN. inch TYP. MAX. 0.068 0.009 0.064 0.033 0.018 0.010 0.019 0016023 12/13 ST485A Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement 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 STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. (c) The ST logo is a registered trademark of STMicroelectronics (c) 2002 STMicroelectronics - Printed in Italy - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom - United States. (c) http://www.st.com 13/13 |
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