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| ST491A LOW POWER HIGH SPEED RS-485/RS-422 TRANSCEIVER s s s s s s s s LOW SUPPLY CURRENT: 5mA MAX DESIGNED FOR RS485 INTERFACE APPLICATIONS -7 TO 12 COMMON MODE INPUT VOLTAGE RANGE 70mV TYPICAL INPUT HYSTERESIS DESIGNED FOR 25Mbps OPERATION OPERATE FROM SINGLE 5 SUPPLY 4kV ESD PROTECTION CURRENT LIMITING AND THERMAL SHUTDOWN FOR DRIVER OVERLOAD PROTECTION DIP SOP DESCRIPTION The ST491A is a low power transceiver for RS-485 and RS-422 communications. The device contains one driver and one receiver in full duplex configuration. The ST491A draws 5mA (typ.) of supply current when unloaded and operates from a single 5V supply. ORDERING CODES Type ST491ACN ST491ABN ST491ACD ST491ABD ST491ACDR ST491ABDR 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 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. Comments 25parts per tube / 40tube per 25parts per tube / 40tube per 50parts per tube / 20tube per 50parts per tube / 20tube per 2500 parts per reel 2500 parts per reel box box box box DIP-14 DIP-14 SO-14 (Tube) SO-14 (Tube) SO-14 (Tape & Reel) SO-14 (Tape & Reel) July 2003 1/12 ST491A PIN CONFIGURATION PIN DESCRIPTION PlN N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SYMBOL NC RO RE DE DI GND GND NC Y Z B A NC VCC NAME AND FUNCTION Not Connected Receiver Output. Receiver Output Enable Driver Output Enable Inverting Driver Input. Ground Ground Not Connected Non-inverting Driver Output Inverting Driver Output Inverting Receiver Input Non-inverting Receiver Input Not Connected Supply Voltage TRUTH TABLE (DRIVER) INPUT DI L H X DE H H L Y L H Z OUTPUTS Z H L Z TRUTH TABLE (RECEIVER) INPUT A-B -0.2V between -0.2V to 0.2V -0.2V OPEN X RE L L L L H OUTPUT RO H ? L H Z X= Don't Care; Z=High Impedance ?= Irrelevant; X= Don't Care; Z=High Impedance 2/12 ST491A ABSOLUTE MAXIMUM RATINGS Symbol VCC VDI VY, VZ VA, VB VRO ESD Supply Voltage Driver Input Voltage Driver Output Voltage Receiver Input Voltage Receiver Output Voltage Human Body Model Parameter Value 7 -0.5 to 7 -7.5 to 12.5 -7.5 to 12.5 -0.3 to (VCC + 0.3) 3.5 Unit V V V V V KV 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) Symbol CIN CYZ COUT Parameter Input Capacitance Driver Output Capacitance Output Capacitance Test Conditions Min. Typ. 2 1.8 1.2 2.3 Max. 5 Unit mA pF pF pF ISUPPLY No Load Supply Current TRANSMITTER ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to Ta = 25C) Symbol VOD1 VOD2 VOD3 VOD Parameter Differential Drive Output (No load) Differential Drive Output (With Load) Differential Drive 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) Power Off Output Current Driver Short Circuit Output Current Input Logic Threshold Low Input Logic Threshold High Test Conditions Min. Typ. Max. VCC RL= 54 (RS-422) (Figure 1) RL= 100 (RS-422) (Figure 1) RL= 54 or 100 (Figure 1) 1.5 2 2.6 3 0 0.2 5 Unit V V V V VOC VOC RL= 54 (Figure 1) RL= 54 (Figure 1) 1 0 3 0.2 V V IOFF IOSD VIL VIH VCC = 0V VO=-7V to 12V 35 100 250 0.8 2 A mA V V VO=-7V to 12V 3/12 ST491A RECEIVER ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to Ta = 25C) Symbol IIN VTH VTH VOH VOL RRIN Parameter Input Current (A, B) Receiver Differential Threshold Voltage Receiver Input Hysteresis Receiver Output High Voltage Receiver Output Low Voltage Receiver Input Resistance Test Conditions other input=0V VCC= 0 or 5.25V VCM = -7V to 12V VCM = 0V IOUT = -8mA, VID = 200mV IOUT = 8mA, VID = -200mV VCM = -7V to 12V 12 3.5 VIN=12V VIN=-7V -0.2 70 4.7 0.3 24 0.5 Min. Typ. 0.5 -0.35 Max. 1 -0.8 0.2 Unit mA mA V mV V V K DRIVER SWITCHING CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85C, unless otherwise specified. Typical values are referred to Ta = 25C) Symbol DR tPLH tPHL tSKEW tTLH tTHL tPZL tPZH tPHZ tPLZ 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 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. 25 Typ. 50 10 1 8 14 14 10 16 16 3 12 25 25 25 25 Max. Unit Mbps 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) Symbol tPLH tPHL tSKD tTLH tTHL tPZL tPZH tPHZ tPLZ Parameter Propagation Delay Input to Output CL = 15pF Test Conditions (Figures 2,4) (Figures 2,4) (Figures 2,4) Min. Typ. 19 1 6 6 7 6 6 12 12 12 12 Max. 30 3 Unit ns ns ns ns ns ns ns |tPLH - tPHL| Receiver Output CL = 15pF Skew Rise or Fall Time 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 4/12 ST491A TEST CIRCUITS AND TYPICAL CHARACTERISTICS Figure 1 : Driver DC Test Load Figure 2 : Receiver Timing Test Load Figure 3 : Driver/Receiver Timing Test Circuit 5/12 ST491A Figure 4 : Driver Timing Test Load Figure 5 : Driver Propagation Delay 6/12 ST491A Figure 6 : Receiver Propagation Delay Figure 7 : Receiver Output Current vs Output Voltage (Output Low) Figure 9 : Driver Diff. Output Voltage vs Common Mode Voltage (Diff. Output Low) Figure 8 : Receiver Output Current vs Output Voltage (Output High) Figure 10 : Driver Diff. Output Voltage vs Common Mode Voltage (Diff. Output High) 7/12 ST491A Figure 11 : Driver Short Circuit Current vs Line Voltage (Output High) Figure 13 : Receiver Input Current vs Input Voltage Figure 12 : Driver Short Circuit Current vs. Line Voltage (Output Low) 8/12 ST491A Plastic DIP-14 MECHANICAL DATA mm. DIM. MIN. a1 B b b1 D E e e3 F I L Z 1.27 3.3 2.54 0.050 8.5 2.54 15.24 7.1 5.1 0.130 0.100 0.51 1.39 0.5 0.25 20 0.335 0.100 0.600 0.280 0.201 1.65 TYP MAX. MIN. 0.020 0.055 0.020 0.010 0.787 0.065 TYP. MAX. inch P001A 9/12 ST491A SO-14 MECHANICAL DATA DIM. A a1 a2 b b1 C c1 D E e e3 F G L M S 3.8 4.6 0.5 8.55 5.8 1.27 7.62 4.0 5.3 1.27 0.68 8 (max.) 0.149 0.181 0.019 8.75 6.2 0.35 0.19 0.5 45 (typ.) 0.336 0.228 0.050 0.300 0.157 0.208 0.050 0.026 0.344 0.244 0.1 mm. MIN. TYP MAX. 1.75 0.2 1.65 0.46 0.25 0.013 0.007 0.019 0.003 MIN. inch TYP. MAX. 0.068 0.007 0.064 0.018 0.010 PO13G 10/12 ST491A Tape & Reel SO-14 MECHANICAL DATA mm. DIM. MIN. A C D N T Ao Bo Ko Po P 6.4 9 2.1 3.9 7.9 12.8 20.2 60 22.4 6.6 9.2 2.3 4.1 8.1 0.252 0.354 0.082 0.153 0.311 TYP MAX. 330 13.2 0.504 0.795 2.362 0.882 0.260 0.362 0.090 0.161 0.319 MIN. TYP. MAX. 12.992 0.519 inch 11/12 ST491A 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) 2003 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 12/12 |
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