ST491A LOW POWER HIGH SPEED RS-485/RS-422 TRANSCEIVER ■ ■ ■ ■ ■ ■ ■ ■ 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 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. DIP SOP 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. ORDERING CODES Type Temperature Range Package ST491ACN ST491ABN ST491ACD ST491ABD ST491ACDR ST491ABDR 0 to 70 °C -40 to 85 °C 0 to 70 °C -40 to 85 °C 0 to 70 °C -40 to 85 °C DIP-14 DIP-14 SO-14 (Tube) SO-14 (Tube) SO-14 (Tape & Reel) SO-14 (Tape & Reel) July 2003 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 1/12 ST491A PIN CONFIGURATION PIN DESCRIPTION PlN N° SYMBOL 1 2 3 4 5 6 7 8 9 10 11 12 13 NC RO RE DE DI GND GND NC Y Z B A NC VCC 14 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 (RECEIVER) TRUTH TABLE (DRIVER) INPUT OUTPUTS INPUT OUTPUT DI DE Y Z A-B RE RO L H X H H L L H Z H L Z ≥ -0.2V between -0.2V to 0.2V ≤ -0.2V OPEN X L L L L H 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 Parameter VCC Supply Voltage VDI Driver Input Voltage Value Unit 7 V -0.5 to 7 V VY, VZ Driver Output Voltage -7.5 to 12.5 V VA, VB Receiver Input Voltage -7.5 to 12.5 V VRO Receiver Output Voltage ESD Human Body Model -0.3 to (VCC + 0.3) V 3.5 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 85°C, unless otherwise specified. Typical values are referred to TA = 25°C) Symbol Parameter Test Conditions Min. ISUPPLY No Load Supply Current Typ. Max. Unit 2 5 mA CIN Input Capacitance 1.8 pF CYZ Driver Output Capacitance 1.2 pF Output Capacitance 2.3 pF COUT TRANSMITTER ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C) Symbol Parameter VOD1 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 VOD2 VOD3 ∆VOD VOC ∆VOC IOFF VIL Driver Short Circuit Output Current Input Logic Threshold Low VIH Input Logic Threshold High IOSD Test Conditions Min. Typ. RL= 54Ω (RS-422) (Figure 1) 1.5 2.6 RL= 100Ω (RS-422) (Figure 1) 2 3 RL= 54Ω or 100Ω (Figure 1) RL= 54Ω (Figure 1) 0 1 RL= 54Ω (Figure 1) VCC = 0V 0 VO=-7V to 12V VO=-7V to 12V ± 35 Max. Unit VCC V 5 V V 0.2 V 3 V 0.2 V ± 100 µA ± 250 mA 0.8 2 V V 3/12 ST491A RECEIVER ELECTRICAL CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C) Symbol IIN VTH ∆VTH VOH VOL RRIN Parameter Input Current (A, B) Test Conditions other input=0V VCC= 0 or 5.25V Receiver Differential Threshold Voltage Receiver Input Hysteresis VCM = -7V to 12V Receiver Output High Voltage Receiver Output Low Voltage Receiver Input Resistance IOUT = -8mA, VID = 200mV Min. Typ. Max. Unit VIN=12V 0.5 1 mA VIN=-7V -0.35 -0.8 mA 0.2 V -0.2 VCM = 0V 3.5 IOUT = 8mA, VID = -200mV VCM = -7V to 12V 70 mV 4.7 V 0.3 12 0.5 24 V KΩ DRIVER SWITCHING CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C) Symbol Parameter Test Conditions Min. Typ. 25 50 Max. Unit DR Maximum Data Rate Jitter <5% tPLH tPHL Propagation Delay Input to Output RL= 54Ω CL1=CL2=50pF, (Figure 1) 10 16 ns RL= 54Ω CL1=CL2=50pF, (Figure 1) 1 3 ns tTLH tTHL Differential Output Delay Skew Rise or Fall Differential Time RL= 54Ω CL1=CL2=50pF, (Figure 1) 8 12 ns tPZL Output Enable Time CL= 50pF S1 Closed 14 25 ns tPZH Output Enable Time CL= 50pF S2 Closed 14 25 ns tPHZ Output Disable Time CL= 15pF S2 Closed 10 25 ns tPLZ Output Disable Time CL= 15pF S1 Closed 16 25 ns tSKEW Mbps RECEIVER SWITCHING CHARACTERISTICS VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C) Symbol Parameter Test Conditions Min. Typ. Max. Unit tPLH tPHL Propagation Delay Input to Output CL = 15pF (Figures 2,4) 19 30 ns tSKD |tPLH - tPHL| Receiver Output CL = 15pF Skew Rise or Fall Time CL = 15pF (Figures 2,4) 1 3 ns (Figures 2,4) 6 tTLH tTHL ns tPZL Output Enable Time CRL = 15pF S1 Closed 6 12 ns tPZH Output Enable Time CRL = 15pF S2 Closed 7 12 ns tPHZ Output Disable Time CRL = 15pF S2 Closed 6 12 ns tPLZ Output Disable Time CRL = 15pF S1 Closed 6 12 ns 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 12 : Driver Short Circuit Current vs. Line Voltage (Output Low) 8/12 Figure 13 : Receiver Input Current vs Input Voltage ST491A Plastic DIP-14 MECHANICAL DATA mm. inch DIM. MIN. a1 0.51 B 1.39 TYP MAX. MIN. TYP. MAX. 0.020 1.65 0.055 0.065 b 0.5 0.020 b1 0.25 0.010 D 20 0.787 E 8.5 0.335 e 2.54 0.100 e3 15.24 0.600 F 7.1 0.280 I 5.1 0.201 L Z 3.3 1.27 0.130 2.54 0.050 0.100 P001A 9/12 ST491A SO-14 MECHANICAL DATA DIM. mm. MIN. TYP A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.2 a2 MAX. 0.003 0.007 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.5 0.019 c1 45˚ (typ.) D 8.55 8.75 0.336 0.344 E 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 7.62 0.300 F 3.8 4.0 0.149 0.157 G 4.6 5.3 0.181 0.208 L 0.5 1.27 0.019 0.050 M S 0.68 0.026 8 ˚ (max.) PO13G 10/12 ST491A Tape & Reel SO-14 MECHANICAL DATA mm. inch DIM. MIN. A TYP MAX. MIN. 330 MAX. 12.992 C 12.8 D 20.2 0.795 N 60 2.362 T 13.2 TYP. 0.504 22.4 0.519 0.882 Ao 6.4 6.6 0.252 0.260 Bo 9 9.2 0.354 0.362 Ko 2.1 2.3 0.082 0.090 Po 3.9 4.1 0.153 0.161 P 7.9 8.1 0.311 0.319 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. © The ST logo is a registered trademark of STMicroelectronics © 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. © http://www.st.com 12/12