ST485 LOW POWER RS-485/RS-422 TRANSCEIVER ■ ■ ■ ■ ■ ■ ■ ■ ■ LOW QUIESCENT CURRENT: 300µA DESIGNED FOR RS-485 INTERFACE APPLICATIONS -7V TO 12V COMMON MODE INPUT VOLTAGE RANGE DRIVER MAINTAINS HIGH IMPEDANCE IN 3-STATE OR WITH THE POWER OFF 70mV TYPICAL INPUT HYSTERESIS 30ns PROPAGATION DELAYS, 5ns SKEW OPERATE FROM A SINGLE 5V SUPPLY CURRENT LIMITING AND THERMAL SHUTDOWN FOR DRIVER OVERLOAD PROTECTION ALLOWS UP TO 64 TRANSCEIVERS ON THE BUS DESCRIPTION The ST485 is al low power transceiver for RS-485 and RS-422 communication. Each part contains one driver and one receiver. This transceiver draw 300µA (typ.) of supply current when unloaded or fully loaded with disabled drivers. DIP SOP 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 placed the driver outputs into a high-impedance state. . The ST485 is designed for bi-directional data communications on multipoint bus transmission line (half-duplex applciations). ORDERING CODES Type Temperature Range Package Comments ST485CN ST485BN ST485CD ST485BD ST485CDR ST485BDR 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-8 DIP-8 SO-8 (Tube) SO-8 (Tube) SO-8 (Tape & Reel) SO-8 (Tape & Reel) 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 November 2001 1/12 ST485 PIN CONFIGURATION PIN DESCRIPTION PlN N° SYMBOL 1 2 3 4 5 6 7 RO RE DE DI GND A B V CC 8 NAME AND FUNCTION Receiver Output Receiver Output Enable Driver Output Enable Driver Input Ground Non-inverting Receiver Input and Non-inverting Driver Output Inverting Receiver Input and Inverting Driver Output Supply Voltage TRUTH TABLE (RECEIVER) TRUTH TABLE (DRIVER) INPUTS INPUTS OUTPUTS OUTPUT RE DE DI B A RE DE A-B RO X X X H H L H L X L H Z H L Z L L L H L L L L ≥ +0.2V ≤ -0.2V INPUTS OPEN X H L H Z X= Don’t Care; Z=High Impedance X= Don’t Care; Z=High Impedance ABSOLUTE MAXIMUM RATINGS Symbol V CC Parameter Supply Voltage Value Unit 12 V VI Control Input Voltage (RE, DE) -0.5 to (VCC + 0.5) V VDI Driver Input Voltage (DI) -0.5 to (VCC + 0.5) V V DO Driver Output Voltage (A, B) ± 12.5 V VRI Receiver Input Voltage (A, B) ± 12.5 V V RO Receiver Output Voltage (RO) -0.5 to (VCC + 0.5) V Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. 2/12 ST485 DC ELECTRICAL CHARACTERISTICS (VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) (See Note 1) Symbol V OD1 V OD2 ∆V OD Parameter Differential Driver Output (No Load) Differential Driver Output (With Load) Test Conditions R L = 27Ω (RS-485) (See Fig. 1) R L = 50Ω (RS-422) (See Fig. 1) Min. Typ. 1.5 Max. Unit 5 V 5 5 V V R L = 27Ω or 50Ω (See Fig. 1) 0.2 V R L = 27Ω or 50Ω (See Fig. 1) 3 V R L = 27Ω or 50Ω (See Fig. 1) 0.2 V VIH Change in Magnitude of Driver Differential Output Voltage for Complementary Output States Driver Common-Mode Output Voltage Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States Input High Voltage VOC ∆V OC RE, DE, DI 2.0 V VIL Input Low Voltage RE, DE, DI 0.8 V IIN1 Input Current RE, DE, DI ±2 µA IIN2 Input Current (A, B) V CM = 0V or 5.25V V IN = 12V V IN = -7V 1 -0.8 mA mA 0.2 V VTH ∆VTH VOH VOL IOZR R IN ICC VDE = 0V Receiver Differential Threshold Voltage Receiver Input Hysteresis V CM = -7 to 12V Receiver Output High Voltage Receiver Output Low Voltage 3-State (High Impedance) Output Current at Receiver Receiver Input Resistance IO = -4mA VID = 200mV IO = 4mA VID = -200mV No Load Supply Current (Note 2) -0.2 V CM = 0V 70 3.5 V V O = 0.4 to 2.4V V CM = -7 to 12V mV 0.4 V ±1 µA 24 V RE = 0V or VCC V DE = VCC V DE = 0V KΩ 400 300 900 500 µA µA IOSD1 Driver Short-Circuit Current, V O = -7 to 12V (Note 3) VO=High 35 250 mA IOSD2 Driver Short-Circuit Current, V O = -7 to 12V (Note 3) VO=Low 35 250 mA IOSR Receiver Short-Circuit Current 7 95 mA V O = 0V to V CC 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: Supply current specification is valid for loaded transmitters when VDE = 0V Note 3: Applies to peak current. See typical Operating Characteristics. 3/12 ST485 DRIVER SWITCHING CHARACTERISTICS (VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) (See Note 1) Symbol Parameter tPLH tPHL Propagation Delay Input to Output tSK Output Skew to Output (See Fig. 3 and 5) R DIFF = 54Ω CL1 = CL2 = 100pF tTLH tTHL Rise or Fall Time (See Fig. 3 and 5) R DIFF = 54Ω CL1 = CL2 = 100pF tPZH Output Enable Time tPZL tPLZ tPHZ Output Enable Time Output Disable Time Output Disable Time Test Conditions R DIFF = 54Ω Min. Typ. Max. Unit 10 30 60 ns 5 10 ns 15 40 ns S2 = Closed 70 90 ns S1 = Closed 70 90 ns S1 = Closed 70 90 ns S2 = Closed 70 90 ns CL1 = CL2 = 100pF (See Fig. 3 and C L = 100pF (See Fig. 4 and C L = 100pF (See Fig. 4 and CL = 15pF (See Fig. 4 and CL = 15pF (See Fig. 4 and 3 5) 6) 6) 6) 6) 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. RECEIVER SWITCHING CHARACTERISTICS (VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) (See Note 1) Symbol Parameter tPLH tPHL Propagation Delay Input to Output R DIFF = 54Ω CL1 = CL2 = 100pF (See Fig. 3 and 7) tSKD Differential Receiver Skew RDIFF = 54Ω (See Fig. 3 and C RL = 15pF (See Fig. 2 and C RL = 15pF (See Fig. 2 and CRL = 15pF (See Fig. 2 and CRL = 15pF (See Fig. 2 and tPZH tPZL tPLZ tPHZ fMAX Output Enable Time Output Enable Time Output Disable Time Output Disable Time Maximum Data Rate Test Conditions Min. Typ. Max. Unit 20 130 210 ns CL1 = CL2 = 100pF 13 ns S1 = Closed 20 50 ns S2 = Closed 20 50 ns S1 = Closed 20 50 ns S2 = Closed 20 50 ns 7) 8) 8) 8) 8) 2.5 Mbps 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. 4/12 ST485 TEST CIRCUITS AND TYPICAL CHARACTERISTICS Figure 1 : Driver DC Test Load Figure 3 : Drive/Receiver Timing Test Circuit Figure 2 : Receiver Timing Test Load Figure 4 : Driver Timing Test Load 5/12 ST485 Figure 5 : Driver Propagation Delay Figure 6 : Driver Enable and Disable Time 6/12 ST485 Figure 7 : Receiver Propagation Delay Figure 8 : Receiver Enable and Disable Time 7/12 ST485 Figure 9 : Receiver Output Current vs Output Low Voltage Figure 12 : Driver Output Current vs Output High Voltage Figure 10 : Receiver Output Current vs Output High Voltage Figure 13 : Supply Current vs Temperature Figure 11 : Driver Output Current vs Output Low Voltage Figure 14 : Receiver High Level Output Voltage vs Temperature 8/12 ST485 Figure 15 : Receiver Low Level Output Voltage vs Temperature Figure 16 : Differential Driver Output Voltage vs Temperature 9/12 ST485 Plastic DIP-8 MECHANICAL DATA mm. inch DIM. MIN. A TYP MAX. MIN. 3.3 TYP. MAX. 0.130 a1 0.7 B 1.39 1.65 0.055 0.065 B1 0.91 1.04 0.036 0.041 b b1 0.028 0.5 0.38 0.020 0.5 D 0.015 0.020 9.8 0.386 E 8.8 0.346 e 2.54 0.100 e3 7.62 0.300 e4 7.62 0.300 F 7.1 0.280 I 4.8 0.189 L Z 3.3 0.44 0.130 1.6 0.017 0.063 P001F 10/12 ST485 SO-8 MECHANICAL DATA DIM. mm. MIN. TYP A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.25 a2 MAX. 0.003 0.009 1.65 0.064 a3 0.65 0.85 0.025 0.033 b 0.35 0.48 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.25 0.5 0.010 0.019 c1 45° (typ.) D 4.8 5.0 0.189 0.196 E 5.8 6.2 0.228 0.244 e 1.27 e3 0.050 3.81 0.150 F 3.8 4.0 0.149 0.157 L 0.4 1.27 0.015 0.050 M S 0.6 0.023 8° (max.) 0016023 11/12 ST485 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 f rom 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 2001 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 - Malt a - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom - United States. http://www.st.com 12/12