ST485 Low power RS-485/RS-422 transceiver General features ■ Low quiescent current: 300mA ■ Designed for RS-485 interface application ■ -7V to 12V common mode input voltage range ■ Driver maintains high impedance in 3-state or with the power OFF ■ 70mV tipycal input hysteresis ■ 30ns propagation delay, 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 DIP-8 Description SO-8 The ST485 is al low power transceiver for RS-485 and RS-422 communication. Each part contains one driver and one receiver. 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. This transceiver draw 300mA (typ.) of supply current when unloaded or fully loaded with disabled drivers. The ST485 is designed for bi-directional data communications on multipoint bus transmission line (half-duplex applciations). It operates from a single 5V supply. The ST485 is available in three temperature range: commercial (0°C to 70°C), industrial (40°C to 850°C) and automotive (-55°C to 125°C) Order code Part number Temperature range Package Comments ST485CN 0 to 70 °C DIP-8 50parts per tube / 40tube per box ST485BN -40 to 85 °C DIP-8 50parts per tube / 40tube per box ST485XN -55 to 125 °C DIP-8 50parts per tube / 40tube per box ST485CD 0 to 70 °C SO-8 (Tube) 100parts per tube / 20tube per box ST485BD -40 to 85 °C SO-8 (Tube) 100parts per tube / 20tube per box ST485CDR 0 to 70 °C SO-8 (Tape & reel) 2500 parts per reel ST485BDR -40 to 85 °C SO-8 (Tape & reel) 2500 parts per reel ST485XDR -55 to 125 °C SO-8 (Tape & reel) 2500 parts per reel March 2006 Rev 12 1/19 www.st.com 19 Contents ST485 Contents 1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Truth tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1 Driver switching characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.2 Receiver switching characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 Test circuit and typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2/19 ST485 1 Pin configuration Pin configuration Figure 1. 1.1 Pin configuration Pin description Table 1. Pin description Pin n° Symbol Name and function 1 RO Receiver Output 2 RE Receiver Output Enable 3 DE Driver Output Enable 4 DI Driver Input 5 GND 6 A Non-inverting Receiver Input and Non-inverting Driver Output 7 B Inverting Receiver Input and Inverting Driver Output 8 VCC Ground Supply Voltage 3/19 Truth tables ST485 2 Truth tables Table 2. Truth table (driver) Inputs Outputs RE DE DI B A X H H L H X H L H L X L X Z Z Note: X = Don’t care; Z = High impedance Table 3. Truth table (receiver) Inputs Note: 4/19 Outputs RE DE A-B L L ≥ +0.2V H L L ≤ -0.2V L L L INPUTS OPEN H H L X Z X = Don’t care; Z = High impedance RO ST485 Maximum ratings 3 Maximum ratings Table 4. Absolute maximum ratings Symbol VCC Parameter Supply Voltage Value Unit 7 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 VDO Driver Output Voltage (A, B) ± 14 V VRI Receiver Input Voltage (A, B) ± 14 V VRO Receiver Output Voltage (RO) -0.5 to (VCC + 0.5) V Note: Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. V+ and V- can have a maximum magnitude of +7V, but their absolute addition can not exceed 13 V. 5/19 Electrical characteristics 4 ST485 Electrical characteristics VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) Table 5. DC Electrical characteristics Value Symbol Parameter Test conditions (1) -40 to 85 °C Min VOD1 Differential Driver Output (No Load) VOD2 Differential Driver Output RL = 27Ω (RS-485) (Figure 2.) (With Load) RL = 50Ω (RS-422) (Figure 2.) ∆VOD Change in Magnitude of Driver Differential Output RL = 27Ω or 50Ω (Figure 2.) Voltage for Complementary Output States Typ -55 to 125 °C Max Min 5 Max 5 V 5 5 V V 0.2 0.2 V 5 5 1.5 Unit 1.4 Driver Common-Mode Output Voltage RL = 27Ω or 50Ω (Figure 2.) 3 3 V Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States RL = 27Ω or 50Ω (Figure 2.) 0.2 0.2 V VIH Input High Voltage RE, DE, DI VIL Input Low Voltage RE, DE, DI 0.8 0.8 V IIN1 Input Current RE, DE, DI ±2 ±2 µA IIN2 Input Current (A, B) VCM = 0V or 5.25VVDE = 0V VIN = 12V VIN = -7V 1 -0.8 1 -0.8 mA mA VTH Receiver Differential Threshold Voltage VCM = -7 to 12V 0.2 V ∆VTH Receiver Input Hysteresis VCM = 0V VOH Receiver Output High Voltage IO = -4mAVID = 200mV VOL Receiver Output Low Voltage IO = 4mAVID = -200mV 0.4 0.55 V IOZR 3-State (High Impedance) Output Current at Receiver VO = 0.4 to 2.4V ±1 ±1 µA RIN Receiver Input Resistance VCM = -7 to 12V VOC ∆VOC 6/19 2.0 2.0 -0.2 0.2 -0.2 V 70 mV 3.5 24 3.4 24 V KW ST485 Electrical characteristics Table 5. DC Electrical characteristics Value Symbol Parameter Test conditions (1) -40 to 85 °C Min -55 to 125 °C Typ Max 400 300 900 500 (2) VRE = 0V or V CC VDE = VCC VDE = 0V IOSD1 Driver Short-Circuit Current, VO=High VO = -7 to 12V (3) 35 250 IOSD2 Driver Short-Circuit Current, VO=Low VO = -7 to 12V (3) 35 IOSR Receiver Short-Circuit Current VO = 0V to V CC 7 ICC No Load Supply Current Min Unit Max 900 500 µA µA 35 250 mA 250 35 250 mA 95 7 95 mA 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. 2. Supply current specification is valid for loaded transmitters when VDE = 0V 3. Applies to peak current. See typical Operating Characteristics. 4.1 Driver switching characteristics VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C Table 6. Driver switching characteristics Value Symbol Parameter Test conditions (1) -40 to 85 °C -55 to 125°C Min. Unit Min. Typ. Max. Max. 10 30 60 70 ns 5 10 10 ns 15 40 45 ns tPLH tPHL Propagation Delay Input to Output RDIFF = 54ΩCL1 = C L2 = 100pF (See Figure 4. and Figure 6.) tSK Output Skew to Output RDIFF = 54ΩCL1 = C L2 = 100pF (See Figure 4. and Figure 6.) tTLH tTHL Rise or Fall Time RDIFF = 54ΩCL1 = C L2 = 100pF (See Figure 4. and Figure 6.) tPZH Output Enable Time CL = 100pFS2 = Closed (See Figure 5. and Figure 7.) 70 90 90 ns tPZL Output Enable Time CL = 100pFS1 = Closed (See Figure 5. and Figure 7.) 70 90 90 ns tPLZ Output Disable Time CL = 15pFS1 = Closed (See Figure 5. and Figure 7.) 70 90 90 ns tPHZ Output Disable Time CL = 15pFS2 = Closed (See Figure 5. and Figure 7.) 70 90 90 ns 3 3 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. 7/19 Electrical characteristics 4.2 ST485 Receiver switching characteristics VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) Table 7. Receiver switching characteristics Value Symbol Parameter Test conditions (1) -40 to 85 °C -55 to 125°C Min. Typ. Max. 20 130 210 Min. Unit Max. tPLH tPHL Propagation Delay Input RDIFF = 54ΩCL1 = CL2 = 100pF to Output (See Figure 4. and Figure 8.) tSKD Differential Receiver Skew RDIFF = 54ΩCL1 = CL2 = 100pF (See Figure 4. and Figure 8.) 13 tPZH Output Enable Time CRL = 15pFS1 = Closed (See Fig. 2 and Figure 9.) 20 50 56 ns tPZL Output Enable Time CRL = 15pFS2 = Closed (See Fig. 2 and Figure 9.) 20 50 56 ns tPLZ Output Disable Time CRL = 15pFS1 = Closed (See Fig. 2 and Figure 9.) 20 50 56 ns tPHZ Output Disable Time CRL = 15pFS2 = Closed (See Fig. 2 and Figure 9.) 20 50 56 ns fMAX Maximum Data Rate 2.5 230 ns ns 2.5 Mbps 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 8/19 ST485 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. Drive/receiver timing test circuit Figure 5. Driver timing test load 9/19 Test circuit and typical characteristics 10/19 Figure 6. Driver propagation delay Figure 7. Driver enable and disable time ST485 ST485 Test circuit and typical characteristics Figure 8. Receiver propagation delay Figure 9. Receiver Enable and Disable Time 11/19 Test circuit and typical characteristics Figure 10. Receiver output current vs. output low voltage ST485 Figure 11. Receiver output current vs. output high voltage Figure 12. Driver output current vs. output low Figure 13. Driver output current vs. output voltage high voltage Figure 14. Supply current vs. temperature 12/19 Figure 15. Receiver high level output voltage vs. temperature ST485 Figure 16. Receiver low level output voltage vs. temperature Test circuit and typical characteristics Figure 17. Differential driver output voltage vs. temperature 13/19 Package mechanical data 6 ST485 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK® 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 ST485 Package mechanical data 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 15/19 Package mechanical data ST485 SO-8 MECHANICAL DATA DIM. mm. MIN. TYP inch MAX. MIN. TYP. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.04 0.010 A2 1.10 1.65 0.043 0.065 B 0.33 0.51 0.013 0.020 C 0.19 0.25 0.007 0.010 D 4.80 5.00 0.189 0.197 E 3.80 4.00 0.150 0.157 e 1.27 0.050 H 5.80 6.20 0.228 0.244 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 k ddd 8˚ (max.) 0.1 0.04 0016023/C 16/19 ST485 Package mechanical data Tape & Reel SO-8 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 8.1 8.5 0.319 0.335 Bo 5.5 5.9 0.216 0.232 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 17/19 Revision history ST485 7 Revision history Table 8. Revision history Date Revision 21-Mar-2006 12 18/19 Changes Order codes has been updated and new template. ST485 Please Read Carefully: Information in this document is provided solely in connection with ST products. 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