ST485EB ST485EC - ST485EX ±15 kV ESD protected, low power RS-485/RS-422 transceiver Features ■ Low quiescent current: 300 µA ■ Designed for RS-485 interface application ■ - 7 V to 12 V common mode input voltage range ■ Driver maintains high impedance in 3-state or with the power OFF ■ 70 mV typical input hysteresis SO-8 ■ 30 ns propagation delay, 5 ns skew ■ Operates from a single 5 V supply ■ Current limiting and thermal shutdown for Driver is short-circuit current limited and is driver overload protection protected against excessive power dissipation by ■ ESD protection: thermal shutdown circuitry that place the driver outputs into a high-impedance state. – ± 15 kV (HBM) – ± 8 kV (IEC-1000-4-2 contact discharge) The ST485E is designed for bi-directional data ■ Allows up to 256 transceivers on the bus communications on multipoint bus transmission lines (half-duplex applications). Description The ST485E is a low power transceiver for RS- 485 and RS-422 communication. Each driver output and receiver input is protected against ± 15 kV electrostatic discharge (HBM) (ESD) shocks, without latch-up. These parts contain one driver and one receiver in half duplex configuration. This transceiver draws 300 µA (typ.) of supply current when unloaded or fully loaded with disabled drivers. It operates from a single 5 V supply. Table 1. Device summary Temperature Order codes Package Packaging range ST485EBD - 40 to 85 °C SO-8 (tube) 100 parts per tube / 20 tube per box ST485ECDR 0 to 70 °C SO-8 (tape and reel) 2500 parts per reel ST485EBDR - 40 to 85 °C SO-8 (tape and reel) 2500 parts per reel ST485EXDR - 55 to 125 °C SO-8 (tape and reel) 2500 parts per reel February 2009 Rev 14 1/18 www.st.com 18

Contents ST485EB - ST485EC - ST485EX Contents 1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Truth tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Test circuit and typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2/18

ST485EB - ST485EC - ST485EX Pin configuration 1 Pin configuration Figure 1. Pin connections (top view) Table 2. 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 Ground 6 A Non-inverting receiver input and non-inverting driver output 7 B Inverting receiver input and inverting driver output 8 V Supply voltage CC 3/18

Truth tables ST485EB - ST485EC - ST485EX 2 Truth tables Table 3. 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 4. Truth table (receiver) Inputs Outputs RE DE A-B RO L L ≥ +0.2V H L L ≤ -0.2V L L L Inputs open H H L X Z Note: X = Don’t care; Z = High impedance 4/18

ST485EB - ST485EC - ST485EX Maximum ratings 3 Maximum ratings Table 5. Absolute maximum ratings Symbol Parameter Value Unit V Supply voltage 7 V CC V Control input voltage (RE, DE) -0.5 to (V + 0.5) V I CC V Driver input voltage (DI) -0.5 to (V + 0.5) V DI CC V Driver output voltage (A, B) ± 14 V DO V Receiver input voltage (A, B) ± 14 V RI V Receiver output voltage (RO) -0.5 to (V + 0.5) V RO CC Note: Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these is not implied. 5/18

Electrical characteristics ST485EB - ST485EC - ST485EX 4 Electrical characteristics Table 6. ESD performance: transmitter outputs, receiver inputs Symbol Parameter Test conditions Min. Typ. Max. Unit ESD ESD protection voltage Human body model ±15 kV ESD ESD protection voltage IEC-1000-4-2 ±8 kV V = 5 V ± 5 %, T = T to T , unless otherwise specified. Typical values are referred CC A MIN MAX to T = 25 °C A Table 7. D C electrical characteristics Symbol Parameter Test conditions (1) Min. Typ. Max. Unit Differential driver output (no V 5 V OD1 load) Differential driver output R = 27 Ω (RS-485) (Figure2) 5 V V L 1.5 OD2 (with load) R = 50 Ω (RS-422) (Figure 2.) 5 V L Change in magnitude of driver differential output ΔV R = 27 Ω or 50 Ω (Figure2) 0.2 V OD voltage for complementary L output states Driver common-mode output V R = 27 Ω or 50 Ω (Figure2) 3 V OC voltage L Change in magnitude of driver common-mode output ΔV R = 27 Ω or 50 Ω (Figure2) 0.2 V OC voltage for complementary L output states V Input high voltage RE, DE, DI 2.0 V IH V Input low voltage RE, DE, DI 0.8 V IL I Input current RE, DE, DI ± 2 µA IN1 V = 0 V or 5.25 V, V = 0 V CM DE I Input current (A, B) V = 12 V 1 mA IN2 IN V = -7 V -0.8 mA IN Receiver differential V V = -7 to 12 V -0.2 0.2 V TH threshold voltage CM ΔV Receiver input hysteresis V = 0 V 70 mV TH CM V Receiver output high voltage I = -4 mA, V = 200 mV 3.5 V OH O ID V Receiver output low voltage I = 4 mA, V = -200 mV 0.4 V OL O ID 3-State (high impedance) I V = 0.4 to 2.4 V ± 1 µA OZR output current at receiver O R Receiver input resistance V = -7 to 12 V 96 kΩ IN CM V = 0V or V RE CC I No load supply current (2) V = V 400 900 µA CC DE CC V = 0 V 300 500 µA DE 6/18

ST485EB - ST485EC - ST485EX Electrical characteristics Table 7. DC electrical characteristics (continued) Symbol Parameter Test conditions (1) Min. Typ. Max. Unit Driver short-circuit current, I V = -7 to 12 V (3) 35 250 mA OSD1 V =High O O Driver short-circuit current, I V = -7 to 12 V (3) 35 250 mA OSD2 V =Low O O I Receiver short-circuit current V = 0 V to V 7 95 mA OSR O CC 1. All currents into device pins are positive; all 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 V = 0 V DE 3. Applies to peak current. See typical Operating Characteristics. V = 5 V ± 5 %, T = T to T , unless otherwise specified. Typical values are referred CC A MIN MAX to T = 25 °C A Table 8. D river switching characteristics Symbol Parameter Test conditions (1) Min. Typ. Max. Unit t Propagation delay input to R = 54 Ω, C = C = 100 pF PLH DIFF L1 L2 25 45 ns t output (See Figure4 and Figure6) PHL R = 54 Ω, C = C = 100 pF t Output skew to output DIFF L1 L2 2 5 ns SK (See Figure4 and Figure6) t R = 54 Ω, C = C = 100 pF TLH Rise or fall time DIFF L1 L2 15 40 ns t (See Figure4 and Figure6) THL C = 100 pF, S2 = Closed t Output enable time L 35 50 ns PZH (See Figure5 and Figure7) C = 100 pF, S1 = Closed t Output enable time L 25 40 ns PZL (See Figure5 and Figure7) C = 15 pF, S1 = Closed t Output disable time L 25 40 ns PLZ (See Figure5 and Figure7) C = 15 pF, S2 = Closed t Output disable time L 35 50 ns PHZ (See Figure5 and Figure7) 1. All currents into device pins are positive; all out of device pins are negative; all voltages are referenced to device ground unless specified. 7/18

Electrical characteristics ST485EB - ST485EC - ST485EX V = 5 V ± 5%, T = T to T , unless otherwise specified. Typical values are referred CC A MIN MAX to T = 25 °C A Table 9. R e ceiver switching characteristics Symbol Parameter Test conditions (1) Min. Typ. Max. Unit t Propagation delay input to R = 54 Ω, C = C = 100 pF PLH DIFF L1 L2 110 130 ns t output (See Figure4 and Figure8) PHL R = 54 Ω, C = C = 100 pF t Differential receiver skew DIFF L1 L2 5 10 ns SKD (See Figure4 and Figure8) C = 15 pF, S1 = Closed t Output enable time RL 11 35 ns PZH (See Figure2 and Figure9) C = 15 pF, S2 = Closed t Output enable time RL 13 35 ns PZL (See Figure2 and Figure9) C = 15 pF, S1 = Closed t Output disable time RL 13 35 ns PLZ (See Figure2 and Figure9) C = 15 pF, S2 = Closed t Output disable time RL 11 35 ns PHZ (See Figure2 and Figure9) f Maximum data rate 5 Mbps MAX 1. All currents into device pins are positive; all out of device pins are negative; all voltages are referenced to device ground unless specified 8/18

ST485EB - ST485EC - ST485EX 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 9/18

Test circuit and typical characteristics ST485EB - ST485EC - ST485EX Figure 6. Driver propagation delay Figure 7. Driver enable and disable time 10/18

ST485EB - ST485EC - ST485EX Test circuit and typical characteristics Figure 8. Receiver propagation delay Figure 9. Receiver enable and disable time 11/18

Test circuit and typical characteristics ST485EB - ST485EC - ST485EX Figure 10. Receiver output current vs. output Figure 11. Receiver output current vs. output low voltage 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 Figure 15. Receiver high level output voltage vs. temperature 12/18

ST485EB - ST485EC - ST485EX Test circuit and typical characteristics Figure 16. Receiver low level output voltage Figure 17. Differential driver output voltage vs. vs. temperature temperature 13/18

Package mechanical data ST485EB - ST485EC - ST485EX 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK is an ST trademark. 14/18

ST485EB - ST485EC - ST485EX Package mechanical data SO-8 mechanical data mm. inch. Dim. Min. Typ. 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 8° (max.) ddd 0.1 0.04 0016023/C 15/18

Package mechanical data ST485EB - ST485EC - ST485EX Tape & reel SO-8 mechanical data mm. inch. Dim. Min. Typ. Max. Min. Typ. Max. A 330 12.992 C 12.8 13.2 0.504 0.519 D 20.2 0.795 N 60 2.362 T 22.4 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 16/18

ST485EB - ST485EC - ST485EX Revision history 7 Revision history Table 10. Document revision history Date Revision Changes 21-Mar-2006 9 Order codes has been updated and new template. 05-Jun-2006 10 Change value row 10 on the features and R in Table7. IN 29-Jan-2007 11 Typo mistake on page 1. 29-Aug-2007 12 Change value R min. on Table7. IN 07-Feb-2008 13 Modified: Table1 on page1. 16-Feb-2009 14 Modified: Note: on page 5. 17/18

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Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: S TMicroelectronics: ST485ECDR ST485EBDR ST485EXDR ST485EBN ST485ECN ST485EXD ST485EBD