Datasheet

ManualsBrandsST ManualsDriversTransceiver, RS-485/RS-422, 3.6V, 2.2mA, SO-8

October 2017

DocID9102 Rev 11

1/24

This is information on a product in full production.

www.st.com

ST3485EB, ST3485EC,

ST3485EI, ST3485EIY

3.3 V powered, 15 kV ESD protected, up to 12 Mbps RS-485/

RS-422 transceiver

Datasheet - production data

Features

 ESD protection

 ±15 kV IEC 61000-4-2 air discharge

 ±8 kV IEC 61000-4-2 contact discharge

 Operate from a single 3.3 V supply - no

charge pump required

 Interoperable with 5 V logic

 1 µA low current shutdown mode max.

 Guaranteed 12 Mbps data rate

 -7 to 12 V common mode input voltage

range

 Half duplex versions available

 Industry standard 75176 pinout

 Current limiting and thermal shutdown for

driver overload protection

 Guaranteed high receiver output state for

floating inputs with no signal present

 Allow up to 64 transceivers on the bus

 Available in SO8 package

 Automotive grade (ST3485EIY)

Description

The ST3485EB/EC/EI/EIY device is ±15 kV ESD

protected, 3.3 V low power transceiver for RS-

485 and RS-422 communications. The device

contains one driver and one receiver in half

duplex configuration.

The ST3485E device transmits and receives at a

guaranteed data rate of at least 12 Mbps.

All transmitter outputs and receiver inputs are

protected to ±15 kV IEC 61000-4-2 air discharge.

The driver is short-circuit current limited and is

protected against excessive power dissipation by

thermal shutdown circuitry that places the driver

outputs into a high impedance state.

Table 1: Device summary

Order code

Temp. range

Package

Packing

ST3485ECDR

0 to 70 °C

SO8 (tape and reel)

2500 parts per reel

ST3485EBDR

-40 to 85 °C

ST3485EIDT

-40 to 125 °C

ST3485EIYDT

Summary of content (24 pages)

PAGE 1
ST3485EB, ST3485EC, ST3485EI, ST3485EIY 3.
PAGE 2
Contents ST3485EB, ST3485EC, ST3485EI, ST3485EIY Contents 1 Pin configuration ............................................................................. 3 2 Truth tables ...................................................................................... 4 3 Maximum ratings ............................................................................. 5 4 5 Electrical characteristics ................................................................ 6 Test circuits and typical characteristics ...
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY 1 Pin configuration Pin configuration Figure 1: Pin connections RO 1 8 VCC RE 2 7 B DE 3 6 A DI 4 5 GND Table 2: Pin description Pin n° Symbol 1 RO 2 RE Name and function Receiver output. If A > B by 200 mV, RO will be high; if A < B by 200 mV, RO will be low. Receiver output enable. RO is enabled when RE impedance when RE is low; RO is high is high. If RE is high and DE is low, the device will enter a low power shutdown mode.
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Truth tables 2 ST3485EB, ST3485EC, ST3485EI, ST3485EIY Truth tables Table 3: Truth table (driver) Inputs Outputs Mode RE DE X H L H L DI B A H L H L H L X Z Z Normal Shutdown Note: X = “don’t care”; Z = high impedance Table 4: Truth table (receiver) Inputs RE L H Output Mode DE L A-B RO ≥ 0.2 V H ≤ -0.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY 3 Maximum ratings Maximum ratings Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. Table 5: Absolute maximum ratings Symbol VCC Parameter Value Supply voltage Unit 7 VI Control input voltage ( RE , DE) -0.3 to 7 VDI Driver input voltage (DI) -0.
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Electrical characteristics 4 ST3485EB, ST3485EC, ST3485EI, ST3485EIY Electrical characteristics Table 6: Electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = 40 to 85 °C for ST3485EBDR, TA = -40 to 125 °C for ST3485EIDT and ST3485EIYDT, unless otherwise specified. Typical values are referred to TA = 25 °C) Symbol Parameter Test conditions Min. Typ. Max. 1.3 2.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Electrical characteristics Table 8: Transmitter electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for ST3485EBDR, TA = -40 to 125 °C for ST3485EIDT and ST3485EIYDT, unless otherwise specified. Typical values are referred to TA = 25 °C) Symbol VOD Parameter Differential drive output Test conditions Min. RL= 100 Ω (RS-422) (Figure 2) 2 RL= 54 Ω (RS-485) (Figure 2) 1.5 RL= 60 Ω (RS-485) (Figure 3) 1.5 Typ.
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Electrical characteristics ST3485EB, ST3485EC, ST3485EI, ST3485EIY Table 10: Driver switching characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for ST3485EBDR, TA = -40 to 125 °C for ST3485EIDT and ST3485EIYDT, unless otherwise specified. Typical values are referred to TA = 25 °C) Symbol Parameter Test conditions Min. Typ. 12 15 Max.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Electrical characteristics Table 11: Receiver switching characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for ST3485EBDR, TA = -40 to 125 °C for ST3485EIDT and ST3485EIYDT, unless otherwise specified. Typical values are referred to TA = 25 °C) Symbol Parameter Test conditions Min. Typ. Max.
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Test circuits and typical characteristics 5 ST3485EB, ST3485EC, ST3485EI, ST3485EIY Test circuits and typical characteristics Figure 2: Driver and VOC test load RL 2 D VOD RL 2 VCC VOC Figure 3: Driver VOD with varying common mode voltage test load 375 Ω VCM = -7 to 12 V D VOD RL VCC 375 Ω Figure 4: Receiver VOH and VOL test circuit VID 0V 10/24 R VOL DocID9102 Rev 11 IOL (+) VOH IOL (-)
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Test circuits and typical characteristics Figure 5: Drive differential output delay transition time test circuit IN (1) OUT D CL VCC 1. 2. RL = 60 Ω CL = 15 pF (2) The input pulse is supplied by a generator with the following characteristics: PRR = 250 kHz, 50 % duty cycle, tr ≤ 6.0 ns, ZO = 50 Ω. CL includes probe and stray capacitance Figure 6: Drive differential output delay transition time waveform 3V IN 1.5 V 1.
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Test circuits and typical characteristics ST3485EB, ST3485EC, ST3485EI, ST3485EIY Figure 8: Drive enable and disable times waveforms (pull-down configuration) 3V IN 1.5 V 1.5 V 0V tPZH or tPSH tPHZ (1) 0.25 V OUT VOH VOM 0V 1. tPZH is valid if the driver is initially disabled ( RE is high), tPSH is valid if the driver is initially in shutdown mode (RE is low). Figure 9: Drive propagation time test circuit VOM = (VOH = VOL)/2 = 1.5 V RL = 27 Ω S1 IN (1) OUT D CL = 15 pF (2) VCC 1. 2.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Test circuits and typical characteristics Figure 10: Drive propagation time waveform 3V IN 1.5 V 1.5 V 0V t PLH t PHL VOH OUT A VOM VOM VOL t PHL t PLH VOH VOM OUT B VOM VOL Figure 11: Drive enable and disable times test circuit (pull-up configuration) VCC RL = 110 Ω S1 0 V or 3 V IN 1. 2. OUT D (2) CL = 50 pF (1) The input pulse is supplied by a generator with the following characteristics: PRR = 250 kHz, 50 % duty cycle, tr ≤ 6.0 ns.
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Test circuits and typical characteristics ST3485EB, ST3485EC, ST3485EI, ST3485EIY Figure 12: Drive enable and disable times waveforms (pull-up configuration) 3V IN 1.5 V 1.5 V 0V t PLZ (1) tPZL or tPSL VCC OUT VOM 0.25 V 1. VOL tPZL is valid if the driver is initially disabled ( RE is high), tPSL is valid if the driver is initially in shutdown mode (RE is low). Figure 13: Receiver propagation delay time test circuit IN (1) VID R OUT CL = 1.5 pF (2) 1.5 V 0V 1. 2.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Test circuits and typical characteristics Figure 14: Receiver propagation delay time waveforms 3.0 V IN 1.5 V 1.5 V 0V t RPLH t RPHL VCC OUT VOM VOM VOM = VCC/2 0V Figure 15: Receiver enable and disable times test circuit OUT 1.5 V S3 S1 1 kΩ -1.5 V VID R VCC S2 (2) CL (1) IN 1. 2. The input pulse is supplied by a generator with the following characteristics: PRR = 250 kHz, 50 % duty cycle, tr ≤ 6.0 ns.
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Test circuits and typical characteristics ST3485EB, ST3485EC, ST3485EI, ST3485EIY Figure 16: Receiver enable and disable times waveform (test 1) 3V IN 1.5 V S1 open S2 closed S3 = 1.5 V 0V t PRZH t PRSH VOH OUT 1.5 V 0V Figure 17: Receiver enable and disable times waveform (test 2) 3V IN 1.5 V S1 closed S2 open S3 = -1.5 V 0V t PRZL t PRSL VCC 1.5 V OUT VOL Figure 18: Receiver enable and disable times waveform (test 3) 3V 1.5 V IN S1 open S2 closed S3 = 1.5 V 0V t PRHZ VOH - 0.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Test circuits and typical characteristics Figure 19: Receiver enable and disable times waveform (test 4) 3V IN 1.5 V S1 closed S2 open S3 = -1.5 V 0V t PRLZ VCC OUT 0.25 V VOL Figure 20: Receiver output current vs. output low voltage Figure 21: Receiver output current vs.
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Test circuits and typical characteristics ST3485EB, ST3485EC, ST3485EI, ST3485EIY Figure 24: Receiver input characteristics Figure 25: Driver short-circuit current (test 1) Figure 26: Driver short-circuit current (test 2) 18/24 DocID9102 Rev 11
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY 6 Package information Package information 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. 6.1 SO8 package information Figure 27: SO8 package outline Table 12: SO8 mechanical data Dimensions Ref. Millimeters Min. Typ.
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Package information 6.2 ST3485EB, ST3485EC, ST3485EI, ST3485EIY SO8 tape and reel information Figure 28: SO8 tape and reel outline 1. Drawing not to scale Table 13: SO8 tape and reel mechanical data Dimensions Symbol mm Min. Typ. A Max. Min. Typ. 330 C 12.8 D 20.2 N 60 T 20/24 Inches Ao 8.1 Bo 13.2 Max. 12.992 0.504 0.519 0.795 2.362 — 22.4 — 0.882 8.5 0.319 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.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY 7 Ordering information Ordering information Table 14: Order codes Order code Temperature range ST3485ECDR 0 to 70 °C ST3485EBDR -40 to 85 °C ST3485EIDT -40 to 125 °C ST3485EIYDT(1) Package Packaging Marking 3485EC SO8 -40 to 125 °C (automotive grade) Tape and reel 3485EB 3485EI 3485EIY Notes: (1)Qualification and characterization according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001 and Q 002 or equivalent.
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Revision history 8 ST3485EB, ST3485EC, ST3485EI, ST3485EIY Revision history Table 15: Document revision history Date Revision 20-Jun-2005 2 Mistake on table 12 tZL(SHDN) ms ==> µs. 30-Aug-2005 3 Remove (TRUE) on title, description has been updated in cover page. The VTH and DVTH values are changed in table 10. 07-Apr-2006 4 Order codes updated. 12-Nov-2007 5 Added Table 1.
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY Date Revision 26-Oct-2017 11 Revision history Changes Updated Figure 20: "Receiver output current vs. output low voltage", Figure 21: "Receiver output current vs. output high voltage", Figure 24: "Receiver input characteristics" and Figure 26: "Driver short-circuit current (test 2)".
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ST3485EB, ST3485EC, ST3485EI, ST3485EIY IMPORTANT NOTICE – PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement.