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Technical content

Features

 Exceeds Requirements of EIA-485 Standard  Bus-Polarity Correction within 100 ms (tFS)  Data Rate: 300 bps to 250 kbps  Works with Two Configurations: – Failsafe Resistors Only – Failsafe and Differential Termination Resistors  Up to 256 Nodes on a Bus (1/8 unit load)  Wide Supply Voltage 3V to 5.5V  SOIC-8 Package for Backward Compatibility  Bus-Pin Protection: – ±18 kV HBM protection – ±13 kV IEC61000-4-2 Contact Discharge – +4 kV IEC61000-4-4 Fast Transient Burst

Applications

 E-Metering Networks  Industrial Automation  HVAC Systems  Process Control  DMX512-Networks  Battery-Powered Applications Pin Configuration (Top View) TP485E 8-Pin SOIC/MSOP -S and -V Suffixes R DE RE GND A/Y B/Z D VCC

Description

The TP485E is a low-power RS-485 transceiver with automatic bus-polarity correction and transient protection. Upon hot plug-in, the device detects and corrects the bus polarity within the first 100 ms of bus idling. On-chip transient protection protects the device against IEC61000 ESD and EFT transients. This device has robust drivers and receivers for demanding industrial applications. The bus pins are robust to electrostatic discharge (ESD) events, with high levels of protection to Human-Body Model (HBM), Air-Gap Discharge, and Contact Discharge specifications. The device combines a differential driver and a differential receiver, which operate together from a single 5-V power supply. The driver differential outputs and the receiver differential inputs are connected internally to form a bus port suitable for half-duplex(two-wire bus) communication. The device features a wide common-mode voltage range making the device suitable fo r multi-point applications over long cable runs. The TP485E is available in both SOIC-8 and MSOP-8 package, and is characterized from –40°C to 125°C. 3PEAK and the 3PEAK logo are registered trademarks of 3PEAK INCORPORATED. All other trademarks are the property of their respective owners.

2 R e v . A w w w . 3 p e a k i c . c o m TP485E ±18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver Order Information Model Name Order Number Package Transport Media, Quantity Marking Information TP485E TP485E-SR 8-Pin SOIC Tape and Reel, 4,000 TP485E TP485E TP485E-VR 8-Pin MSOP Tape and Reel, 3,000 TP485E DRIVER PIN FUNCTIONS INPUT ENABLE OUTPUTS H H H L Actively drives bus High L H L H Actively drives bus Low X L Z Z Driver disabled X OPEN Z Z Driver disabled by default OPEN H H L Actively drives bus High POLARITY-CORRECTING MODE (1) H H L H Actively drives bus Low L H H L Actively drives bus High X L Z Z Driver disabled X OPEN Z Z Driver disabled by default OPEN H L H Actively drives bus Low (1) The polarity-correcting mode is entered when V ID < VIT– and t > tFS and DE = low. This state is latched when /RE turns from Low to High. RECEIVER PIN FUNCTIONS DIFFERENTIAL INPUT ENABLE OUTPUT VID = VA – VB /RE R NORMAL MODE VIT+ < VID L H Receive valid bus High VIT– < VID < VIT+ L ? Indeterminate bus state VID < VIT– L L Receive valid bus Low X H Z Receiver disabled X OPEN Z Receiver disabled Open, short, idle Bus L ? Indeterminate bus state POLARITY-CORRECTING MODE (1) VIT+ < VID L L Receive valid bus Low VIT– < VID < VIT+ L ? Indeterminate bus state VID < VIT– L H Receive polarity corrected bus High X H Z Receiver disabled X OPEN Z Receiver disabled Open, short, idle Bus L ? Indeterminate bus state (1) The polarity-correcting mode is entered when V ID < VIT– and t > tFS and DE = low. This state is latched when /RE turns from Low to High.

±18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver w w w . 3 p e a k i c . c o m R e v . A Absolute Maximum Ratings Input Voltages Input/Output Voltages A/Y, B/Z, A, B, Y, Z (Transient Pulse Through 100Ω, Short Circuit Duration Recommended Operating Conditions Note 2 Thermal Resistance, ΘJA (Typical) Note 1: Tested according to TIA/EIA-485-A, Section 4.2.6 (±100V for 15μs at a 1% duty cycle). Note 2: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty.

4 R e v . A w w w . 3 p e a k i c . c o m TP485E ±18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver

Electrical Characteristics

Test Conditions: VCC = 5V, Over operating free-air temperature range(unless otherwise noted) PARAMETER CONDITIONS MIN TYP MAX UNITS |VOD| Driver differential-output voltage magnitude RL = 60 Ω See Figure 1B 2.6 V RL = 54 Ω with V A or VB from –7 to +12 V, VCC = 5V (RS-485) See Figure 1A 2.4 2.6 RL = 54 Ω with VA or VB from -7 to +12 V, VCC = 3V (RS-485) 1.4 1.5 RL = 100 Ω(RS-422) 3 ⊿|VOD| Change in magnitude of driver differential-output voltage RL = 54 Ω, CL=50pF See Figure 1A -0.01 0 0.03 V VOC(SS) Steady-stage common-mode output voltage Center of two 27- Ω load resistors See Figure 1A Vcc/2- 0.2 VCC/2 Vcc/2 +0.2 V ⊿VOC Change in differential driver common-mode output voltage -0.2 0 0.2 mV VOC(PP) Peak-to-peak driver common-mode output voltage 500 COD Differential output capacitance 8 pF VIT+ Positive-going receiver differential-input voltage threshold 75 mV VIT- Negative-going receiver differential-input voltage threshold -75 mV VHYS (1) Receiver differential-input voltage threshold hysteresis (VIT+ – VIT– ) 150 mV VOH Receiver high-level output voltage IOH= -8 mA 4.64 4.65 4.66 V VOL Receiver low-level output voltage IOL= 8 mA 0.22 0.23 0.24 V II Driver input, driver enable and receiver enable input current 0.012 0.017 0.022 μA IOZ Receiver high-impedance output current VO = 0 V or VCC, /RE at VCC -0.003 0 0.01 μA |IOS| Driver short-circuit output current │IOS│ with VA or VB from –7 to +12 V 80 107 mA II Bus input current(driver disabled) VCC = 4.5 to 5.5 V or VCC = 0 V, DE at 0 V VI= 12 V 55 65 μA VI= -7 V -63 -50 ICC Supply current(quiescent) Driver and receiver enabled DE = V CC, /RE = GND, No LOAD 624 680 771 μA Driver enabled, receiver disabled DE = V CC, /RE = VCC, No LOAD 269 278 290 Driver disabled, receiver enabled DE = GND, /RE = VCC, No LOAD 458 500 546 Driver and receiver disabled DE = GND, /RE = VCC, D= Vcc No LOAD 0.017 0.15 0.177 Supply current(dynamic) See

±18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver w w w . 3 p e a k i c . c o m R e v . A Switching CHARACTERISTICS .3.3ms > bit time> 4μs(unless otherwise noted) PARAMETER CONDITIONS MIN TYP MAX UNITS DRIVER tr, tf Driver differential-output rise and fall times RL = 54 Ω, CL=50pF See Figure 2 620 ns tPHL, tPLH Driver propagation delay 340 tSK(P) Driver pulse skew, |tPHL – tPLH| 23 tPHZ, tPLZ Driver disable time See Figure 3 250 ns tPHZ, tPLZ Driver enable time Receiver enabled 562 ns Receiver disabled 562 RECEIVER tr, tf Receiver output rise and fall times CL=15 pF See Figure 5 12.4 ns tPHL, tPLH Receiver propagation delay time 960 tSK(P) Receiver pulse skew, |tPHL – tPLH| 40 tPHZ, tPLZ Receiver disable time 7 ns tPZL(1), tPZH(1) tPZL(2), tPZH(2) Receiver enable time Driver enabled See Figure 6 70 ns Driver disabled See Figure 6 989 tFS Bus failsafe time Driver disabled See Figure 6 88 100 107 ms

limits on the driver and receiver outputs and thermal shutdown circuitry to protect against excessive power dissipation. idle periods. It is preferable to locate the resistor pair in the bus master, as shown in Figure 7. Figure 7. Polarity Definition RS-485 control lines to the proper states.

FIGURE 8. HOT PLUG PERFORMANCE (TP485E) vs Competitor WITHOUT HOT PLUG CIRCUITRY protection structures (e.g., transient suppression diodes), and the associated, undesirable capacitive load they present. discharge currents than the HBM model. testing is less repeatable than contact testing, air discharge protection levels are inferred from the contact discharge test results.

Typical Performance Curves VCC = 5V, TA = +25°C; Unless Otherwise Specified. FIGURE 19. DRIVER A ND REC EIVER W AVEFO RMS

14 R e v . A w w w . 3 p e a k i c . c o m TP485E ±18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver D b E e θ C Package Outline Dimensions SO-8 (SOIC-8) Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A1 0.100 0.250 0.004 0.010 A2 1.350 1.550 0.053 0.061 b 0.330 0.510 0.013 0.020 C 0.190 0.250 0.007 0.010 D 4.780 5.000 0.188 0.197 E 3.800 4.000 0.150 0.157 E1 5.800 6.300 0.228 0.248 e 1.270 TYP 0.050 TYP L1 0.400 1.270 0.016 0.050 θ 0° 8° 0° 8°

±18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver w w w . 3 p e a k i c . c o m R e v . A Package Outline Dimensions MSOP-8 Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.800 1.200 0.031 0.047 A1 0.000 0.200 0.000 0.008 A2 0.760 0.970 0.030 0.038 b 0.30 TYP 0.012 TYP C 0.15 TYP 0.006 TYP D 2.900 3.100 0.114 0.122 e 0.65 TYP 0.026 E 2.900 3.100 0.114 0.122 E1 4.700 5.100 0.185 0.201 L1 0.410 0.650 0.016 0.026 θ 0° 6° 0° 6° e E D L1 L2 L R θ b