DATASHEET ±16.5kV ESD Protected, 16Mbps, with Active Low Rx EN, RS-485/422 Receiver ISL3282EMRTEP Features The Intersil ISL3282EMRTEP is a ±16.5kV IEC61000 ESD protected, 3.0V to 5.5V powered, single receiver that meets both the RS-485 and RS-422 standards for balanced communication. This receiver has very low bus currents (+125µA/-100µA), so it presents a true “1/8 unit load” to the RS-485 bus. This allows up to 256 receivers on the network without violating the RS-485 specification’s 32 unit load maximum and without using repeaters. • Specifications per DSCC VID V62/10601-01XB Receiver inputs feature a “Full Fail-Safe” design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or terminated but undriven. • Full traceability through assembly and test by date/trace code assignment The ISL3282EMRTEP includes an active low enable pin and is offered in the Military Temperature range (-55°C to +125°C). • Enhanced obsolescence management A 26% smaller footprint is available with the TDFN package. This device also features a logic supply pin (VL) that sets the VOH level of the RO output (and the switching points of the RE/RE input) to be compatible with another supply voltage in mixed voltage systems. Device Information The specifications for an Enhanced Product (EP) device are defined in a Vendor Item Drawing (VID), which is controlled by the Defense Supply Center in Columbus (DSCC). “Hot-links” to the applicable VID and other supporting application information are provided on our website. Applications • Full military temperature electrical performance from -55°C to +125°C • Controlled baseline with one wafer fabrication site and one assembly/test site • Full homogeneous lot processing in wafer fab • No combination of wafer fabrication lots in assembly • Enhanced process change notification • Eliminates need for up-screening a COTS component • ±16.5kV IEC61000 ESD protection on RS-485 inputs • Class 3 ESD level on all other pins. . . . . . . . . . . . . .>5kV HBM • Wide supply range . . . . . . . . . . . . . . . . . . . . . . . . . 3.0V to 5.5V • Specified for +125°C operation • Logic supply pin (VL) eases operation in mixed supply systems • Full fail-safe (open, short, terminated/undriven) • True 1/8 unit load allows up to 256 devices on the bus • High data rates. . . . . . . . . . . . . . . . . . . . . . . . . . up to 16Mbps • Low quiescent supply current. . . . . . . . . . 500µA (maximum) • Very low shutdown supply current . . . . . . . 20µA (maximum) • Clock distribution • -7V to +12V common-mode input voltage range • High node count systems • Tri-statable Rx available (active low or high EN input) • Space constrained systems • 5V tolerant logic inputs when VCC 5V • Security camera networks • Building environmental control/lighting systems • Industrial/process control networks TABLE 1. SUMMARY OF FEATURES PART NUMBER FUNCTION DATA RATE (Mbps) # DEVICES ON BUS RX ENABLE? VL PIN? QUIESCENT ICC (µA) LOW POWER SHUTDOWN? LEAD COUNT ISL3282EMRTEP 1 Rx 16 256 ACTIVE LOW YES 350 YES 8-TDFN June 17, 2016 FN7595.2 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2010, 2011, 2016. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. ISL3282EMRTEP Ordering Information PART NUMBER (Notes 1, 2) VENDOR ITEM DRAWING ISL3282EMRTEP-TK V62/10601-01XB PART MARKING 282 TEMP. RANGE (°C) TAPE AND REEL (UNITS) -55 to +125 1k PKG. DWG. # PACKAGE 8 Ld TDFN L8.2x3A NOTES: 1. Please refer to TB347 for details on reel specifications. 2. For Moisture Sensitivity Level (MSL), please see device information page for ISL3282EMRTEP. For more information on MSL please see techbrief TB363. Pin Configuration Truth Table ISL3282EMRTEP (8 LD TDFN) TOP VIEW RECEIVING INPUTS OUTPUT RE A-B RO 0 ≥ -0.05V RO 1 1 GND 2 0 ≤ -0.2V 0 NC 0 Inputs Open/Shorted 1 VCC 1 X High-Z* 8 B 7 RE 3 6 VL 4 5 A R Pin Descriptions PIN PIN NUMBER NAME FUNCTION 1 RO Receiver output: If A - B ≥ -50mV, RO is high; If A - B ≤ -200mV, RO is low; RO = High if A and B are unconnected (floating) or shorted. 7 RE Receiver output enable. RO is enabled when RE is low; RO is high impedance when RE is high. If the Rx enable function is not used, connect RE directly to GND. RE is internally pulled high. 2 GND Ground connection. This is also the potential of the TDFN thermal pad. 5 A ±16.5kV IEC61000 ESD Protected RS-485, RS-422 level, noninverting receiver input. 8 B ±16.5kV IEC61000 ESD Protected RS-485, RS-422 level, inverting receiver input. 4 VCC System power supply input (3.0V to 5.5V). On devices with a VL pin, power-up VCC first. 6 VL Logic-level supply, which sets the VIL/VIH levels for the RE pin, and sets the VOH level of the RO output. Power-up this supply after VCC, and keep VL ≤ VCC. 3 NC No Connection Submit Document Feedback 2 FN7595.2 June 17, 2016 ISL3282EMRTEP Typical Operating Circuits +3.3V TO 5V 1.8V +3.3V + 4 VCC 6 VL VCC 0.1µF 0.1µF 8 1 RO R 1 VCC ISL3282EMRTEP LOGIC DEVICE (µP, ASIC, UART) 2.5V + VCC VL ISL3298EMRTEP A 5 B 8 RT 6 Y 7 Z D 7 RE LOGIC DEVICE (mP, ASIC, UART) DI 3 DE 2 GND 2 GND 4, 5 FIGURE 1. NETWORK WITH VL PIN FOR INTERFACE TO LOWER VOLTAGE LOGIC DEVICES Test Circuits and Waveforms RE VCC GND B R A +1V B RE 0V 15pF RO 0V -1V A tPHL tPLH VCC OR VL SIGNAL GENERATORS 50% RO 50% 0V FIGURE 2A. TEST CIRCUIT FIGURE 2B. MEASUREMENT POINTS FIGURE 2. RECEIVER PROPAGATION DELAY AND DATA RATE RE GND 3V B A 1kΩ RO R VCC OR VL SW SIGNAL GENERATOR RE 1.5V 0V GND tZH 15pF OUTPUT HIGH PARAMETER A (V) SW tHZ +1.5 GND tLZ -1.5 VCC OR VL tZH +1.5 GND tZL -1.5 VCC OR VL tHZ VOH - 0.25V 50% RO FIGURE 3A. TEST CIRCUIT 1.5V VOH 0V tZL RO tLZ VCC OR VL 50% OUTPUT LOW VOL + 0.25V V OL FIGURE 3B. MEASUREMENT POINTS FIGURE 3. RECEIVER ENABLE AND DISABLE TIMES Submit Document Feedback 3 FN7595.2 June 17, 2016 ISL3282EMRTEP Application Information VCC = +3.3V TO 5V RS-485 and RS-422 are differential (balanced) data transmission standards for use in long haul or noisy environments. RS-422 is a subset of RS-485, so RS-485 transceivers are also RS-422 compliant. RS-422 is a point-to-multipoint (multidrop) standard, which allows only one driver and up to 10 (assuming one unit load devices) receivers on each bus. RS-485 is a true multipoint standard, which allows up to 32 one unit load devices (any combination of drivers and receivers) on each bus. Another important advantage of RS-485 is the extended Common-Mode Range (CMR), which specifies that the driver outputs and receiver inputs withstand signals that range from +12V to -7V. RS-422 and RS-485 are intended for runs as long as 4000’, so the wide CMR is necessary to handle ground potential differences, as well as voltages induced in the cable by external fields. Receiver Features This device utilizes a differential input receiver for maximum noise immunity and common-mode rejection. Input sensitivity is better than ±200mV, as required by the RS-422 and RS-485 specifications. Receiver input resistance of 96kΩ surpasses the RS-422 specification of 4kΩ and is eight times the RS-485 “Unit Load (UL)” requirement of 12kΩ minimum. Thus, these products are known as “one-eighth UL” transceivers and there can be up to 256 of these devices on a network while still complying with the RS-485 loading specification. Receiver inputs function with common-mode voltages as great as +9V/-7V outside the power supplies (i.e., +12V and -7V), making them ideal for long networks where induced voltages, and ground potential differences are realistic concerns. The ISL3282EMRTEP includes a “full fail-safe” function that guarantees a high level receiver output if the receiver inputs are unconnected (floating), shorted together, or connected to a terminated, however, undriven bus. Fail-safe with shorted inputs is achieved by setting the Rx upper switching point to -50mV, thereby ensuring that the Rx sees 0V differential as a high input level. The receiver can easily support a 16Mbps data rate, and its output is tri-statable via the active low RE input. TABLE 2. VIH, VIL AND DATA RATE vs VL FOR VCC = 3.3V OR 5V VL (V) VIH (V) VIL (V) DATA RATE (Mbps) 1.35 0.55 0.5 11 1.6 0.7 0.6 16 1.8 0.8 0.7 23 2.3 1 0.9 27 2.7 1.1 1 30 3.3 1.3 1.2 30 5.5 (i.e., VCC) 2 1.8 24 Submit Document Feedback 4 VCC = +2V VL RO RE VOH = 2V RXD VIH = 1V GND ISL3282EMRTEP VOH 2V ESD DIODE RXEN GND UART/PROCESSOR FIGURE 4. USING VL PIN TO ADJUST LOGIC LEVELS Wide Supply Range The ISL3282EMRTEP is designed to operate with a wide range of supply voltages from 3.0V to 5.5V. This device meets the RS-422 and RS-485 specifications over this full range. Logic Supply (VL Pin) Note: Power-up VCC before powering up the VL supply. The ISL3282EMRTEP includes a VL pin that powers the logic input (RE) and/or the Rx output. These pins interface with “logic” devices such as UARTs, ASICs and microcontrollers. Today, most of these devices use power supplies significantly lower than 3.3V, thus, a 3.3V output level from a 3.3V powered RS-485 IC might seriously overdrive and damage the logic device input. Similarly, the logic device’s low VOH might not exceed the VIH of a 3.3V or 5V powered RE input. Connecting the VL pin to the power supply of the logic device (as shown in Figure 4) limits the ISL3282EMRTEP’s Rx output VOH to VL (see Figures 7 through 11), and reduces the RE input switching point to a value compatible with the logic device’s output levels. Tailoring the logic pin input switching point and output levels to the supply voltage of the UART, ASIC, or microcontroller eliminates the need for a level shifter/translator between the two ICs. VL can be anywhere from VCC down to 1.35V, however, the input switching points may not provide enough noise margin when VL < 1.6V. Table 2 indicates typical VIH, VIL, and data rate values for various VL settings so the user can ascertain whether or not a particular VL voltage meets his/her needs. The quiescent, RO unloaded, VL supply current (IL) is typically less than 60µA for VL 3.3V, as shown in Figure 6 on page 6. ESD Protection All pins on the device include Class 3 (>4kV) Human Body Model (HBM) ESD protection structures, however, the RS-485 pins (receiver inputs) incorporate advanced structures allowing them to survive ESD events in excess of ±16.5kV HBM and ±16.5kV IEC61000. The RS-485 pins are particularly vulnerable to ESD damage because they typically connect to an exposed port on the exterior of the finished product. Simply touching the port pins, or connecting a cable, can cause an ESD event that might destroy unprotected ICs. These new ESD structures protect the device whether or not it is powered up, and without degrading the RS-485 common-mode range of -7V to +12V. This built-in ESD FN7595.2 June 17, 2016 ISL3282EMRTEP protection eliminates the need for board level protection structures (e.g., transient suppression diodes), and the associated, undesirable capacitive load they present. IEC61000-4-2 Testing The IEC61000 test method applies to finished equipment, rather than to an individual IC. Therefore, the pins most likely to suffer an ESD event are those that are exposed to the outside world (the RS-485 pins in this case) and the IC is tested in its typical application configuration (power applied) rather than testing each pin-to-pin combination. The lower current limiting resistor coupled with the larger charge storage capacitor yields a test that is much more severe than the HBM test. The extra ESD protection built into this device’s RS-485 pins allows the design of equipment meeting level 4 criteria without the need for additional board level protection on the RS-485 port. AIR-GAP DISCHARGE TEST METHOD For this test method, a charged probe tip moves toward the IC pin until the voltage arcs to it. The current waveform delivered to the IC pin depends on approach speed, humidity, temperature, etc., so it is difficult to obtain repeatable results. The A and B RS-485 pins withstand ±16.5kV air-gap discharges. CONTACT DISCHARGE TEST METHOD During the contact discharge test, the probe contacts the tested pin before the probe tip is energized, thereby eliminating the variables associated with the air-gap discharge. The result is a more repeatable and predictable test, however, equipment limits prevent testing devices at voltages higher than ±9kV. The ISL3282EMRTEP can survive ±9kV contact discharges on the RS-485 pins. Submit Document Feedback 5 Data Rate, Cables, and Terminations RS-485, RS-422 are intended for network lengths up to 4000’, however, the maximum system data rate decreases as the transmission length increases. Networks operating at 16Mbps are limited to lengths less than 100’, while a 250kbps network that uses slew rate limited transmitters can operate at that data rate over lengths of several thousand feet. Twisted pair is the cable of choice for RS-485, RS-422 networks. Twisted pair cables tend to pick up noise and other electromagnetically induced voltages as common-mode signals, which are effectively rejected by the differential receiver in these ICs. To minimize reflections, proper termination is imperative for high data rate networks. Short networks using slew rate limited transmitters need not be terminated, however, terminations are recommended unless power dissipation is an overriding concern. In point-to-point, or point-to-multipoint (single driver on bus) networks, the main cable should be terminated in its characteristic impedance (typically 120Ω) at the end farthest from the driver. In multireceiver applications, stubs connecting receivers to the main cable should be kept as short as possible. Multipoint (multidriver) systems require that the main cable be terminated in its characteristic impedance at both ends. Stubs connecting a transmitter or receiver to the main cable should be kept as short as possible. Low Power Shutdown Mode This BiCMOS receiver uses a fraction of the power required by its bipolar counterparts, and include a shutdown feature that reduces the already low quiescent ICC to a 20µA trickle. They enter shutdown whenever the receiver is disabled (RE = VCC). FN7595.2 June 17, 2016 ISL3282EMRTEP Typical Performance Curves CL = 15pF, TA = +25°C; unless otherwise specified. 440 250 VCC = 5V OR 3.3V VCC = VL = 5.5V 430 200 420 IL (mA) ICC (µA) 410 400 150 VL = 5V, VCC = 5V ONLY 100 VCC = VL = 3.3V 390 VL 1.8V 50 380 VL = 3.3V 370 -55 -35 -15 5 25 45 65 85 105 0 125 VL = 2.5V 0 1 2 3 TEMPERATURE (°C) FIGURE 5. SUPPLY CURRENT vs TEMPERATURE VOL, +25°C VOH, +25°C 40 VOL, +85°C VOL, +125°C VOH, +125°C 30 VOH, +85°C 20 10 0 VOL, +25°C 25 VOL, +125°C 20 15 VOH, +85°C VOH, +125°C 10 5 VCC = 5V OR 3.3V, VL = 3.3V 0 1 2 3 4 0 5 0 9 VCC = 5V OR 3.3V, VL = 2.5V 18 VOL, +25°C VOL, +85°C 16 14 VOL, +125°C 12 VOH, +25°C 10 8 VOH, +125°C 6 VOH, +85°C 4 2 0 0.5 1.0 1.5 2.0 2.5 RECEIVER OUTPUT VOLTAGE (V) FIGURE 9. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE Submit Document Feedback 6 1.0 1.5 2.0 2.5 3.0 3.3 FIGURE 8. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE RECEIVER OUTPUT CURRENT (mA) 20 0.5 RECEIVER OUTPUT VOLTAGE (V) FIGURE 7. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE RECEIVER OUTPUT CURRENT (mA) VOL, +85°C VOH, +25°C RECEIVER OUTPUT VOLTAGE (V) 0 7 7.5 30 VCC = VL = 5V 50 6 5 FIGURE 6. VL SUPPLY CURRENT vs ENABLE PIN VOLTAGE RECEIVER OUTPUT CURRENT (mA) RECEIVER OUTPUT CURRENT (mA) 60 4 RE VOLTAGE (V) VCC = 5V OR 3.3V, VL = 1.8V 8 VOL, +25°C VOL, +85°C 7 VOL, +125°C 6 5 4 VOH, +25°C VOH, +85°C 3 VOH, +125°C 2 1 0 0 0.5 1.0 1.5 1.8 RECEIVER OUTPUT VOLTAGE (V) FIGURE 10. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE FN7595.2 June 17, 2016 ISL3282EMRTEP Typical Performance Curves CL = 15pF, TA = +25°C; unless otherwise specified. (Continued) 45 VCC = 5V or 3.3V, VL = 1.5V 4.5 VOL, +85°C 4.0 VOL, +25°C PROPAGATION DELAY (ns) RECEIVER OUTPUT CURRENT (mA) 5.0 VOL, +125°C 3.5 3.0 2.5 2.0 VOH, +85°C VOH, +25°C 1.5 VOH, +125°C 1.0 40 35 VCC = 5.5V, TPLH 30 VCC = 5.5V, TPHL 25 0.5 0 0 0.2 0.4 0.6 0.8 1.0 1.2 20 1.4 1.5 -55 -35 -15 RECEIVER OUTPUT VOLTAGE (V) FIGURE 11. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE PROPAGATION DELAY (ns) 1.0 0.5 125 45 40 VCC = 3.3V, TPLH 35 VCC = 3.3V, TPHL 30 25 -55 -35 -15 5 25 45 65 TEMPERATURE (°C) 85 105 RECEIVER INPUT (V) 3.50 3.00 VCC = 5.0V, SKEW 2.50 2.00 1.50 1.00 0.50 -35 -15 5 25 45 65 TEMPERATURE (°C) 85 105 FIGURE 15. RECEIVER SKEW vs TEMPERATURE Submit Document Feedback 7 -55 -35 -15 5 25 45 65 TEMPERATURE (°C) 85 105 125 FIGURE 14. RECEIVER PROPAGATION DELAY vs TEMPERATURE 4.00 -55 20 125 125 RECEIVER OUTPUT (V) PROPAGATION DELAY (ns) VCC = 3.3V, SKEW 1.5 FIGURE 13. RECEIVER SKEW vs TEMPERATURE PROPAGATION DELAY (ns) 105 50 2.0 0.00 85 FIGURE 12. RECEIVER PROPAGATION DELAY vs TEMPERATURE 2.5 0.0 5 25 45 65 TEMPERATURE (°C) VCC = 5V 2.0 0 -2.0 5.0 A-B VL = 5V 4.0 3.0 VL = 2.5V 2.0 1.0 0 VL = 1.5V TIME (20ns/DIV) FIGURE 16. RECEIVER WAVEFORMS FN7595.2 June 17, 2016 ISL3282EMRTEP RECEIVER OUTPUT (V) RECEIVER INPUT (V) Typical Performance Curves CL = 15pF, TA = +25°C; unless otherwise specified. (Continued) Die Characteristics VCC = 3.3V 2.0 0 A-B -2.0 SUBSTRATE AND TDFN THERMAL PAD POTENTIAL (POWERED UP): GND TRANSISTOR COUNT: 4.0 140 VL = 3.3V 3.0 PROCESS: VL = 2.5V 2.0 VL = 1.5V 1.0 Si Gate BiCMOS 0 TIME (20ns/DIV) FIGURE 17. RECEIVER WAVEFORMS Revision History The revision history provided is for informational purposes only and is believed to be accurate, however, not warranted. Please go to web to make sure you have the latest Rev. DATE REVISION CHANGE June 17, 2016 FN7595.2 Updated title to fit 100 character limit. Removed Pb-Free bullet under Features section. Updated Ordering Information table by removing Pb-Free notes and obsolete parts. Added Tape and Reel Quantity and PKG DWG columns. Replaced Products section with About Intersil. Added the applicable POD. January 27, 2011 FN7595.1 In Figure 5 on page 6, corrected units of y axis from mA to µA. February 26, 2010 FN7595.0 Initial Release. 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For information regarding Intersil Corporation and its products, see www.intersil.com Submit Document Feedback 8 FN7595.2 June 17, 2016 ISL3282EMRTEP Package Outline Drawing L8.2x3A 8 LEAD THIN DUAL FLAT NO-LEAD PLASTIC PACKAGE WITH E-PAD Rev 2, 05/15 0.25 0.50 2.20 6 PIN 1 INDEX AREA (4X) 6 PIN #1 INDEX AREA B 3.00 A 1.80 +0.1/ -0.15 2.00 0.15 (8x0.40) 1.65 +0.1/ -0.15 TOP VIEW BOTTOM VIEW (8x0.25) PACKAGE OUTLINE (6x0.50) 0.75 SEE DETAIL "X" SIDE VIEW 1.80 3.00 0.05 (8x0.40) 1.65 C 0.20 REF C BASE PLANE SEATING PLANE 0.08 C 5 (8x0.20) 0.05 2.00 TYPICAL RECOMMENDED LAND PATTERN DETAIL "X" NOTES: 1. Dimensions are in millimeters. Dimensions in ( ) for Reference Only. 2. Dimensioning and tolerancing conform to ASME Y14.5m-1994. 3. Unless otherwise specified, tolerance : Decimal ± 0.05 4. Dimension b applies to the metallized terminal and is measured between 0.20mm and 0.32mm from the terminal tip. 5. Tiebar shown (if present) is a non-functional feature and may be located on any of the 4 sides (or ends). 6. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 indentifier may be either a mold or mark feature. Submit Document Feedback 9 FN7595.2 June 17, 2016