Signal and Power Isolated CAN Transceiver with Integrated Isolated DC-to-DC Converter ADM3053 FEATURES GENERAL DESCRIPTION 2.5 kV rms signal and power isolated CAN transceiver isoPower integrated isolated dc-to-dc converter 5 V operation on VCC 5 V or 3.3 V operation on VIO Complies with ISO 11898 standard High speed data rates of up to 1 Mbps Unpowered nodes do not disturb the bus Connect 110 or more nodes on the bus Slope control for reduced EMI Thermal shutdown protection High common-mode transient immunity: >25 kV/µs Safety and regulatory approvals (pending) UL recognition 2500 V rms for 1 minute per UL 1577 VDE Certificate of Conformity DIN EN 60747-5-2 (VDE 0884 Rev.2): 2003-01 Industrial operating temperature range (−40°C to +85°C) Available in wide-body, 20-lead SOIC package The ADM3053 is an isolated controller area network (CAN) physical layer transceiver with an integrated isolated dc-to-dc converter. The ADM3053 complies with the ISO 11898 standard. The device employs Analog Devices, Inc., iCoupler® technology to combine a 2-channel isolator, a CAN transceiver, and Analog Devices isoPower® dc-to-dc converter into a single SOIC surface mount package. An on-chip oscillator outputs a pair of square waveforms that drive an internal transformer to provide isolated power. The device is powered by a single 5 V supply realizing a fully isolated CAN solution. The ADM3053 creates a fully isolated interface between the CAN protocol controller and the physical layer bus. It is capable of running at data rates of up to 1 Mbps. The device has current limiting and thermal shutdown features to protect against output short circuits. The part is fully specified over the industrial temperature range and is available in a 20-lead, wide-body SOIC package. The ADM3053 contains isoPower technology that uses high frequency switching elements to transfer power through the transformer. Special care must be taken during printed circuit board (PCB) layout to meet emissions standards. Refer to the AN-0971 Application Note, Control of Radiated Emissions with isoPower Devices, for details on board layout considerations. APPLICATIONS CAN data buses Industrial field networks FUNCTIONAL BLOCK DIAGRAM VISOOUT VCC isoPower DC-TO-DC CONVERTER OSCILLATOR RECTIFIER REGULATOR VIO VISOIN VCC DIGITAL ISOLATION iCoupler PROTECTION TxD ENCODE TxD RS DECODE RS DECODE RxD ENCODE DRIVER SLOPE/ STANDBY RxD CANH CANL VREF RECEIVER REFERENCE VOLTAGE CAN TRANSCEIVER ADM3053 GND2 ISOLATION BARRIER LOGIC SIDE BUS SIDE 09293-001 GND1 VREF GND2 Figure 1. Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2011 Analog Devices, Inc. All rights reserved. ADM3053 TABLE OF CONTENTS Features .............................................................................................. 1 Test Circuits ..................................................................................... 12 Applications ....................................................................................... 1 Circuit Description......................................................................... 13 General Description ......................................................................... 1 CAN Transceiver Operation ..................................................... 13 Functional Block Diagram .............................................................. 1 Signal Isolation ........................................................................... 13 Revision History ............................................................................... 2 Power Isolation ........................................................................... 13 Specifications..................................................................................... 3 Truth Tables................................................................................. 13 Timing Specifications .................................................................. 4 Thermal Shutdown .................................................................... 13 Switching Characteristics ............................................................ 4 DC Correctness and Magnetic Field Immunity........................... 13 Regulatory Information ............................................................... 5 Applications Information .............................................................. 15 Insulation and Safety-Related Specifications ............................ 5 PCB Layout ................................................................................. 15 VDE 0884 Insulation Characteristics (Pending) ...................... 6 EMI Considerations ................................................................... 15 Absolute Maximum Ratings............................................................ 7 Insulation Lifetime ..................................................................... 15 ESD Caution .................................................................................. 7 Typical Applications ....................................................................... 17 Pin Configuration and Function Descriptions ............................. 8 Outline Dimensions ....................................................................... 18 Typical Performance Characteristics ............................................. 9 Ordering Guide .......................................................................... 18 REVISION HISTORY 5/11—Revision 0: Initial Version Rev. 0 | Page 2 of 20 ADM3053 SPECIFICATIONS All voltages are relative to their respective ground; 4.5 V ≤ VCC ≤ 5.5 V; 3.0 V ≤ VIO ≤ 5.5 V. All minimum/maximum specifications apply over the entire recommended operation range, unless otherwise noted. All typical specifications are at TA = 25°C, VCC = 5 V, VIO = 5 V unless otherwise noted. Table 1. Parameter SUPPLY CURRENT Logic Side isoPower Current Recessive State Dominant State TxD/RxD Data Rate 1 Mbps Logic Side iCoupler Current TxD/RxD Data Rate 1 Mbps DRIVER Logic Inputs Input Voltage High Input Voltage Low CMOS Logic Input Currents Differential Outputs Recessive Bus Voltage CANH Output Voltage CANL Output Voltage Differential Output Voltage Short-Circuit Current, CANH Symbol Min Typ Max Unit Test Conditions ICC ICC ICC 29 195 139 36 232 170 mA mA mA RL = 60 Ω, RS = low, see Figure 25 RL = 60 Ω, RS = low, see Figure 25 RL = 60 Ω, RS = low, see Figure 25 IIO 1.6 2.5 mA 0.25 VIO 500 V V µA Output recessive Output dominant TxD 200 V V V V mV mA mA mA TxD = high, RL = ∞, see Figure 22 TxD = low, see Figure 22 TxD = low, see Figure 22 TxD = low, RL = 45 Ω, see Figure 22 TxD = high, RL = ∞, see Figure 22 VCANH = −5 V VCANH = −36 V VCANL = 36 V −7 V < VCANL, VCANH < +12 V, see Figure 23, CL = 15 pF −7 V < VCANL, VCANH < +12 V, see Figure 23, CL = 15 pF See Figure 3 VIH VIL IIH, IIL 0.7 VIO VCANL, VCANH VCANH VCANL VOD VOD ISCCANH 2.0 2.75 0.5 1.5 −500 3.0 4.5 2.0 3.0 +50 −200 −100 Short-Circuit Current, CANL RECEIVER Differential Inputs Differential Input Voltage Recessive ISCCANL VIDR −1.0 +0.5 V Differential Input Voltage Dominant VIDD 0.9 5.0 V Input Voltage Hysteresis CANH, CANL Input Resistance Differential Input Resistance Logic Outputs Output Low Voltage Output High Voltage Short Circuit Current VOLTAGE REFERENCE Reference Output Voltage COMMON-MODE TRANSIENT IMMUNITY 1 SLOPE CONTROL Current for Slope Control Mode Slope Control Mode Voltage VHYS RIN RDIFF 5 20 25 100 mV kΩ kΩ VOL VOH IOS VIO − 0.3 7 1 150 0.2 VIO − 0.2 0.4 85 V V mA IOUT = 1.5 mA IOUT = −1.5 mA VOUT = GND1 or VIO |IREF = 50 µA| VCM = 1 kV, transient magnitude = 800 V VREF 2.025 25 3.025 V kV/µs ISLOPE VSLOPE −10 1.8 −200 3.3 µA V CM is the maximum common-mode voltage slew rate that can be sustained while maintaining specification-compliant operation. VCM is the common-mode potential difference between the logic and bus sides. The transient magnitude is the range over which the common mode is slewed. The common-mode voltage slew rates apply to both rising and falling common-mode voltage edges. Rev. 0 | Page 3 of 20 ADM3053 TIMING SPECIFICATIONS All voltages are relative to their respective ground; 3.0 V ≤ VIO ≤ 5.5 V; 4.5 V ≤ VCC ≤ 5.5 V. TA = −40°C to +85°C, unless otherwise noted. Table 2. Parameter DRIVER Maximum Data Rate Propagation Delay from TxD On to Bus Active Symbol Max Unit tonTxD 90 Mbps ns Propagation Delay from TxD Off to Bus Inactive toffTxD 120 ns RECEIVER Propagation Delay from TxD On to Receiver Active tonRxD 200 630 250 480 ns ns ns ns V/µs Typ 1 Propagation Delay from TxD Off to Receiver Inactive1 CANH, CANL SLEW RATE 1 Min toffRxD |SR| 7 Test Conditions RS = 0 Ω; see Figure 2 and Figure 24 RL = 60 Ω, CL = 100 pF RS = 0 Ω; see Figure 2 and Figure 24 RL = 60 Ω, CL = 100 pF RS = 0 Ω; see Figure 2 RS = 47 kΩ; see Figure 2 RS = 0 Ω; see Figure 2 RS = 47 kΩ; see Figure 2 RS = 47 kΩ Guaranteed by design and characterization. SWITCHING CHARACTERISTICS VIO 0.7VIO VTxD 0.25VIO 0V VOD VDIFF = VCANH – VCANL VDIFF 0.9V 0.5V VOR toffTxD tonTxD VIO VIO – 0.3V VRxD 0V tonRxD toffRxD Figure 2. Driver Propagation Delay, Rise/Fall Timing Rev. 0 | Page 4 of 20 09293-002 0.4V ADM3053 VRxD HIGH LOW 0.9 0.5 VID (V) 09293-004 VHYS Figure 3. Receiver Input Hysteresis REGULATORY INFORMATION Table 3. Pending ADM3053 Approvals Organization UL VDE Approval Type To be recognized under the Component Recognition Program of Underwriters Laboratories, Inc. To be certified according to DIN EN 60747-5-2 (VDE 0884 Rev. 2): 2003-01 Notes In accordance with UL 1577, each ADM3053 is proof tested by applying an insulation test voltage ≥2500 V rms for 1 second. In accordance with VDE 0884-2. INSULATION AND SAFETY-RELATED SPECIFICATIONS Table 4. Parameter Rated Dielectric Insulation Voltage Minimum External Air Gap (Clearance) Minimum External Tracking (Creepage) Minimum Internal Gap (Internal Clearance) Tracking Resistance (Comparative Tracking Index) Isolation Group Symbol L(I01) Value 2500 7.7 Unit V rms mm L(I02) 7.6 mm 0.017 min mm Conditions 1-minute duration Measured from input terminals to output terminals, shortest distance through air Measured from input terminals to output terminals, shortest distance along body Insulation distance through insulation >175 V DIN IEC 112/VDE 0303-1 CTI IIIa Material group (DIN VDE 0110: 1989-01, Table 1) Rev. 0 | Page 5 of 20 ADM3053 VDE 0884 INSULATION CHARACTERISTICS (PENDING) This isolator is suitable for basic electrical isolation only within the safety limit data. Maintenance of the safety data must be ensured by means of protective circuits. Table 5. Description CLASSIFICATIONS Installation Classification per DIN VDE 0110 for Rated Mains Voltage ≤150 V rms ≤300 V rms ≤400 V rms Climatic Classification Pollution Degree VOLTAGE Maximum Working Insulation Voltage Input-to-Output Test Voltage Method b1 Highest Allowable Overvoltage SAFETY-LIMITING VALUES Case Temperature Input Current Output Current Insulation Resistance at TS Conditions Symbol VIORM VPR VIO = 500 V Rev. 0 | Page 6 of 20 Unit I to IV I to III I to II 40/85/21 2 DIN VDE 0110, see Table 3 VIORM × 1.875 = VPR, 100% production tested, tm = 1 sec, partial discharge < 5 pC (Transient overvoltage, tTR = 10 sec) Maximum value allowed in the event of a failure Characteristic 424 VPEAK 795 VPEAK VTR 4000 VPEAK TS IS, INPUT IS, OUTPUT RS 150 265 335 >109 °C mA mA Ω ADM3053 ABSOLUTE MAXIMUM RATINGS TA = 25°C, unless otherwise noted. All voltages are relative to their respective ground. Table 6. Parameter VCC VIO Digital Input Voltage, TxD Digital Output Voltage, RxD CANH, CANL VREF RS Operating Temperature Range Storage Temperature Range ESD (Human Body Model) Lead Temperature Soldering (10 sec) Vapor Phase (60 sec) Infrared (15 sec) θJA Thermal Impedance TJ Junction Temperature Rating −0.5 V to +6 V −0.5 V to +6 V −0.5 V to VIO + 0.5 V −0.5 V to VIO + 0.5 V −36 V to +36 V −0.5 V to +6 V −0.5 V to +6 V −40°C to +85°C −55°C to +150°C 3 kV 300°C 215°C 220°C 53°C/W 130°C Table 7. Maximum Continuous Working Voltage1 Parameter AC Voltage Bipolar Waveform Max Unit Reference Standard 424 V peak 50 year minimum lifetime Unipolar Waveform Basic Insulation 560 V peak Maximum approved working voltage per VDE 0884 Part 2 DC Voltage Basic Insulation 560 V peak Maximum approved working voltage per VDE 0884 Part 2 1 Refers to continuous voltage magnitude imposed across the isolation barrier. See the Insulation Lifetime section for more details. ESD CAUTION Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Rev. 0 | Page 7 of 20 ADM3053 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS GND1 1 20 GND2 NC 2 19 VISOIN GND1 3 18 RS RxD 4 ADM3053 TxD 5 TOP VIEW (Not to Scale) VIO 6 GND1 7 17 CANH 16 GND2 15 CANL 14 VREF VCC 8 GND1 9 12 VISOOUT GND1 10 11 GND2 NOTES 1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN. 2. PIN 12 AND PIN 19 MUST BE CONNECTED EXTERNALLY. 09293-005 13 GND2 Figure 4. Pin Configuration Table 8. Pin Function Descriptions Pin No. 1 2 3 4 5 6 Mnemonic GND1 NC GND1 RxD TxD VIO 7 8 GND1 VCC 9 10 11 12 GND1 GND1 GND2 VISOOUT 13 14 15 16 17 18 19 GND2 VREF CANL GND2 CANH RS VISOIN 20 GND2 Description Ground, Logic Side. No Connect. Do not connect to this pin. Ground, Logic Side. Receiver Output Data. Driver Input Data. iCoupler Power Supply. It is recommended that a 0.1 μF and a 0.01 μF decoupling capacitor be fitted between Pin 6 and GND1. See Figure 28 for layout recommendations. Ground, Logic Side. isoPower Power Supply. It is recommended that a 0.1 μF and a 10 μF decoupling capacitor be fitted between Pin 8 and Pin 9. Ground, Logic Side. Ground, Logic Side. Ground, Bus Side. Isolated Power Supply Output. This pin must be connected externally to VISOIN. It is recommended that a reservoir capacitor of 10 μF and a decoupling capacitor of 0.1 μF be fitted between Pin 12 and Pin 11. Ground (Bus Side). Reference Voltage Output. Low-Level CAN Voltage Input/Output. Ground (Bus Side). High-Level CAN Voltage Input/Output. Slope Resistor Input. Isolated Power Supply Input. This pin must be connected externally to VISOOUT. It is recommended that a 0.1 μF and a 0.01 μF decoupling capacitor be fitted between Pin 19 and Pin 20. Ground (Bus Side). Rev. 0 | Page 8 of 20 ADM3053 TYPICAL PERFORMANCE CHARACTERISTICS 160 180 RECEIVER INPUT HYSTERESIS (mV) VCC = 5.5V, VIO = 5V VCC = 5V, VIO = 5V 80 60 40 0 100 1000 DATA RATE (kbps) 165 160 VCC = 5V, VIO = 5V 155 VCC = 5V, VIO = 3.3V 150 –40 09293-100 20 170 PROPAGATION DELAY TxD ON TO BUS ACTIVE, tonTxD (ns) 45 SLEW RATE (V/µs) 40 35 30 25 20 15 10 0 30 40 50 60 70 80 RESISTANCE, RS (Ω) 09293-101 5 20 Figure 6. Driver Slew Rate vs. Resistance, RS 60 85 53 52 51 VCC = 5V, VIO = 3.3V 50 49 VCC = 5V, VIO = 5V 48 47 –40 –15 10 35 60 85 TEMPERATURE (°C) Figure 9. Propagation Delay from TxD On to Bus Active vs. Temperature 5.5 PROPAGATION DELAY TxD OFF TO BUS INACTIVE, toffTxD (ns) 96 4.5 3.5 2.5 VIO = 5V 1.5 VIO = 3.3V 0.5 100 1000 DATA RATE (kbps) Figure 7. Supply Current, IIO vs. Data Rate 94 92 VCC = 5V, VIO = 3.3V 90 88 86 VCC = 5V, VIO = 5V 84 82 80 78 –40 09293-102 SUPPLY CURRENT, IIO (mA) 35 Figure 8. Receiver Input Hysteresis vs. Temperature 50 10 10 TEMPERATURE (°C) Figure 5. Supply Current, ICC vs. Data Rate 0 –15 09293-104 100 175 –15 10 35 TEMPERATURE (°C) 60 85 09293-105 SUPPLY CURRENT, ICC (mA) VCC = 4.5V, VIO = 5V 120 09293-103 140 Figure 10. Propagation Delay from TxD Off to Bus Inactive vs. Temperature Rev. 0 | Page 9 of 20 ADM3053 VCC = 5V, VIO = 3.3V, RS = 0Ω 146 144 142 140 VCC = 5V, VIO = 5V, RS = 0Ω 138 136 –15 10 35 60 85 TEMPERATURE (°C) VCC = 5V, VIO = 5V, RS = 47kΩ 400 300 200 100 0 –40 –15 10 35 60 85 TEMPERATURE (°C) DIFFERENTIAL OUTPUT VOLTAGE DOMINANT, VOD (V) 200 VCC = 5V, VIO = 5V, RS = 0Ω 150 100 50 35 60 290 285 280 VCC = 5V, VIO = 5V, RS = 47kΩ –15 10 35 60 85 2.55 2.50 2.45 VCC VCC VCC VCC 2.40 = 5V, = 5V, = 5V, = 5V, VIO = 5V, RL = 60Ω VIO = 3.3V, RL = 60Ω VIO = 5V, RL = 45Ω VIO = 3.3V, RL = 45Ω 2.35 2.30 –15 10 35 60 85 TEMPERATURE (°C) 85 TEMPERATURE (°C) Figure 13. Propagation Delay from TxD Off to Receiver Inactive vs. Temperature 2.55 VIO = 5V, TA = 25°C, RL = 60Ω 2.50 2.45 2.40 2.35 VIO = 5V, TA = 25°C, RL = 45Ω 2.30 2.25 4.5 09293-108 PROPAGATION DELAY TxD OFF TO RECEIVER INACTIVE, toffRxD (ns) VCC = 5V, VIO = 3.3V, RS = 0Ω 10 295 Figure 15. Differential Output Voltage Dominant vs. Temperature 250 –15 VCC = 5V, VIO = 3.3V, RS = 47kΩ 300 2.25 –40 Figure 12. Propagation Delay from TxD On to Receiver Active vs. Temperature 0 –40 305 Figure 14. Propagation Delay from TxD Off to Receiver Inactive vs. Temperature DIFFERENTIAL OUTPUT VOLTAGE DOMINANT, VOD (V) 500 310 TEMPERATURE (°C) 09293-107 PROPAGATION DELAY TxD ON TO RECEIVER ACTIVE, tonRxD (ns) VCC = 5V, VIO = 3.3V, RS = 47kΩ 315 275 –40 Figure 11. Propagation Delay from TxD Off to Bus Inactive vs. Temperature 600 320 4.7 4.9 5.1 5.3 5.5 SUPPLY VOLTAGE, VCC (V) Figure 16. Differential Output Voltage Dominant vs. Supply Voltage, VCC Rev. 0 | Page 10 of 20 09293-111 134 –40 325 09293-110 148 330 09293-109 PROPAGATION DELAY TxD OFF TO RECEIVER INACTIVE, toffRxD (ns) 150 09293-106 PROPAGATION DELAY TxD OFF TO BUS INACTIVE, toffTxD (ns) 152 ADM3053 2.80 VCC = 5V, VIO = 5V, IREF = +50µA 2.70 VCC = 5V, VIO =5V, IREF = +5µA 2.65 VCC = 5V, VIO = 5V, IREF = –5µA 2.60 VCC = 5V, VIO = 5V, IREF = –50µA 2.55 2.50 2.40 –40 –15 10 35 60 85 TEMPERATURE (°C) 4.885 VCC = 5V, VIO = 5V, IOUT = –1.5mA 4.880 4.875 4.870 4.865 4.860 4.855 –40 09293-112 2.45 4.890 RECEIVER OUTPUT LOW VOLTAGE, VOL (mV) SUPPLY CURRENT, ICC (mA) 120 100 80 60 40 10 35 60 85 TEMPERATURE (°C) 09293-113 20 Figure 18. Supply Current ICC vs. Temperature 140 134 132 130 128 126 124 122 120 4.8 4.9 5.0 5.1 5.2 5.3 SUPPLY VOLTAGE, VCC (V) 5.4 5.5 09293-114 SUPPLY CURRENT, ICC (mA) 136 4.7 85 100 80 60 40 20 0 –40 –15 10 35 60 TEMPERATURE (°C) Figure 21. Receiver Output Low Voltage vs. Temperature VIO = 5V TA = 25°C DATA RATE = 1Mbps 138 4.6 60 120 VCC = 5V VIO = 5V 140 DATA RATE = 1Mbps RL = 60Ω 118 4.5 35 Figure 20. Receiver Output High Voltage vs. Temperature 160 –15 10 TEMPERATURE (°C) Figure 17. Reference Voltage vs. Temperature 0 –40 –15 Figure 19. Supply Current, ICC vs. Supply Voltage VCC Rev. 0 | Page 11 of 20 85 09293-116 REFERENCE VOLTAGE, VREF (V) 2.75 09293-115 RECEIVER OUTPUT HIGH VOLTAGE, VOH (V) 4.895 ADM3053 TEST CIRCUITS CANH RL 2 VOD TxD RL VCANH RL 2 CL VOC CANL RxD 09293-006 VCANH 09293-008 TxD 15pF Figure 22. Driver Voltage Measurement Figure 24. Switching Characteristics Measurements VID RxD CL CANL 09293-007 CANH Figure 23. Receiver Voltage Measurements 100nF 10µF 100nF 10µF VCC VISOOUT isoPower DC-TO-DC CONVERTER OSCILLATOR RECTIFIER REGULATOR VIO 10µF 10µF 100nF VCC DIGITAL ISOLATION iCoupler PROTECTION TxD ENCODE TxD RS DECODE RxD CANH RL CANL RECEIVER REFERENCE VOLTAGE CAN TRANSCEIVER ADM3053 LOGIC SIDE RS DRIVER SLOPE/ STANDBY RxD ENCODE VREF GND1 RS DECODE VREF GND2 ISOLATION BARRIER GND2 BUS SIDE Figure 25. Supply Current Measurement Test Circuit Rev. 0 | Page 12 of 20 09293-009 100nF VISOIN ADM3053 CIRCUIT DESCRIPTION CAN TRANSCEIVER OPERATION TRUTH TABLES A CAN bus has two states called dominant and recessive. A dominant state is present on the bus when the differential voltage between CANH and CANL is greater than 0.9 V. A recessive state is present on the bus when the differential voltage between CANH and CANL is less than 0.5 V. During a dominant bus state, the CANH pin is high, and the CANL pin is low. During a recessive bus state, both the CANH and CANL pins are in the high impedance state. The truth tables in this section use the abbreviations found in Table 9. Pin 18 (RS) allows two different modes of operation to be selected: high-speed and slope control. For high-speed operation, the transmitter output transistors are simply switched on and off as fast as possible. In this mode, no measures are taken to limit the rise and fall slopes. A shielded cable is recommended to avoid EMI problems. High-speed mode is selected by connecting Pin 18 to ground. Slope control mode allows the use of an unshielded twisted pair or a parallel pair of wires as bus lines. To reduce EMI, the rise and fall slopes should be limited. The rise and fall slopes can be programmed with a resistor connected from Pin 18 to ground. The slope is proportional to the current output at Pin 18. SIGNAL ISOLATION The ADM3053 signal isolation is implemented on the logic side of the interface. The part achieves signal isolation by having a digital isolation section and a transceiver section (see Figure 1). Data applied to the TxD pin referenced to logic ground (GND1) are coupled across an isolation barrier to appear at the transceiver section referenced to isolated ground (GND2). Similarly, the single-ended receiver output signal, referenced to isolated ground in the transceiver section, is coupled across the isolation barrier to appear at the RxD pin referenced to logic ground (GND1). The signal isolation is powered by the VIO pin and allows the digital interface to 3.3 V or 5 V logic. POWER ISOLATION The ADM3053 power isolation is implemented using an isoPower integrated isolated dc-to-dc converter. The dc-to-dc converter section of the ADM3053 works on principles that are common to most modern power supplies. It is a secondary side controller architecture with isolated pulse-width modulation (PWM) feedback. VCC power is supplied to an oscillating circuit that switches current into a chip-scale air core transformer. Power transferred to the secondary side is rectified and regulated to 5 V. The secondary (VISO) side controller regulates the output by creating a PWM control signal that is sent to the primary (VCC) side by a dedicated iCoupler data channel. The PWM modulates the oscillator circuit to control the power being sent to the secondary side. Feedback allows for significantly higher power and efficiency. Table 9. Truth Table Abbreviations Letter H L X Z I NC Description High level Low level Don’t care High impedance (off ) Indeterminate Not connected Table 10. Transmitting Supply Status VIO VCC On On On On On On Off On On Off Input TxD L H Floating X L Outputs Bus State CANH Dominant H Recessive Z Recessive Z Recessive Z Indeterminate I CANL L Z Z Z I Table 11. Receiving Supply Status VIO VCC On On On On On On On On Off On On Off Inputs VID = CANH − CANL ≥ 0.9 V ≤ 0.5 V 0.5 V < VID < 0.9 V Inputs open X1 X1 Bus State Dominant Recessive X1 Recessive X1 X1 Output RxD L H I H I H X = don’t care. 1 THERMAL SHUTDOWN The ADM3053 contains thermal shutdown circuitry that protects the part from excessive power dissipation during fault conditions. Shorting the driver outputs to a low impedance source can result in high driver currents. The thermal sensing circuitry detects the increase in die temperature under this condition and disables the driver outputs. This circuitry is designed to disable the driver outputs when a die temperature of 150°C is reached. As the device cools, the drivers are reenabled at a temperature of 140°C. DC CORRECTNESS AND MAGNETIC FIELD IMMUNITY The digital signals transmit across the isolation barrier using iCoupler technology. This technique uses chip-scale transformer windings to couple the digital signals magnetically from one side of the barrier to the other. Digital inputs are encoded into waveforms that are capable of exciting the primary transformer Rev. 0 | Page 13 of 20 ADM3053 winding. At the secondary winding, the induced waveforms are decoded into the binary value that was originally transmitted. Positive and negative logic transitions at the isolator input cause narrow (~1 ns) pulses to be sent to the decoder via the transformer. The decoder is bistable and is, therefore, either set or reset by the pulses, indicating input logic transitions. In the absence of logic transitions at the input for more than 1 µs, periodic sets of refresh pulses indicative of the correct input state are sent to ensure dc correctness at the output. If the decoder receives no internal pulses of more than approximately 5 μs, the input side is assumed to be unpowered or nonfunctional, in which case, the isolator output is forced to a default state by the watchdog timer circuit. This situation should occur in the ADM3053 devices only during power-up and power-down operations. The limitation on the ADM3053 magnetic field immunity is set by the condition in which induced voltage in the transformer receiving coil is sufficiently large to either falsely set or reset the decoder. The following analysis defines the conditions under which this can occur. The preceding magnetic flux density values correspond to specific current magnitudes at given distances from the ADM3053 transformers. Figure 27 expresses these allowable current magnitudes as a function of frequency for selected distances. As shown in Figure 27, the ADM3053 is extremely immune and can be affected only by extremely large currents operated at high frequency very close to the component. For the 1 MHz example, a 0.5 kA current must be placed 5 mm away from the ADM3053 to affect component operation. V = (−dβ/dt)Σπrn2; n = 1, 2, … , N where: β is magnetic flux density (gauss). N is the number of turns in the receiving coil. rn is the radius of the nth turn in the receiving coil (cm). DISTANCE = 1m 100 10 DISTANCE = 100mm 1 DISTANCE = 5mm 0.1 0.01 1k 1M 10M 100M Figure 27. Maximum Allowable Current for Various Current-to-ADM3053 Spacings Note that in combinations of strong magnetic field and high frequency, any loops formed by the printed circuit board (PCB) traces can induce error voltages sufficiently large to trigger the thresholds of succeeding circuitry. Proceed with caution in the layout of such traces to prevent this from occurring. 100 10 1 0.1 100M 09293-010 0.01 1M 10k 100k 10M MAGNETIC FIELD FREQUENCY (Hz) 100k MAGNETIC FIELD FREQUENCY (Hz) Given the geometry of the receiving coil in the ADM3053 and an imposed requirement that the induced voltage be, at most, 50% of the 0.5 V margin at the decoder, a maximum allowable magnetic field is calculated as shown in Figure 26. 0.001 1k 10k 09293-011 MAXIMUM ALLOWABLE CURRENT (kA) 1k The 3.3 V operating condition of the ADM3053 is examined because it represents the most susceptible mode of operation. The pulses at the transformer output have an amplitude of >1.0 V. The decoder has a sensing threshold of about 0.5 V, thus establishing a 0.5 V margin in which induced voltages can be tolerated. The voltage induced across the receiving coil is given by MAXIMUM ALLOWABLE MAGNETIC FLUX DENSITY (kgauss) For example, at a magnetic field frequency of 1 MHz, the maximum allowable magnetic field of 0.2 kgauss induces a voltage of 0.25 V at the receiving coil. This is about 50% of the sensing threshold and does not cause a faulty output transition. Similarly, if such an event occurs during a transmitted pulse (and is of the worst-case polarity), it reduces the received pulse from >1.0 V to 0.75 V, which is still well above the 0.5 V sensing threshold of the decoder. Figure 26. Maximum Allowable External Magnetic Flux Density Rev. 0 | Page 14 of 20 ADM3053 APPLICATIONS INFORMATION PCB LAYOUT The ADM3053 signal and power isolated CAN transceiver contains an isoPower integrated dc-to-dc converter, requiring no external interface circuitry for the logic interfaces. Power supply bypassing is required at the input and output supply pins (see Figure 28). The power supply section of the ADM3053 uses a 180 MHz oscillator frequency to pass power efficiently through its chip-scale transformers. In addition, the normal operation of the data section of the iCoupler introduces switching transients on the power supply pins. Bypass capacitors are required for several operating frequencies. Noise suppression requires a low inductance, high frequency capacitor, whereas ripple suppression and proper regulation require a large value capacitor. These capacitors are connected between GND1 and Pin 6 (VIO) for VIO. It is recommended that a combination of 100 nF and 10 nF be placed as shown in Figure 28 (C6 and C4. It is recommended that a combination of two capacitors are placed between Pin 8 (VCC) and Pin 9 (GND1) for VCC as shown in Figure 28 (C2 and C1). The VISOIN and VISOOUT capacitors are connected between Pin 11 (GND2) and Pin 12 (VISOOUT) with recommended values of 100 nF and 10 μF as shown in Figure 28 (C5 and C8). Two capacitors are recommended to be fitted Pin 19 (VISOIN) and Pin 20 (GND2) with values of 100nF and 10nF as shown in Figure 28 (C9 and C7). The best practice recommended is to use a very low inductance ceramic capacitor, or its equivalent, for the smaller value. The total lead length between both ends of the capacitor and the input power supply pin should not exceed 10 mm. pins exceeding the absolute maximum ratings for the device, thereby leading to latch-up and/or permanent damage. The ADM3053 dissipates approximately 650 mW of power when fully loaded. Because it is not possible to apply a heat sink to an isolation device, the devices primarily depend on heat dissipation into the PCB through the GND pins. If the devices are used at high ambient temperatures, provide a thermal path from the GND pins to the PCB ground plane. The board layout in Figure 28 shows enlarged pads for Pin 1, Pin 3, Pin 9, Pin 10, Pin 11, Pin 14, Pin 16, and Pin 20. Implement multiple vias from the pad to the ground plane to reduce the temperature inside the chip significantly. The dimensions of the expanded pads are at the discretion of the designer and dependent on the available board space. EMI CONSIDERATIONS The dc-to-dc converter section of the ADM3053 must, of necessity, operate at very high frequency to allow efficient power transfer through the small transformers. This creates high frequency currents that can propagate in circuit board ground and power planes, causing edge and dipole radiation. Grounded enclosures are recommended for applications that use these devices. If grounded enclosures are not possible, good RF design practices should be followed in the layout of the PCB. See the AN-0971 Application Note, Control of Radiated Emissions with isoPower Devices, for more information. INSULATION LIFETIME All insulation structures eventually break down when subjected to voltage stress over a sufficiently long period. The rate of insulation degradation is dependent on the characteristics of the voltage waveform applied across the insulation. Analog Devices conducts an extensive set of evaluations to determine the lifetime of the insulation structure within the ADM3053. 09293-012 Accelerated life testing is performed using voltage levels higher than the rated continuous working voltage. Acceleration factors for several operating conditions are determined, allowing calculation of the time to failure at the working voltage of interest. The values shown in Table 5 summarize the peak voltages for 50 years of service life in several operating conditions. In many cases, the working voltage approved by agency testing is higher than the 50 year service life voltage. Operation at working voltages higher than the service life voltage listed leads to premature insulation failure. Figure 28. Recommended PCB Layout In applications involving high common-mode transients, ensure that board coupling across the isolation barrier is minimized. Furthermore, design the board layout such that any coupling that does occur equally affects all pins on a given component side. Failure to ensure this can cause voltage differentials between The insulation lifetime of the ADM3053 depends on the voltage waveform type imposed across the isolation barrier. The iCoupler insulation structure degrades at different rates, depending on whether the waveform is bipolar ac, unipolar ac, or dc. Figure 29, Figure 30, and Figure 31 illustrate these different isolation voltage waveforms. Rev. 0 | Page 15 of 20 ADM3053 Bipolar ac voltage is the most stringent environment. A 50 year operating lifetime under the bipolar ac condition determines the Analog Devices recommended maximum working voltage. 0V NOTES 1. THE VOLTAGE IS SHOWN AS SINUSODIAL FOR ILLUSTRATION PURPOSES ONLY. IT IS MEANT TO REPRESENT ANY VOLTAGE WAVEFORM VARYING BETWEEN 0 AND SOME LIMITING VALUE. THE LIMITING VALUE CAN BE POSITIVE OR NEGATIVE, BUT THE VOLTAGE CANNOT CROSS 0V. 09293-013 RATED PEAK VOLTAGE 0V Figure 29. Bipolar AC Waveform 09293-014 RATED PEAK VOLTAGE 0V Figure 30. DC Waveform Rev. 0 | Page 16 of 20 Figure 31. Unipolar AC Waveform 09293-015 In the case of unipolar ac or dc voltage, the stress on the insulation is significantly lower. This allows operation at higher working voltages while still achieving a 50 year service life. The working voltages listed in Table 5 can be applied while maintaining the 50 year minimum lifetime, provided the voltage conforms to either the unipolar ac or dc voltage cases. Any cross insulation voltage waveform that does not conform to Figure 30 or Figure 31 should be treated as a bipolar ac waveform, and its peak voltage should be limited to the 50-year lifetime voltage value listed in Table 5. RATED PEAK VOLTAGE ADM3053 TYPICAL APPLICATIONS Figure 32 is an example circuit diagram using the ADM3053. 5V SUPPLY 100nF 10µF 100nF 10µF VISOOUT VCC isoPowerDC-TO-DC CONVERTER OSCILLATOR RECTIFIER 3.3V/5V SUPPLY REGULATOR VIO 10nF VISOIN 100nF 100nF 10nF VCC DIGITAL ISOLATION iCoupler ENCODE DECODE ENCODE RT CANL RECEIVER REFERENCE VOLTAGE CAN TRANSCEIVER ADM3053 LOGIC SIDE CANH CANH RxD VREF GND1 RS DRIVER SLOPE/ STANDBY VREF CANL BUS CONNECTOR GND2 ISOLATION BARRIER GND2 BUS SIDE Figure 32. Example Circuit Diagram Using the ADM3053 Rev. 0 | Page 17 of 20 09293-016 RxD RS DECODE RS CAN CONTROLLER PROTECTION TxD TxD ADM3053 OUTLINE DIMENSIONS 13.00 (0.5118) 12.60 (0.4961) 11 20 7.60 (0.2992) 7.40 (0.2913) 10 2.65 (0.1043) 2.35 (0.0925) 0.30 (0.0118) 0.10 (0.0039) COPLANARITY 0.10 10.65 (0.4193) 10.00 (0.3937) 1.27 (0.0500) BSC 0.51 (0.0201) 0.31 (0.0122) SEATING PLANE 0.75 (0.0295) 45° 0.25 (0.0098) 8° 0° 0.33 (0.0130) 0.20 (0.0079) COMPLIANT TO JEDEC STANDARDS MS-013-AC CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 1.27 (0.0500) 0.40 (0.0157) 06-07-2006-A 1 Figure 33. 20-Lead Standard Small Outline Package [SOIC_W] Wide Body (RW-20) Dimensions shown in millimeters and (inches) ORDERING GUIDE Model1 ADM3053BRWZ ADM3053BRWZ-REEL7 EVAL-ADM3053EBZ 1 Temperature Range −40°C to +85°C −40°C to +85°C Package Description 20-Lead SOIC_W 20-Lead SOIC_W ADM3053 Evaluation Board Z = RoHS Compliant Part. Rev. 0 | Page 18 of 20 Package Option RW-20 RW-20 ADM3053 NOTES Rev. 0 | Page 19 of 20 ADM3053 NOTES ©2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D09293-0-5/11(0) Rev. 0 | Page 20 of 20