Product Folder Sample & Buy Support & Community Tools & Software Technical Documents Reference Design ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 ISO154x Low-Power Bidirectional I2C Isolators 1 Features • 1 • • • • • • • 3 Description 2 Isolated Bidirectional, I C Compatible, Communication Supports up to 1-MHz Operation 3-V to 5.5-V Supply Range Open-Drain Outputs With 3.5-mA Side 1 and 35mA Side 2 Sink Current Capability –40°C to +125°C Operating Temperature ±50-kV/µs Transient Immunity (Typical) HBM ESD Protection of 4 kV on All Pins; 8 kV on Bus Pins Safety-Related Certifications: – 4242-VPK Isolation per DIN V VDE V 0884-10 (VDE V 0884-10): 2006-12 – 2500-VRMS Isolation for 1 Minute per UL 1577 – CSA Component Acceptance Notice 5A, IEC 60950-1 and IEC 61010-1 End Equipment Standards – CQC Basic Insulation per GB4943.1-2011 2 Applications • • • • • • Isolated I2C Buses SMBus and PMBus Interfaces Open-Drain Networks Motor Control Systems Battery Management I2C Level Shifting The ISO1540 and ISO1541 devices are low-power, bidirectional isolators that are compatible with I2C interfaces. These devices have logic input and output buffers that are separated by Texas Instruments Capacitive Isolation technology using a silicon dioxide (SiO2) barrier. When used with isolated power supplies, these devices block high voltages, isolate grounds, and prevent noise currents from entering the local ground and interfering with or damaging sensitive circuitry. This isolation technology provides for function, performance, size, and power consumption advantages when compared to optocouplers. The ISO1540 and ISO1541 devices enable a complete isolated I2C interface to be implemented within a small form factor. The ISO1540 has two isolated bidirectional channels for clock and data lines while the ISO1541 has a bidirectional data and a unidirectional clock channel. The ISO1541 is useful in applications that have a single master while the ISO1540 is suitable for multimaster applications. For applications where clock stretching by the slave is possible, the ISO1540 device should be used. Isolated bidirectional communication is accomplished within these devices by offsetting the low-level output voltage on side 1 to a value greater than the highlevel input voltage on side 1, thus preventing an internal logic latch that otherwise would occur with standard digital isolators. Device Information(1) PART NUMBER ISO1540 ISO1541 PACKAGE SOIC (8) BODY SIZE (NOM) 4.90 mm × 3.91 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Simplified Schematic VCC2 Isolation Capacitor VCC1 SDA1 or SCL1 GND1 SDA2 or SCL2 GND2 VREF 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com Table of Contents 1 2 3 4 5 6 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 7 8 1 1 1 2 4 5 Absolute Maximum Ratings ...................................... 5 ESD Ratings.............................................................. 6 Recommended Operating Conditions....................... 6 Thermal Information .................................................. 6 Power Ratings........................................................... 6 Insulation Specifications............................................ 7 Safety-Related Certifications..................................... 8 Safety Limiting Values .............................................. 8 Electrical Characteristics........................................... 9 Supply Current Characteristics ............................. 10 Timing Requirements ............................................ 10 Switching Characteristics ...................................... 11 Insulation Characteristics Curves ......................... 12 Typical Characteristics .......................................... 13 Parameter Measurement Information ................ 16 Detailed Description ............................................ 18 8.1 8.2 8.3 8.4 8.5 9 Overview ................................................................. Functional Block Diagrams ..................................... Feature Description................................................. Isolator Functional Principle.................................... Device Functional Modes........................................ 18 18 19 19 20 Application and Implementation ........................ 21 9.1 Application Information............................................ 21 9.2 Typical Application .................................................. 23 10 Power Supply Recommendations ..................... 25 11 Layout................................................................... 25 11.1 Layout Guidelines ................................................. 25 11.2 Layout Example .................................................... 25 12 Device and Documentation Support ................. 26 12.1 12.2 12.3 12.4 12.5 12.6 12.7 Documentation Support ........................................ Related Links ........................................................ Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 26 26 26 26 26 26 26 13 Mechanical, Packaging, and Orderable Information ........................................................... 27 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision C (June 2015) to Revision D Page • Deleted the Device Comparison Table; see the Features List table for device comparison ................................................ 4 • Changed the status of CQC certification from planned to certified ....................................................................................... 8 • Changed the Regulatory Information table to Safety-Related Certifications and updated content........................................ 8 • Changed formatting of supply current parameters to combine device and sides. Moved parameters to separate table ... 10 • Added the Receiving Notification of Documentation Updates section ................................................................................ 26 Changes from Revision B (May 2013) to Revision C Page • Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1 • VDE Standard changed to DIN V VDE V 0884-10 (VDE V 0884-10): 2006-12 .................................................................... 1 • Changed minimum air gap (Clearance) parameter, L(I01), to external clearance, CLR, and minimum external tracking (creepage) parameter, L(I02), to external creepage................................................................................................. 7 • Changed values and test conditions in the Insulation Specifications table ............................................................................ 7 • Changed the descriptions of VDE and CSA information ....................................................................................................... 8 Changes from Revision A (October 2012) to Revision B Page • Change Safety Feature From: (VDE 0884 Part 2) (Pending) To: (VDE 0884 Part 2) (Approved)......................................... 1 • Changed, VDE column From: File number: 40016131 (pending) To: File number: 40016131.............................................. 8 2 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 Changes from Original (July 2012) to Revision A Page • Changed From: CSA Component Acceptance Notice 5A (Pending) To: CSA Component Acceptance Notice 5A (Approved) .............................................................................................................................................................................. 1 • Changed From: IEC 60950-1 and IEC 61010-1 End Equipment Standards (Pending) To: IEC 60950-1 and IEC 61010-1 End Equipment Standards (Approved)..................................................................................................................... 1 • Changed Safety-Related Certifications, CSA column From: File number: 220991 (pending) To: File number: 220991....... 8 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 3 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 5 Pin Configuration and Functions ISO1540 D Package 8-Pin SOIC Top View 1 8 VCC2 SDA1 2 7 SDA2 SCL1 3 6 SCL2 GND1 4 5 GND2 Isolation VCC1 Side 1 Side 2 Not to scale Pin Functions—ISO1540 PIN NAME NO. GND1 4 GND2 SCL1 I/O DESCRIPTION — Ground, side 1 5 — Ground, side 2 3 I/O Serial clock input / output, side 1 SCL2 6 I/O Serial clock input / output, side 2 SDA1 2 I/O Serial data input / output, side 1 SDA2 7 I/O Serial data input / output, side 2 VCC1 1 — Supply voltage, side 1 VCC2 8 — Supply voltage, side 2 4 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 ISO1541 D Package 8-Pin SOIC Top View 1 8 VCC2 SDA1 2 7 SDA2 SCL1 3 6 SCL2 GND1 4 5 GND2 Isolation VCC1 Side 1 Side 2 Not to scale Pin Functions—ISO1541 PIN I/O DESCRIPTION NAME NO. GND1 4 — Ground, side 1 GND2 5 — Ground, side 2 SCL1 3 I Serial clock input, side 1 SCL2 6 O Serial clock output, side 2 SDA1 2 I/O Serial data input / output, side 1 SDA2 7 I/O Serial data input / output, side 2 VCC1 1 — Supply voltage, side 1 VCC2 8 — Supply voltage, side 2 6 Specifications 6.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) (1) (2) Voltage MIN MAX VCC1, VCC2 –0.5 6 SDA1, SCL1 –0.5 VCC1 + 0.5 (3) SDA2, SCL2 –0.5 VCC2 + 0.5 (3) SDA1, SCL1 –20 20 SDA2, SCL2 –100 100 IO Output current TJ(MAX) Maximum junction temperature Tstg Storage temperature (1) (2) (3) –65 UNIT V mA 150 °C 150 °C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltage values here within are with respect to the local ground pin (GND1 or GND2) and are peak voltage values. Maximum voltage must not exceed 6 V. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 5 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 6.2 ESD Ratings VALUE Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) V(ESD) (1) (2) Electrostatic discharge Bus pins ±8000 All pins ±4000 Charged-device model (CDM), per JEDEC specification JESD22C101 (2) ±1500 Machine Model JEDEC JESD22-A115-A, all pins ±200 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 6.3 Recommended Operating Conditions MIN MAX VCC1, VCC2 Supply voltage 3 5.5 V VSDA1, VSCL1 Input and output signal voltages, side 1 0 VCC1 V VSDA2, VSCL2 Input and output signal voltages, side 2 0 VCC2 V VIL1 Low-level input voltage, side 1 0 0.5 V VIH1 High-level input voltage, side 1 0.7 × VCC1 VCC1 V VIL2 Low-level input voltage, side 2 0 0.3 × VCC2 V VIH2 High-level input voltage, side 2 0.7 × VCC2 VCC2 IOL1 Output current, side 1 0.5 3.5 mA IOL2 Output current, side 2 0.5 35 mA C1 Capacitive load, side 1 40 pF C2 Capacitive load, side 2 400 pF (1) UNIT V fMAX Operating frequency TA Ambient temperature –40 125 °C TJ Junction temperature –40 136 °C TSD Thermal shutdown 139 171 °C (1) 1 MHz This represents the maximum frequency with the maximum bus load (C) and the maximum current sink (IO). If the system has less bus capacitance, then higher frequencies can be achieved. 6.4 Thermal Information ISO154x THERMAL METRIC (1) D (SOIC) UNIT 8 PINS RθJA Junction-to-ambient thermal resistance 114.6 °C/W RθJC(top) Junction-to-case (top) thermal resistance 69.6 °C/W RθJB Junction-to-board thermal resistance 55.3 °C/W ψJT Junction-to-top characterization parameter 27.2 °C/W ψJB Junction-to-board characterization parameter 54.7 °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance N/A °C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report (SPRA953). 6.5 Power Ratings PARAMETER TEST CONDITIONS PD Maximum power dissipation (both sides) PD1 Maximum power dissipation (side-1) PD2 Maximum power dissipation (side-2) 6 MIN VCC1 = VCC2 = 5.5 V, TJ = 150 °C, C1 = 40 pF, C2 = 400 pF; Input a 1-MHz 50% duty cycle clock signal Submit Documentation Feedback TYP MAX UNIT 85 mW 34 mW 51 mW Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 6.6 Insulation Specifications PARAMETER TEST CONDITIONS VALUE UNIT GENERAL External clearance (1) Shortest terminal-to-terminal distance through air >4 mm CPG External creepage (1) Shortest terminal-to-terminal distance across the package surface >4 mm DTI Distance through the insulation Minimum internal gap (internal clearance) 0.014 mm CTI Comparative tracking index DIN EN 60112 (VDE 0303-11); IEC 60112 >400 V Rated mains voltage ≤ 150 VRMS I–IV Rated mains voltage ≤ 300 VRMS I–III CLR Material group II Overvoltage category DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 VIORM VIOTM Maximum repetitive peak isolation voltage AC voltage (bipolar) Maximum transient isolation voltage Apparent charge (3) qpd Barrier capacitance, input to output (4) CIO Isolation resistance, input to output (4) RIO (2) VTEST = VIOTM t = 60 s (qualification) t = 1 s (100% production) 566 VPK 4242 VPK Method a: After I/O safety test subgroup 2/3, Vini = VIOTM, tini = 60 s; Vpd(m) = 1.2 × VIORM = 680 VPK, tm = 10 s <5 Method a: After environmental tests subgroup 1, Vini = VIOTM, tini = 60 s; Vpd(m) = 1.6 × VIORM = 906 VPK, tm = 10 s <5 Method b1: At routine test (100% production) and preconditioning (type test) Vini = VIOTM, tini = 1 s; Vpd(m) = 1.875 × VIORM = 1062 VPK, tm = 1 s <5 VIO = 0.4 sin (2πft), f = 1 MHz ~1 pC pF 12 VIO = 500 V, TA = 25°C >10 VIO = 500 V, 100°C ≤ TA ≤ 125°C >1011 VIO = 500 V at TS = 150°C >109 Pollution degree 2 Climatic category 40/125/21 Ω UL 1577 VISO (1) (2) (3) (4) Withstand isolation voltage VTEST = VISO = 2500 VRMS, t = 60 s (qualification); VTEST = 1.2 × VISO = 3000 VRMS, t = 1 s (100% production) 2500 VRMS Creepage and clearance requirements should be applied according to the specific equipment isolation standards of an application. Care should be taken to maintain the creepage and clearance distance of a board design to ensure that the mounting pads of the isolator on the printed-circuit board do not reduce this distance. Creepage and clearance on a printed-circuit board become equal in certain cases. Techniques such as inserting grooves and/or ribs on a printed circuit board are used to help increase these specifications. This coupler is suitable for basic electrical insulation only within the maximum operating ratings. Compliance with the safety ratings shall be ensured by means of suitable protective circuits. Apparent charge is electrical discharge caused by a partial discharge (pd). All pins on each side of the barrier tied together creating a two-terminal device Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 7 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 6.7 Safety-Related Certifications VDE CSA UL CQC Certified according to DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 and DIN EN 61010-1 Approved under CSA Component Acceptance Notice 5A, CSA/IEC 60950-1, and CSA/IEC 61010-1 Basic Insulation Maximum Transient Overvoltage, 4242 VPK; Maximum Repetitive Peak Voltage, 566 VPK 2.8-kVRMS Insulation Rating; 400 VRMS Basic Insulation working voltage per CSA 60950-107+A1+A2 and IEC 60950-1 2nd Ed.+A1+A2; Single protection, 2500 VRMS 300 VRMS Basic, 150 VRMS Reinforced Insulation working voltage per CSA 61010-1-12 and IEC 61010-1 3rd Ed., Basic Insulation, Altitude ≤ 5000 m, Tropical Climate, 250 VRMS maximum working voltage Certificate number: 40016131 Master contract number: 220991 Certificate number: CQC14001109540 Recognized under UL 1577 Component Recognition Program File number: E181974 Certified according to GB4943.12011 6.8 Safety Limiting Values Safety limiting intends to minimize potential damage to the isolation barrier upon failure of input or output circuitry. A failure of the I/O can allow low resistance to ground or the supply and, without current limiting, dissipate sufficient power to overheat the die and damage the isolation barrier, potentially leading to secondary system failures. PARAMETER IS TS Safety input, output, or supply current TEST CONDITIONS MIN TYP MAX RθJA = 114.6°C/W, VI = 5.5 V, TJ = 150°C, TA = 25°C, see Figure 1 198 RθJA = 114.6°C/W, VI = 3.6 V, TJ = 150°C, TA = 25°C, see Figure 1 303 Safety temperature UNIT mA 150 °C The safety-limiting constraint is the maximum junction temperature specified in the data sheet. The power dissipation and junction-to-air thermal impedance of the device installed in the application hardware determines the junction temperature. The assumed junction-to-air thermal resistance in the Thermal Information table is that of a device installed on a high-K test board for leaded surface-mount packages. The power is the recommended maximum input voltage times the current. The junction temperature is then the ambient temperature plus the power times the junction-to-air thermal resistance. 8 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 6.9 Electrical Characteristics over recommended operating conditions, unless otherwise noted PARAMETER TEST CONDITIONS MIN TYP MAX UNIT SIDE 1 (ONLY) VILT1 Voltage input threshold low, SDA1 and SCL1 500 550 660 mV VIHT1 Voltage input threshold high, SDA1 and SCL1 540 610 700 mV VHYST1 Voltage input hysteresis VIHT1 –VILT1 40 60 VOL1 Low-level output voltage, SDA1 and SCL1 (1) 0.5 mA ≤ (ISDA1 and ISCL1) ≤ 3.5 mA 650 ΔVOIT1 Low-level output voltage to highlevel input voltage threshold difference, SDA1 and SCL1 (1) (2) 0.5 mA ≤ (ISDA1 and ISCL1) ≤ 3.5 mA 50 mV 800 mV mV SIDE 2 (ONLY) VILT2 Voltage input threshold low, SDA2 and SCL2 0.3 × VCC2 0.4 × VCC2 V VIHT2 Voltage input threshold high, SDA2 and SCL2 0.4 × VCC2 0.5 × VCC2 V VHYST2 Voltage input hysteresis VIHT2 – VILT2 VOL2 Low-level output voltage, SDA2 and SCL2 0.5 mA ≤ (ISDA2 and ISCL2) ≤ 35 mA 0.05 × VCC2 V 0.4 V 10 µA BOTH SIDES |II| Input leakage currents, SDA1, SCL1, SDA2, and SCL2 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2 CI Input capacitance to local ground, SDA1, SCL1, SDA2, and SCL2 VI = 0.4 × sin(2E6πt) + 2.5 V CMTI Common-mode transient immunity See Figure 21 VCCUV VCC undervoltage lockout threshold (3) (1) (2) (3) 0.01 7 pF 25 50 kV/µs 2.1 2.5 2.8 V This parameter does not apply to the ISO1541 SCL1 line as it is unidirectional. ∆VOIT1 = VOL1 – VIHT1. This represents the minimum difference between a Low-Level Output Voltage and a High-Level Input Voltage Threshold to prevent a permanent latch condition that would otherwise exist with bidirectional communication. Any VCC voltages, on either side, less than the minimum will ensure device lockout. Both VCC voltages greater than the maximum will prevent device lockout. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 9 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 6.10 Supply Current Characteristics over recommended operating conditions, unless otherwise noted. For more information, see Figure 19. PARAMETER TEST CONDITIONS MIN TYP MAX VSDA1, VSCL1 = GND1; VSDA2, VSCL2 = GND2; R1, R2 = Open; C1, C2 = Open 2.4 3.6 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2; R1, R2 = Open; C1, C2 = Open 2.5 3.8 VSDA1, VSCL1 = GND1; VSDA2, VSCL2 = GND2; R1, R2 = Open; C1, C2 = Open 2.1 3.3 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2; R1, R2 = Open; C1, C2 = Open 2.3 3.6 VSDA1, VSCL1 = GND1; VSDA2, VSCL2 = GND2; R1, R2 = Open; C1, C2 = Open 1.7 2.7 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2; R1, R2 = Open; C1, C2 = Open 1.9 3.1 VSDA1, VSCL1 = GND1; VSDA2, VSCL2 = GND2; R1,R2 = Open; C1,C2 = Open 3.1 4.7 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2; R1, R2 = Open; C1, C2 = Open 3.1 4.7 VSDA1, VSCL1 = GND1; VSDA2, VSCL2 = GND2; R1, R2 = Open; C1, C2 = Open 2.8 4.4 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2; R1, R2 = Open; C1, C2 = Open 2.9 4.5 VSDA1, VSCL1 = GND1; VSDA2, VSCL2 = GND2; R1, R2 = Open; C1, C2 = Open 2.3 3.7 VSDA1, VSCL1 = VCC1; VSDA2, VSCL2 = VCC2; R1, R2 = Open; C1, C2 = Open 2.5 4 UNIT 3 V ≤ VCC1, VCC2 ≤ 3.6 V ISO1540 ICC1 Supply current, side 1 ISO1541 ICC2 Supply current, side 2 ISO1540 and ISO1541 mA mA 4.5 V ≤ VCC1, VCC2 ≤ 5.5 V ISO1540 ICC1 Supply current, side 1 ISO1541 ICC2 Supply current, side 2 ISO1540 and ISO1541 mA mA 6.11 Timing Requirements tSP Input noise filter tUVLO Time to recover from UVLO 10 2.7 V to 0.9 V; See Figure 22 Submit Documentation Feedback MIN NOM 5 12 30 50 MAX UNIT 110 µs ns Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 6.12 Switching Characteristics over recommended operating conditions, unless otherwise noted PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 3 V ≤ VCC1, VCC2 ≤ 3.6 V Output Signal Fall Time (SDA1, SCL1) See Figure 19 R1 = 953 Ω, C1 = 40 pF 0.7 × VCC1 to 0.3 × VCC1 tf1 tf2 Output Signal Fall Time (SDA2, SCL2) See Figure 19 R2 = 95.3 Ω, C2 = 400 pF tpLH1-2 Low-to-High Propagation Delay, Side 1 to Side 2 tPHL1-2 High-to-Low Propagation Delay, Side 1 to Side 2 PWD1-2 Pulse Width Distortion |tpHL1-2 – tpLH1-2| tPLH2-1 (1) Low-to-High Propagation Delay, Side 2 to Side 1 tPHL2-1 (1) High-to-Low Propagation Delay, Side 2 to Side 1 PWD2-1 (1) Pulse Width Distortion |tpHL2-1 – tpLH2-1| tLOOP1 (1) Round-trip propagation delay on Side 1 See Figure 19 R1 = 953 Ω, R2 = 95.3 Ω, C1, C2 = 10 pF See Figure 20; R1 = 953 Ω, C1 = 40 pF R2 = 95.3 Ω, C2 = 400 pF 8 17 29 0.9 × VCC1 to 900 mV 16 29 48 0.7 × VCC2 to 0.3 × VCC2 14 23 47 0.9 × VCC2 to 400 mV 35 50 100 0.55 V to 0.7 × VCC2 33 65 ns 0.7 V to 0.4 V 90 181 ns 55 123 ns 0.4 × VCC2 to 0.7 × VCC1 47 68 ns 0.4 × VCC2 to 0.9 V 67 109 ns 20 49 ns 100 165 ns 6 11 20 0.4 V to 0.3 × VCC1 ns ns 4.5 V ≤ VCC1, VCC2 ≤ 5.5 V Output Signal Fall Time (SDA1, SCL1) See Figure 19 R1 = 1430 Ω, C1 = 40 pF 0.7 × VCC1 to 0.3 × VCC1 tf1 0.9 × VCC1 to 900 mV 13 21 39 Output Signal Fall Time (SDA2, SCL2) See Figure 19 R2 = 143 Ω, C2 = 400 pF 0.7 × VCC2 to 0.3 × VCC2 10 18 35 tf2 0.9 × VCC2 to 400 mV 28 41 76 tpLH1-2 Low-to-High Propagation Delay, Side 1 to Side 2 0.55 V to 0.7 × VCC2 31 62 ns tPHL1-2 High-to-Low Propagation Delay, Side 1 to Side 2 0.7 V to 0.4 V 70 139 ns PWD1-2 Pulse Width Distortion |tpHL1-2 – tpLH1-2| 38 80 ns tPLH2-1 (1) Low-to-high propagation delay, side 2 to side 1 0.4 × VCC2 to 0.7 × VCC1 55 80 ns tPHL2-1 (1) High-to-low propagation delay, Side 2 to side 1 0.4 × VCC2 to 0.9 V 47 85 ns PWD2-1 (1) Pulse Width Distortion |tpHL2-1 – tpLH2-1| 8 21 ns tLOOP1 (1) Round-trip propagation delay on side 1 110 180 ns (1) See Figure 19 R1 = 1430 Ω, R2 = 143 Ω, C1,2 = 10 pF See Figure 20; R1 = 1430 Ω, C1 = 40 pF R2 = 143 Ω, C2 = 400 pF 0.4 V to 0.3 × VCC1 ns ns This parameter does not apply to the ISO1541 SCL1 line as it is unidirectional. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 11 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 6.13 Insulation Characteristics Curves 350 VCC1 = VCC2 = 3.6 V VCC1 = VCC2 = 5.5 V Safety Limiting Current (mA) 300 250 200 150 100 50 0 0 50 100 150 Ambient Temperature (qC) 200 Figure 1. Thermal Derating Curve for Limiting Current per VDE 12 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 6.14 Typical Characteristics 3.0 0.800 IOL1 = 3.5 mA IOL1 = 0.5 mA 2.5 0.760 Output Current, IOL1 (mA) Output Voltage, VOL1 (V) 0.780 0.740 0.720 0.700 0.680 0.660 0.640 2.0 1.5 1.0 0.5 0.0 0.620 -0.5 0 0.600 −40 −25 −10 5 20 35 50 65 80 Free−Air Temperature (°C) 95 0.4 0.5 0.6 20 20 18 18 16 16 14 14 12 10 8 6 0.8 0.9 R1 = 1430 : R1 = 2.2 k: 12 10 8 6 4 R1= 953 : R1= 2.2 k: 2 -25 -10 VCC1 = 3.3 V 5 20 35 50 65 80 Free-Air Temperature (qC) 95 2 0 -40 110 125 -25 -10 5 D001 C1 = 40 pF Fall time measured from 70% to 30% VCC1 VCC1 = 5 V Figure 4. Side 1: Output Fall Time vs Free-Air Temperature 25 25 Fall Time tf2 (ns) 30 20 15 10 5 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 D002 C1 = 40 pF Fall time measured from 70% to 30% VCC1 Figure 5. Side 1: Output Fall Time vs Free-air Temperature 30 20 15 10 5 R2 = 95.3 : R2 = 2.2 k: 0 -40 0.7 Figure 3. Side 1: Output Low Current vs SDA1 or SCL1 Applied Voltage Fall Time, tf1 (ns) Fall Time, tf1 (ns) 0.3 TA = 25°C 4 Fall Time tf2 (ns) 0.2 Applied Voltage, VSDA1, VSCL1 (V) Figure 2. Side 1: Output Low Voltage vs Free-Air Temperature 0 -40 0.1 110 125 -25 -10 VCC2 = 3.3 V 5 20 35 50 65 80 Free-Air Temperature (qC) 95 R2 = 143 : R2 = 2.2 k: 110 125 0 -40 -25 -10 D003 C2 = 400 pF Fall time measured from 70% to 30% VCC2 Figure 6. Side 2: Output Fall Time vs Free-Air Temperature VCC2 = 5 V 5 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 D004 C2 = 400 pF Fall time measured from 70% to 30% VCC2 Figure 7. Side 2: Output Fall Time vs Free-Air Temperature Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 13 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com Typical Characteristics (continued) 120 45 100 Propagation Delay, tPHL1-2 (ns) Propagation Delay, t PLH1-2 (ns) 40 35 30 25 20 15 10 80 60 40 20 VCC1 and VCC2 = 3.3 V, R2 = 95.3 : VCC1 and VCC2 = 5 V, R2 = 143 : VCC1 and VCC2 = 3.3 V, R2 = 95.3 : VCC1 and VCC2 = 5 V, R2 = 143 : 5 0 -40 -25 -10 5 20 35 50 65 80 Free-Air Temperature (qC) 95 0 -40 110 125 C2 = 10 pF 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 D006 90 VCC1 and VCC2 = 3.3 V VCC1 and VCC2 = 5 V 1045 80 Propagation Delay, t PHL1-2 (ns) Propagation Delay, tPLH1-2 (ns) 5 Figure 9. tPHL1-2 Propagation Delay vs Free-Air Temperature 1050 1040 1035 1030 1025 1020 1015 1010 70 60 50 40 30 20 VCC1 and VCC2 = 3.3 V VCC1 and VCC2 = 5 V 10 1005 1000 -40 -25 -10 5 R2 = 2.2 kΩ 20 35 50 65 80 Free-Air Temperature (qC) 95 0 -40 110 125 C2 = 400 pF 70 Propagation Delay, t PHL2-1 (ns) 60 50 40 30 20 -10 5 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 95 110 125 D008 60 50 40 30 20 VCC1 and VCC2 = 3.3 V, R1 = 953 : VCC1 and VCC2 = 5 V, R1 = 1430 : 0 -40 -25 -10 D009 C1 = 10 pF 20 35 50 65 80 Free-Air Temperature (qC) C2 = 400 pF 10 VCC1 and VCC2 = 3.3 V, R1 = 953 : VCC1 and VCC2 = 5 V, R1 = 1430 : -25 5 Figure 11. tPHL1-2 Propagation Delay vs Free-Air Temperature 80 0 -40 -10 R2 = 2.2 kΩ 70 10 -25 D007 Figure 10. tPLH1-2 Propagation Delay vs Free-Air Temperature Propagation Delay, t PHL2-1 (ns) -10 C2 = 10 pF Figure 8. tPLH1-2 Propagation Delay vs Free-Air Temperature 5 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 D010 C1 = 10 pF Figure 12. tPLH2-1 Propagation Delay vs Free-Air Temperature 14 -25 D005 Figure 13. tPHL2-1 Propagation Delay vs Free-Air Temperature Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 148 80 146 70 Propagation Delay, t PHL2-1 (ns) Propagation Delay, tPLH2-1 (ns) Typical Characteristics (continued) 144 142 140 138 136 134 VCC1 and VCC2 = 3.3 V VCC1 and VCC2 = 5 V 132 -40 -25 -10 5 R1 = 2.2 kΩ 20 35 50 65 80 Free-Air Temperature (qC) 95 60 50 40 30 20 VCC1 and VCC2 = 3.3 V VCC1 and VCC2 = 5 V 10 0 −40 −25 −10 110 125 D011 C1 = 40 pF R1 = 2.2 kΩ Figure 14. tPLH2-1 Propagation Delay vs Free-Air Temperature 5 20 35 50 65 80 Free-Air Temperature (°C) C1 = 40 pF 95 110 125 Figure 15. tPHL2-1 Propagation Delay vs Free-Air Temperature 600 140 120 595 tLOOP1 (ns) tLOOP1 (ns) 100 80 60 590 585 40 580 20 VCC1 and VCC2 = 3.3 V VCC1 and VCC2 = 5 V VCC1 and VCC2 = 3.3 V, R1 = 953 :, R2 = 95.3 : VCC1 and VCC2 = 5 V, R1 = 1430 :, R2 = 143 : 0 -40 -25 -10 C1 = 40 pF 5 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 575 -40 -25 C2 = 400 pF 5 20 35 50 65 80 Free-Air Temperature (qC) C1 = 40 pF R1 = 2.2 kΩ Figure 16. tLOOP1 vs Free-Air Temperature Common-Mode Transient Immunity (kV/Ps) -10 D013 95 110 125 D014 C2 = 400 pF R2 = 2.2 kΩ Figure 17. tLOOP1 vs Free-Air Temperature 70 60 50 40 30 20 10 0 -40 VCC1 and VCC2 = 3.3 V VCC1 and VCC2 = 5 V -25 -10 5 20 35 50 65 80 Free-Air Temperature (qC) 95 110 125 D015 Figure 18. CMTI vs Free-Air Temperature Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 15 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 7 Parameter Measurement Information VCC1 R1 ± + ± + R1 VCC2 R2 SDA1 R2 SDA2 ISO1540 ISO1541 SCL2 SCL1 C1 C1 C2 C2 Copyright © 2016, Texas Instruments Incorporated Figure 19. Test Diagram VCC2 VCC1 SDA1 or SCL1 Output R1 Isolation VCC1 GND1 C1 tLOOP1 0.3 VCC1 SDA1 SCL1 (ISO1540 Only) 0.4 V GND1 Copyright © 2016, Texas Instruments Incorporated Figure 20. tLoop1 Setup and Timing Diagram VCCx VCCy 2k 2k Input Isolation + Output ± GNDx GNDy VCMTI Figure 21. Common-Mode Transient Immunity Test Circuit 16 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 Parameter Measurement Information (continued) VCCy VCCx VCCx Ry SDAx or SCLx I solatio n 0V Side x, Side y VCCx,VCCy Ry 1, 2 3.3 V, 3.3 V 95.3 Ω 2, 1 3.3 V, 3.3 V 953 Ω + Output GNDy GNDx or VCCx VCCy VCCy Ry SDAx or SCLx Isola tion 0V + Output GNDx GNDy VCCx or VCCy 2 .7 V t UVLO 0 .9 V Output Figure 22. tUVLO Test Circuit and Timing Diagrams Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 17 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 8 Detailed Description 8.1 Overview The I2C bus is used in a wide range of applications because it is simple to use. The bus consists of a two-wire communication bus that supports bidirectional data transfer between a master device and several slave devices. The master, or processor, controls the bus, specifically the serial clock (SCL) line. Data is transferred between the master and slave through a serial data (SDA) line. This data can be transferred in four speeds: standard mode (0 to 100 kbps), fast mode (0 to 400 kbps), fast-mode plus (0 to 1 Mbps), and high-speed mode (0 to 3.4 Mbps). The most common speeds are the standard and fast modes. The I2C bus operates in bidirectional, half-duplex mode, while standard digital isolators are unidirectional devices. To make efficient use of one technology supporting the other, external circuitry is required that separates the bidirectional bus into two unidirectional signal paths without introducing significant propagation delay. These devices have their logic input and output buffers separated by TI's capacitive isolation technology using a silicon dioxide (SiO2) barrier. When used in conjunction with isolated power supplies, these devices block high voltages, isolate grounds, and prevent noise currents from entering the local ground and interfering with or damaging sensitive circuitry. 8.2 Functional Block Diagrams VCC1 VCC2 SDA2 VREF Isolation Capacitor SDA1 SCL1 SCL2 GND1 GND2 VREF Figure 23. ISO1540 Block Diagram 18 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 Functional Block Diagrams (continued) VCC2 SDA1 SDA2 Isolation Capacitor VCC1 VREF SCL1 SCL2 GND1 GND2 Figure 24. ISO1541 Block Diagram 8.3 Feature Description The device enables a complete isolated I2C interface to be implemented within a small form factor having the features listed in Table 1. Table 1. Features List (1) PART NUMBER CHANNEL DIRECTION ISO1540 Bidirectional (SCL) Bidirectional (SDA) ISO1541 Unidirectional (SCL) Bidirectional (SDA) RATED ISOLATION (1) MAXIMUM FREQUENCY 2500 VRMS 4242 VPK 1 MHz See Safety-Related Certifications for detailed Isolation specifications. 8.4 Isolator Functional Principle To isolate a bidirectional signal path (SDA or SCL), the ISO1540 internally splits a bidirectional line into two unidirectional signal lines, each of which is isolated through a single-channel digital isolator. Each channel output is made open-drain to comply with the open-drain technology of I2C. Side 1 of the ISO1540 connects to a lowcapacitance I2C node, while side 2 is designed for connecting to a fully loaded I2C bus with up to 400 pF of capacitance. VCC1 VCC2 A R PU1 R PU2 B SDA1 ISO1540 Cnode VC-out SDA2 40 mV Cbus C 50 mV VSDA1 D GND1 V REF GND2 VILT1 VIHT1 VOL1 Copyright © 2016, Texas Instruments Incorporated Figure 25. SDA Channel Design and Voltage Levels at SDA1 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 19 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com Isolator Functional Principle (continued) At first sight, the arrangement of the internal buffers suggests a closed signal loop that is prone to latch-up. However, this loop is broken by implementing an output buffer (B) whose output low-level is raised by a diode drop to approximately 0.75 V, and the input buffer (C) that consists of a comparator with defined hysteresis. The comparator’s upper and lower input thresholds then distinguish between the proper low-potential of 0.4 V (maximum) driven directly by SDA1 and the buffered output low-level of B. Figure 26 demonstrate the switching behavior of the I2C isolator, ISO1540, between a master node at SDA1 and a heavy loaded bus at SDA2. VCC2 VOL1 SDA1 50% SDA2 VIHT1 30% Receive Delay Receive Delay VCC1 Receive Delay Transmit Delay VCC1 VCC2 VCC2 SDA2 50% SDA1 VCC1 VCC1 VCC2 Transmit Delay VIHT2 30% Figure 26. SDA Channel Timing in Receive and Transmit Directions 8.4.1 Receive Direction (Left Diagram of Figure 26) When the I2C bus drives SDA2 low, SDA1 follows after a certain delay in the receive path. The output low is the buffered output of VOL1 = 0.75 V, which is sufficiently low to be detected by Schmitt-trigger inputs with a minimum input-low voltage of VIL = 0.9 V at 3 V supply levels. When SDA2 is released, its voltage potential increases towards VCC2 following the time-constant formed by RPU2 and Cbus. After the receive delay, SDA1 is released and also rises towards VCC1, following the timeconstant RPU1 × Cnode. Because of the significant lower time-constant, SDA1 may reach VCC1 before SDA2 reaches VCC2 potential. 8.4.2 Transmit Direction (Right Diagram of Figure 26) When a master drives SDA1 low, SDA2 follows after a certain delay in the transmit direction. When SDA2 turns low it also causes the output of buffer B to turn low but at a higher 0.75 V level. This level cannot be observed immediately as it is overwritten by the lower low-level of the master. However, when the master releases SDA1, the voltage potential increases and first must pass the upper input threshold of the comparator, VIHT1, to release SDA2. SDA1 then increases further until it reaches the buffered output level of VOL1 = 0.75 V, maintained by the receive path. When comparator C turns high, SDA2 is released after the delay in transmit direction. It takes another receive delay until B’s output turns high and fully releases SDA1 to move toward VCC1 potential. 8.5 Device Functional Modes Table 2 lists the ISO154x functional modes. Table 2. Function Table (1) (1) (2) 20 POWER STATE INPUT OUTPUT Z VCC1 or VCC2 < 2.1 V X VCC1 and VCC2 > 2.8 V L L VCC1 and VCC2 > 2.8 V H Z VCC1 and VCC2 > 2.8 V Z (2) ? H = High Level; L = Low Level; Z = High Impedance or Float; X = Irrelevant; ? = Indeterminate Invalid input condition as an I2C system requires that a pullup resistor to VCC is connected. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 9 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 9.1 Application Information 9.1.1 I2C Bus Overview The inter-integrated circuit (I2C) bus is a single-ended, multi-master, 2-wire bus for efficient inter-IC communication in half-duplex mode. I2C uses open-drain technology, requiring two lines, serial data (SDA) and serial clock (SCL), to be connected to VDD by resistors (see Figure 27). Pulling the line to ground is considered a logic zero while letting the line float is a logic one. This logic is used as a channel access method. Transitions of logic states must occur while the SCL pin is low. Transitions while the SCL pin is high indicate START and STOP conditions. Typical supply voltages are 3.3 V and 5 V, although systems with higher or lower voltages are allowed. VDD RPU RPU RPU RPU RPU RPU RPU RPU SDA SCL SDA SCL SDA GND C Master SCL SDA GND ADC Slave SCL GND DAC Slave SDA SCL GND C Slave Figure 27. I2C Bus I2C communication uses a 7-bit address space with 16 reserved addresses, so a theoretical maximum of 112 nodes can communicate on the same bus. In praxis, however, the number of nodes is limited by the specified, total bus capacitance of 400 pF, which restricts communication distances to a few meters. The specified signaling rates for the ISO1540 and ISO1541 devices are 100 kbps (standard mode), 400 kbps (fast mode), 1 Mbps (fast mode plus). The bus has two roles for nodes: master and slave. A master node issues the clock and slave addresses, and also initiates and ends data transactions. A slave node receives the clock and addresses and responds to requests from the master. Figure 28 shows a typical data transfer between master and slave. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 21 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com Application Information (continued) 7-bit ADDRESS SDA SCL R/W ACK 8 9 1 -7 8-bit DATA 8-bit DATA ACK 1 -8 9 ACK / NACK 1 -8 9 S P START Condition STOP condition Figure 28. Timing Diagram of a Complete Data Transfer The master initiates a transaction by creating a START condition, following by the 7-bit address of the slave it wishes to communicate with. This is followed by a single read and write (R/W) bit, representing whether the master wishes to write to 0, or to read from 1 the slave. The master then releases the SDA line to allow the slave to acknowledge the receipt of data. The slave responds with an acknowledge bit (ACK) by pulling the SDA pin low during the entire high time of the 9th clock pulse on the SCL signal, after which the master continues in either transmit or receive mode (according to the R/W bit sent), while the slave continues in the complementary mode (receive or transmit, respectively). The address and the 8-bit data bytes are sent most significant bit (MSB) first. The START bit is indicated by a high-to-low transition of SDA while SCL is high. The STOP condition is created by a low-to-high transition of SDA while SCL is high. If the master writes to a slave, it repeatedly sends a byte with the slave sending an ACK bit. In this case, the master is in master-transmit mode and the slave is in slave-receive mode. If the master reads from a slave, it repeatedly receives a byte from the slave, while acknowledging (ACK) the receipt of every byte but the last one (see Figure 29). In this situation, the master is in master-receive mode and the slave is in slave-transmit mode. The master ends the transmission with a STOP bit, or may send another START bit to maintain bus control for further transfers. S Slave Address W A From Master to Slave DATA A DATA A P A = acknowledge A = not acknowledge Master Transmitter writing to Slave Receiver S = Start From Slave to Master P = Stop S Slave Address R A DATA A DATA Master Receiver reading from Slave Transmitter A P R = Read W = Write Figure 29. Transmit or Receive Mode Changes During a Data Transfer When writing to a slave, a master mainly operates in transmit-mode and only changes to receive-mode when receiving acknowledgment from the slave. When reading from a slave, the master starts in transmit-mode and then changes to receive-mode after sending a READ request (R/W bit = 1) to the slave. The slave continues in the complementary mode until the end of a transaction. NOTE The master ends a reading sequence by not acknowledging (NACK) the last byte received. This procedure resets the slave state machine and allows the master to send the STOP command. 22 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 9.2 Typical Application In Figure 30, the ultra low-power microcontroller, MSP430G2132, controls the I2C data traffic of configuration data and conversion results for the analog inputs and outputs. Low-power data converters build the analog interface to sensors and actuators. The ISO1541 device provides the required isolation between different ground potentials of the system controller, remote sensor, and actuator circuitry to prevent ground loop currents that otherwise may falsify the acquired data. The entire circuit operates from a single 3.3-V supply. A low-power push-pull converter, SN6501, drives a centertapped transformer with an output that is rectified and linearly regulated to provide a stable 5-V supply for the data converter. VS 3.3V 0.1 μF 2 Vcc D2 1:2.2 3 MBR0520L 1 SN6501 GND D1 10 μF 0.1 μF OUT 5 ON GND 5VISO 0.1 μF 8 10 μF LP2981-50 3 1 4,5 IN 9 2 10 1Ω 10 μF 1 MBR0520L VDD SDA AIN0 4 4 Analog Inputs SCL ADS 1115 ADDR AIN3 GND RDY 3 7 2 SCL 5VISO SDA 5VISO ISO- BARRIER 5VISO 0.1 μF 6 22 μF VOUT VIN 2 1 μF REF5040 4 GND 0.1 μF 0.1 μF 1.5 kΩ 1.5 kΩ 2 5 6 1 VCC1 DVcc XOUT XIN MSP430 SDA G2132 SCL 9 8 DVss 2 1.5 kΩ 8 VCC2 7 SDA2 ISO1541 3 6 SCL1 SCL2 SDA1 GND1 4 0.1 μF 1.5 kΩ 4 GND2 5 3 15 4 12 A2 VDD IOVDD VREFH 1 SDA VOUTA 10 SCL DAC8574 9 LDAC 14 VOUTD A1 8 A0 A3 GND VREFL 11 13 16 6 4 Analog Outputs 5 Copyright © 2016, Texas Instruments Incorporated Figure 30. Isolated I2C Data Acquisition System 9.2.1 Design Requirements The recommended power supply voltages (VCC1 and VCC2) must be from 3 V to 5.5 V. A recommended decoupling capacitor with a value of 0.1 µF is required between both the VCC1 and GND1 pins, and the VCC2 and GND2 pins to support of power supply voltages transient and to ensure reliable operation at all data rates. 9.2.2 Detailed Design Procedure The power-supply capacitor with a value of 0.1-µF must be placed as close to the power supply pins as possible. The recommended placement of the capacitors must be 2-mm maximum from input and output power supply pins (VCC1 and VCC2). The maximum load permissible on the input lines, SDA1 and SCL1, is ≤ 40 pF and on the output lines, SDA2 and SCL2, is ≤ 400 pF. The minimum pullup resistors on the input lines, SDA1 and SCL1 to VCC1 must be selected in such a way that input current drawn is ≤ 3.5 mA. The minimum pullup resistors on the input lines, SDA2 and SCL2, to VCC2 must be selected in such a way that output current drawn is ≤ 35 mA. The maximum pullup resistors on the input lines (SDA1 and SCL1) to VCC1 and on output lines (SDA1 and SCL1) to VCC2, depends on the load and rise time requirements on the respective lines. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 23 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com Typical Application (continued) ISO1540 2mm maximum 2 mm maximum VCC1 VCC2 8 1 10 …F 1k SDA1 10 …F Isolation Capacitor 1k 2 SCL1 3 1k 1k SDA2 7 SCL2 6 GND1 4 GND2 5 Side 1 Side 2 Copyright © 2016, Texas Instruments Incorporated Figure 31. Typical ISO1540 Circuit Hookup ISO1541 2mm maximum 2 mm maximum VCC1 VCC2 8 1 10 …F 1k SDA1 10 …F Isolation Capacitor 1k 2 SCL1 3 1k 1k SDA2 7 SCL2 6 GND1 4 5 Side 1 GND2 Side 2 Copyright © 2016, Texas Instruments Incorporated Figure 32. Typical ISO1541 Circuit Hookup 9.2.3 Application Curve o 500 mV/div TA = 25 C VCC1 = 3.6 V 900 mV VOL1 GND1 Time - 50 ns/div Figure 33. Side 1: Low-to-High Transition 24 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 10 Power Supply Recommendations To help ensure reliable operation at data rates and supply voltages, TI recommends connecting a 0.1-µF bypass capacitor at the input and output supply pins (VCC1 and VCC2). The capacitors should be placed as close to the supply pins as possible. If only a single, primary-side power supply is available in an application, isolated power can be generated for the secondary-side with the help of a transformer driver such as TI's SN6501 device. For such applications, detailed power supply design and transformer selection recommendations are available in SN6501 Transformer Driver for Isolated Power Supplies. (SLLSEA0). 11 Layout 11.1 Layout Guidelines A minimum of four layers is required to accomplish a low EMI PCB design (see Figure 34). Layer stacking should be in the following order (top-to-bottom): high-speed signal layer, ground plane, power plane and low-frequency signal layer. • Routing the high-speed traces on the top layer avoids the use of vias (and the introduction of their inductances) and allows for clean interconnects between the isolator and the transmitter and receiver circuits of the data link. • Placing a solid ground plane next to the high-speed signal layer establishes controlled impedance for transmission line interconnects and provides an excellent low-inductance path for the return current flow. • Placing the power plane next to the ground plane creates additional high-frequency bypass capacitance of approximately 100 pF/in2. • Routing the slower speed control signals on the bottom layer allows for greater flexibility as these signal links usually have margin to tolerate discontinuities such as vias. If an additional supply voltage plane or signal layer is needed, add a second power or ground plane system to the stack to keep it symmetrical. This makes the stack mechanically stable and prevents it from warping. Also the power and ground plane of each power system can be placed closer together, thus increasing the high-frequency bypass capacitance significantly. For detailed layout recommendations, see the Digital Isolator Design Guide (SLLA284) 11.1.1 PCB Material For digital circuit boards operating at less than 150 Mbps, (or rise and fall times greater than 1 ns), and trace lengths of up to 10 inches, use standard FR-4 UL94V-0 printed circuit board. This PCB is preferred over cheaper alternatives because of lower dielectric losses at high frequencies, less moisture absorption, greater strength and stiffness, and the self-extinguishing flammability-characteristics. 11.2 Layout Example High-speed traces 10 mils Ground plane 40 mils Keep this space free from planes, traces, pads, and vias FR-4 0r ~ 4.5 Power plane 10 mils Low-speed traces Figure 34. Recommended Layer Stack Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 25 ISO1540, ISO1541 SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 www.ti.com 12 Device and Documentation Support 12.1 Documentation Support 12.1.1 Related Documentation For related documentation see the following: • Digital Isolator Design Guide (SLLA284) • ISO154xEVM Low-Power Bidirectional I2C Isolators Evaluation Module (SLLU166) • TI Isolation Glossary (SLLA353) • SN6501 Transformer Driver for Isolated Power Supplies. (SLLSEA0) 12.2 Related Links The table below lists quick access links. Categories include technical documents, support and community resources, tools and software, and quick access to sample or buy. Table 3. Related Links PARTS PRODUCT FOLDER SAMPLE & BUY TECHNICAL DOCUMENTS TOOLS & SOFTWARE SUPPORT & COMMUNITY ISO1540 Click here Click here Click here Click here Click here ISO1541 Click here Click here Click here Click here Click here 12.3 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 12.4 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 12.5 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 12.6 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 12.7 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 26 Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 ISO1540, ISO1541 www.ti.com SLLSEB6D – JULY 2012 – REVISED DECEMBER 2016 13 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Submit Documentation Feedback Copyright © 2012–2016, Texas Instruments Incorporated Product Folder Links: ISO1540 ISO1541 27 PACKAGE OPTION ADDENDUM www.ti.com 15-Apr-2017 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) HPA02222DR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -40 to 125 IS1540 ISO1540D ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -40 to 125 IS1540 ISO1540DR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -40 to 125 IS1540 ISO1541D ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -40 to 125 IS1541 ISO1541DR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -40 to 125 IS1541 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 15-Apr-2017 (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. 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OTHER QUALIFIED VERSIONS OF ISO1540, ISO1541 : • Automotive: ISO1540-Q1, ISO1541-Q1 NOTE: Qualified Version Definitions: • Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 21-Nov-2016 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant ISO1540DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 ISO1541DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 21-Nov-2016 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) ISO1540DR SOIC D 8 2500 367.0 367.0 38.0 ISO1541DR SOIC D 8 2500 367.0 367.0 38.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated (TI) reserves the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. 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