Si840x B IDIRECTIONAL I 2 C I SOLA TORS WITH U NIDIRECTIONAL D IGITA L C HANNELS Features Independent, bidirectional SDA and SCL isolation channels Open drain outputs with 35 mA sink current 60-year life at rated working voltage High electromagnetic immunity Wide operating supply voltage 3.0 to 5.5 V I2C clocks up to 1.7 MHz Wide temperature range -40 to +125 C max Unidirectional isolation channels support additional system signals Transient immunity 25 kV/s (Si8405) RoHS-compliant packages Up to 2500 VRMS isolation SOIC-8 narrow body SOIC-16 narrow body UL, CSA, VDE recognition Supports Applications Isolated I2C, PMBus, SMBus Power over Ethernet Motor Control Systems Hot-swap applications Intelligent Power systems Isolated SMPS systems with PMBus interfaces Description The Si840x series of isolators are single-package galvanic isolation solutions for I2C and SMBus serial port applications. These products are based on Silicon Labs proprietary RF isolation technology and offer shorter propagation delays, lower power consumption, smaller installed size, and more stable operation with temperature and age versus opto couplers or other digital isolators. Ordering Information: See page 25. All devices in this family include hot-swap, bidirectional SDA and SCL isolation channels with open-drain, 35 mA sink capability and operate to a maximum frequency of 1.7 MHz. The 8-pin version (Si8400) supports bidirectional SDA and SCL isolation; the Si8401/2 support bidirectional SDA and unidirectional SCL isolation, and the 16-pin version (Si8405) features two unidirectional isolation channels to support additional system signals, such as an interrupt or reset. All versions contain protection circuits to guard against data errors if an unpowered device is inserted into a powered system. Small size, low installed cost, low power consumption, and short propagation delays make the Si840x family the optimum solution for isolating I2C and SMBus serial ports. Safety Regulatory Approval UL 1577 recognized Up to 2500 VRMS for 1 minute CSA component notice 5A approval IEC 60950-1, 61010-1 (reinforced insulation) Rev. 1.4 12/11 VDE certification conformity IEC 60747-5-2 (VDE0884 Part 2) Copyright (c) 2011 by Silicon Laboratories Si840x Si840x 2 Rev. 1.4 Si840x TABLE O F C ONTENTS Section Page 1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 1.1. Test Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1. Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3. Device Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.1. Device Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 3.2. Under Voltage Lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.3. Layout Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.4. Input and Output Characteristics for Non-I2C Digital Channels . . . . . . . . . . . . . . . . 15 3.5. Typical Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4. Typical Application Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.1. I2C Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.2. I2C Isolator Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.3. I2C Isolator Design Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.4. I2C Isolator Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5. Errata and Design Migration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5.1. Power Supply Bypass Capacitors (Revision A and Revision B) . . . . . . . . . . . . . . . . 22 6. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 7. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 8. Package Outline: 8-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 9. Land Pattern: 8-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 10. Package Outline: 16-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 11. Land Pattern: 16-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 12. Top Marking: 8-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 12.1. 8-Pin Narrow Body SOIC Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 12.2. Top Marking Explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 13. Top Marking: 16-Pin Narrow Body SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 13.1. 16-Pin Narrow Body SOIC Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 13.2. Top Marking Explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Rev. 1.4 3 Si840x 1. Electrical Specifications Table 1. Absolute Maximum Ratings1 Parameter Symbol Min Typ Max Unit TSTG -65 -- 150 C TA -40 -- 125 C Supply Voltage (Revision A)3 VDD -0.5 -- 5.75 V B)3 VDD -0.5 -- 6.0 V Input Voltage VI -0.5 -- VDD + 0.5 V Output Voltage VO -0.5 -- VDD + 0.5 V IO -- -- 10 mA channels) IO -- -- 15 mA Side B output current drive (I2C channels) IO -- -- 75 mA Lead Solder Temperature (10 s) -- -- 260 C Maximum Isolation Voltage (1 s) -- -- 3600 VRMS Storage Temperature2 Ambient Temperature Under Bias Supply Voltage (Revision Output Current Drive (non-I2C channels) Side A output current drive (I2C Notes: 1. Permanent device damage may occur if the absolute maximum ratings are exceeded. Functional operation should be restricted to conditions as specified in the operational sections of this data sheet. 2. VDE certifies storage temperature from -40 to 150 C. 3. See "7.Ordering Guide" on page 25 for more information. Table 2. Si840x Power Characteristics* 3.0 V < VDD < 5.5 V. TA = -40 to +125 C. Typical specs at 25 C (See Figures 2 and 16 for test diagrams.) Parameter Symbol Test Condition Min Typ Max Unit AVDD current BVDD current Idda Iddb All channels = 0 dc -- -- 4.2 3.9 6.3 5.9 mA mA AVDD current BVDD current Idda Iddb All channels = 1 dc -- -- 2.3 1.9 3.5 2.9 mA mA AVDD current BVDD current Idda Iddb All channels = 1.7 MHz -- -- 3.2 2.9 4.8 4.4 mA mA AVDD current BVDD current Idda Iddb All non-I2C channels = 0 All I2C channels = 1 -- -- 3.2 2.9 4.8 4.4 mA mA AVDD current BVDD current Idda Iddb All non-I2C channels = 1 All I2C channels = 0 -- -- 6.2 6.0 9.3 9.0 mA mA AVDD current BVDD current Idda Iddb All non-I2C channels = 5 MHz All I2C channels = 1.7 MHz -- -- 4.7 4.5 7.1 6.8 mA mA Si8400/01/02 Supply Current Si8405 Supply Current *Note: All voltages are relative to respective ground. 4 Rev. 1.4 Si840x Table 3. Si8400/01/02/05 Electrical Characteristics for Bidirectional I2C Channels1 3.0 V < VDD < 5.5 V. TA = -40 to +125 C. Typical specs at 25 C unless otherwise noted. Parameter Test Condition Min Typ Max Unit ISDAA = ISCLA = 3.0 mA ISDAA = ISCLA = 0.5 mA I2CV (Side A) 450 650 550 50 -- -- -- -- 780 910 825 -- mV mV mV mV Logic Levels Side B Logic Low Input Voltage Logic High Input Voltage Logic Low Output Voltage I2CVIL (Side B) I2CVIH (Side B) I2CVOL (Side B) ISCLB = 35 mA -- 2.0 -- -- -- -- 0.8 -- 400 V V mV SCL and SDA Logic High Leakage Isdaa, Isdab Iscla, Isclb SDAA, SCLA = VSSA SDAB, SCLB = VSSB -- 2.0 10 A -- -- 10 10 -- -- pF pF Logic Levels Side A Logic Input Threshold2 Logic Low Output Voltages3 Input/Output Logic Low Level Difference4 Pin capacitance SDAA, SCLA, SDAB, SDBB Symbol I2CVT (Side A) I CVOL (Side A) 2 CA CB Notes: 1. All voltages are relative to respective ground. 2. VIL < 0.450 V, VIH > 0.780 V. 3. Logic low output voltages are 910 mV max from -10 to 125 C at 3.0 mA. Logic low output voltages are 955 mV max from -40 to 125 C at 3.0 mA. Logic low output voltages are 825 mV max from -10 to 125 C at 0.5 mA. Logic low output voltages are 875 mV max from -40 to 125 C at 0.5 mA. See "AN375: Design Considerations for Isolating an I2C Bus or SMBus" for additional information. 4. I2CV (Side A) = I2CVOL (Side A) - I2CVT (Side A). To ensure no latch-up on a given bus, I2CV (Side A) is the minimum difference between the output logic low level of the driving device and the input logic threshold. 5. Side A measured at 0.6 V. Rev. 1.4 5 Si840x Table 3. Si8400/01/02/05 Electrical Characteristics for Bidirectional I2C Channels1 (Continued) 3.0 V < VDD < 5.5 V. TA = -40 to +125 C. Typical specs at 25 C unless otherwise noted. Parameter Symbol Test Condition Min Typ Max Unit -- -- 1.7 MHz Timing Specifications (Measured at 1.40 V Unless Otherwise Specified) Maximum I2C bus Frequency Propagation Delay 5 V Operation Side A to side B rising5 Side A to side B falling5 Side B to side A rising Side B to side A falling 3.3 V Operation Side A to side B rising5 Side A to side B falling5 Side B to side A rising Side B to side A falling Pulse width distortion 5V Side A low to Side B low5 Side B low to Side A low 3.3 V Side A low to Side B low5 Side B low to Side A low Fmax Tphab Tplab Tphba Tplba No bus capacitance, R1 = 1400, R2 = 499, See Figure 2 -- -- -- -- 25 15 20 9.0 29 22 30 12 ns ns ns ns Tphab Tplab Tphba Tplba R1 = 806 R2 = 499 -- -- -- -- 28 13 20 10 35 18 40 15 ns ns ns ns PWDAB PWDBA No bus capacitance, R1 = 1400, R2 = 499, See Figure 2 -- -- 9.0 11 15 20 ns ns PWDAB PWDBA R1 = 806, R2 = 499 -- -- 15 11 22 30 ns ns Notes: 1. All voltages are relative to respective ground. 2. VIL < 0.450 V, VIH > 0.780 V. 3. Logic low output voltages are 910 mV max from -10 to 125 C at 3.0 mA. Logic low output voltages are 955 mV max from -40 to 125 C at 3.0 mA. Logic low output voltages are 825 mV max from -10 to 125 C at 0.5 mA. Logic low output voltages are 875 mV max from -40 to 125 C at 0.5 mA. See "AN375: Design Considerations for Isolating an I2C Bus or SMBus" for additional information. 4. I2CV (Side A) = I2CVOL (Side A) - I2CVT (Side A). To ensure no latch-up on a given bus, I2CV (Side A) is the minimum difference between the output logic low level of the driving device and the input logic threshold. 5. Side A measured at 0.6 V. 6 Rev. 1.4 Si840x Table 4. Electrical Characteristics for Unidirectional Non-I2C Digital Channels (Si8402/05) 3.0 V < VDD < 5.5 V. TA = -40 to +125 C. Typical specs at 25 C Parameter Symbol Test Condition Min Typ Max Unit High Level Input Voltage VIH 2.0 -- -- V Low Level Input Voltage VIL -- -- 0.8 V High Level Output Voltage VOH loh = -4 mA AVDD, BVDD -0.4 4.8 -- V Low Level Output Voltage VOL lol = 4 mA -- 0.2 0.4 V IL -- -- 10 A ZO -- 85 -- Maximum Data Rate 0 -- 10 Mbps Minimum Pulse Width -- -- 40 ns Input Leakage Current 1 Output Impedance Timing Characteristics Propagation Delay Pulse Width Distortion |tPLH - tPHL| Propagation Delay Skew2 Channel-Channel Skew tPHL, tPLH See Figure 1 -- -- 20 ns PWD See Figure 1 -- -- 12 ns tPSK(P-P) -- -- 20 ns tPSK -- -- 10 ns Output Rise Time tr C3 = 15 pF See Figure 1 and Figure 2 -- 4.0 6.0 ns Output Fall Time tf C3 = 15 pF See Figure 1 and Figure 2 -- 3.0 4.3 ns Notes: 1. The nominal output impedance of a non-I2C isolator driver channel is approximately 85 , 40%, which is a combination of the value of the on-chip series termination resistor and channel resistance of the output driver FET. When driving loads where transmission line effects will be a factor, output pins should be appropriately terminated with controlled impedance PCB traces. 2. tPSK(P-P) is the magnitude of the difference in propagation delay times measured between different units operating at the same supply voltages, load, and ambient temperature. Rev. 1.4 7 Si840x Table 5. Electrical Characteristics for All I2C and Non-I2C Channels 3.0 V < VDD < 5.5 V. TA = -40 to +125 C. Typical specs at 25 C Parameter Symbol Test Conditions Min Typ Max Units VDD Undervoltage Threshold VDDUV+ AVDD, BVDD rising 2.15 2.3 2.5 V VDD Negative-going Lockout Hysteresis VDDH- AVDD, BVDD falling 45 75 95 mV CMTI VI = VDD or 0 V -- 25 -- kV/s tSD -- 3.0 -- s tSTART -- 15 40 s Common Mode Transient Immunity Shut Down Time from UVLO Start-up Time* *Note: Start-up time is the time period from the application of power to valid data at the output. 1.4 V Typical Input tPLH tPHL 90% 90% 10% 10% 1.4 V Typical Output tr tf Figure 1. Propagation Delay Timing (Non-I2C Channels) 1.1. Test Circuits Figure 2 depicts the timing test diagram. AVDD R1 R1 BVDD NC ASDA BSDA ADIN BDOUT ADOUT BDIN ASCL BSCL NC C1 C1 R2 NC NC C3 C3 C2 AGND BGND Si840x Figure 2. Simplified Timing Test Diagram 8 R2 Rev. 1.4 C2 Si840x Table 6. Regulatory Information* CSA The Si84xx is certified under CSA Component Acceptance Notice 5A. For more details, see File 232873. 61010-1: Up to 300 VRMS reinforced insulation working voltage; up to 600 VRMS basic insulation working voltage. 60950-1: Up to 130 VRMS reinforced insulation working voltage; up to 600 VRMS basic insulation working voltage. VDE The Si84xx is certified according to IEC 60747-5-2. For more details, see File 5006301-4880-0001. 60747-5-2: Up to 560 Vpeak for basic insulation working voltage. UL The Si84xx is certified under UL1577 component recognition program. For more details, see File E257455. Rated up to 2500 VRMS isolation voltage for basic insulation. *Note: Regulatory Certifications apply to 2.5 kVRMS rated devices which are production tested to 3.0 kVRMS for 1 sec. For more information, see "7.Ordering Guide" on page 25. Table 7. Insulation and Safety-Related Specifications Parameter Symbol Test Condition Value Unit NB SOIC-8 NB SOIC-16 Nominal Air Gap (Clearance)1 L(1O1) 4.9 4.9 mm Nominal External Tracking (Creepage)1 L(1O2) 4.01 4.01 mm 0.008 0.008 mm 600 600 VRMS Minimum Internal Gap (Internal Clearance) Tracking Resistance (Proof Tracking Index) PTI Erosion Depth ED 0.040 0.019 mm Resistance (Input-Output)2 RIO 1012 1012 1.0 2.0 pF 4.0 4.0 pF Capacitance (Input-Output)2 Input Capacitance3 IEC60112 CIO f = 1 MHz CI Notes: 1. The values in this table correspond to the nominal creepage and clearance values as detailed in "8. Package Outline: 8-Pin Narrow Body SOIC" and "10. Package Outline: 16-Pin Narrow Body SOIC". VDE certifies the clearance and creepage limits as 4.7 mm minimum for the NB SOIC-8 package and 4.7 mm minimum for the NB SOIC-16 package. UL does not impose a clearance and creepage minimum for component level certifications. CSA certifies the clearance and creepage limits as 3.9 mm minimum for the NB SOIC-8 package and 3.9 mm minimum for the NB SOIC-16 package. 2. To determine resistance and capacitance, the Si840x, SO-16, is converted into a 2-terminal device. Pins 1-8 (1-4, SO8) are shorted together to form the first terminal and pins 9-16 (5-8, SO-8) are shorted together to form the second terminal. The parameters are then measured between these two terminals. 3. Measured from input pin to ground. Rev. 1.4 9 Si840x Table 8. IEC 60664-1 (VDE 0844 Part 2) Ratings Parameter Basic Isolation Group Installation Classification Test Conditions Specification Material Group I Rated Mains Voltages < 150 VRMS I-IV Rated Mains Voltages < 300 VRMS I-III Rated Mains Voltages < 400 VRMS I-II Rated Mains Voltages < 600 VRMS I-II Table 9. IEC 60747-5-2 Insulation Characteristics for Si84xxxB* Parameter Maximum Working Insulation Voltage Symbol Test Condition Unit 560 V peak VIORM Input to Output Test Voltage Transient Overvoltage Characteristic V peak VPR Method b1 (VIORM x 1.875 = VPR, 100% Production Test, tm = 1 sec, Partial Discharge < 5 pC) 1050 VIOTM t = 60 sec 4000 2 Pollution Degree (DIN VDE 0110, Table 1) Insulation Resistance at TS, VIO = 500 V V peak >109 RS *Note: Maintenance of the safety data is ensured by protective circuits. The Si84xx provides a climate classification of 40/125/21. Table 10. IEC Safety Limiting Values1 Parameter Symbol Case Temperature TS Safety Input Current IS Device Power Dissipation2 PD Test Condition JA = 105 C/W (NB SOIC-16), 140 C/W (NB SOIC-8) AVDD, BVDD = 5.5 V, TJ = 150 C, TA = 25 C NB NB SOIC-8 SOIC-16 Unit 150 150 C 160 210 mA 220 275 W Notes: 1. Maximum value allowed in the event of a failure. Refer to the thermal derating curve in Figure 3 and Figure 4. 2. The Si840x is tested with AVDD, BVDD = 5.5 V; TJ = 150 C; C1, C2 = 0.1 F; C3 = 15 pF; R1, R2 = 3kinput 1 MHz 50% duty cycle square wave. 10 Rev. 1.4 Si840x Table 11. Thermal Characteristics Parameter Symbol JA IC Junction-to-Air Thermal Resistance Safety-Limiting Values (mA) Test Condition NB SOIC-8 NB SOIC-16 Unit 140 105 C/W 400 300 270 200 AVDD, BVDD = 3.6 V 160 AVDD, BVDD = 5.5 V 100 0 0 50 100 150 Case Temperature (C) 200 Figure 3. NB SOIC-8 Thermal Derating Curve, Dependence of Safety Limiting Values with Case Temperature per DIN EN 60747-5-2 Safety-Limiting Current (mA) 500 400 350 300 AVDD , BVDD = 3.6 V 210 200 AVDD , BVDD = 5.5 V 100 0 0 50 100 Temperature (C) 150 200 Figure 4. NB SOIC-16 Thermal Derating Curve, Dependence of Safety Limiting Values with Case Temperature per DIN EN 60747-5-2 Rev. 1.4 11 Si840x 2. Functional Description 2.1. Theory of Operation The operation of an Si84xx channel is analogous to that of an opto coupler, except an RF carrier is modulated instead of light. This simple architecture provides a robust isolated data path and requires no special considerations or initialization at start-up. A simplified block diagram for a single unidirectional Si84xx channel is shown in Figure 5. Transmitter Receiver RF OSCILLATOR A MODULATOR SemiconductorBased Isolation Barrier DEMODULATOR B Figure 5. Simplified Channel Diagram A channel consists of an RF Transmitter and RF Receiver separated by a semiconductor-based isolation barrier. Referring to the Transmitter, input A modulates the carrier provided by an RF oscillator using on/off keying. The Receiver contains a demodulator that decodes the input state according to its RF energy content and applies the result to output B via the output driver. This RF on/off keying scheme is superior to pulse code schemes as it provides best-in-class noise immunity, low power consumption, and better immunity to magnetic fields. See Figure 6 for more details. Input Signal Modulation Signal Output Signal Figure 6. Modulation Scheme 12 Rev. 1.4 Si840x 3. Device Operation Device behavior during start-up, normal operation, and shutdown is shown in Figure 7, where UVLO+ and UVLO- are the positive-going and negative-going thresholds respectively. Refer to Table 12 to determine outputs when power supply (VDD) is not present. 3.1. Device Startup Outputs are held low during powerup until VDD is above the UVLO threshold for time period tSTART. Following this, the outputs follow the states of inputs. 3.2. Under Voltage Lockout Under Voltage Lockout (UVLO) is provided to prevent erroneous operation during device startup and shutdown or when VDD is below its specified operating circuits range. Both Side A and Side B each have their own under voltage lockout monitors. Each side can enter or exit UVLO independently. For example, Side A unconditionally enters UVLO when AVDD falls below AVDDUVLO- and exits UVLO when AVDD rises above AVDDUVLO+. Side B operates the same as Side A with respect to its BVDD supply. UVLO+ UVLO- AVDD UVLO+ UVLO- BVDD INPUT tSTART tSD tSTART tSTART tPHL tPLH OUTPUT Figure 7. Device Behavior during Normal Operation Rev. 1.4 13 Si840x 3.3. Layout Recommendations To ensure safety in the end user application, high voltage circuits (i.e., circuits with >30 VAC) must be physically separated from the safety extra-low voltage circuits (SELV is a circuit with <30 VAC) by a certain distance (creepage/clearance). If a component, such as a digital isolator, straddles this isolation barrier, it must meet those creepage/clearance requirements and also provide a sufficiently large high-voltage breakdown protection rating (commonly referred to as working voltage protection). Table 6 on page 9 and Table 7 on page 9 detail the working voltage and creepage/clearance capabilities of the Si84xx. These tables also detail the component standards (UL1577, IEC60747, CSA 5A), which are readily accepted by certification bodies to provide proof for end-system specifications requirements. Refer to the end-system specification (61010-1, 60950-1, etc.) requirements before starting any design that uses a digital isolator. The following sections detail the recommended bypass and decoupling components necessary to ensure robust overall performance and reliability for systems using the Si84xx digital isolators. 3.3.1. Supply Bypass Digital integrated circuit components typically require 0.1 F (100 nF) bypass capacitors when used in electrically quiet environments. However, digital isolators are commonly used in hazardous environments with excessively noisy power supplies. To counteract these harsh conditions, it is recommended that an additional 1 F bypass capacitor be added between VDD and GND on both sides of the package. The capacitors should be placed as close as possible to the package to minimize stray inductance. If the system is excessively noisy, it is recommended that the designer add 50 to 100 resistors in series with the VDD supply voltage source and 50 to 300 resistors in series with the digital inputs/outputs (see Figure 8). For more details, see "5.Errata and Design Migration Guidelines" on page 22. All components upstream or downstream of the isolator should be properly decoupled as well. If these components are not properly decoupled, their supply noise can couple to the isolator inputs and outputs, potentially causing damage if spikes exceed the maximum ratings of the isolator (6 V). In this case, the 50 to 300 resistors protect the isolator's inputs/outputs (note that permanent device damage may occur if the absolute maximum ratings are exceeded). Functional operation should be restricted to the conditions specified in Table 3, "Si8400/01/02/05 Electrical Characteristics for Bidirectional I2C Channels1," on page 5. and Table 4, "Electrical Characteristics for Unidirectional Non-I2C Digital Channels (Si8402/05)," on page 7 3.3.2. Pin Connections No connect pins are not internally connected. They can be left floating, tied to VDD, or tied to GND. 3.3.3. Output Pin Termination The nominal output impedance of an non-I2C isolator driver channel is approximately 85 , 40%, which is a combination of the value of the on-chip series termination resistor and channel resistance of the output driver FET. When driving loads where transmission line effects will be a factor, output pins should be appropriately terminated with controlled impedance PCB traces. The series termination resistor values should be scaled appropriately while keeping in mind the recommendations described in "3.3.1. Supply Bypass" above. V Source 2 V Source 1 R1 (50 - 100 ) R2 (50 - 100 ) AVDD C1 BVDD 50 - 300 0.1 F Ax 0.1 F Bx C2 1 F C4 50 - 300 C3 Input/Output Input/Output 1 F Bx Ax 50 - 300 50 - 300 AGND BGND Figure 8. Recommended Bypass Components for the Si84xx Digital Isolator Family 14 Rev. 1.4 Si840x 3.4. Input and Output Characteristics for Non-I2C Digital Channels The Si84xx inputs and outputs for unidirectional channels are standard CMOS drivers/receivers. The nominal output impedance of an isolator driver channel is approximately 85 , 40%, which is a combination of the value of the on-chip series termination resistor and channel resistance of the output driver FET. When driving loads where transmission line effects will be a factor, output pins should be appropriately terminated with controlled impedance PCB traces. Table 12 details powered and unpowered operation of the Si84xx's non-I2C digital channels. Table 12. Si84xx Operation Table VI Input1,2 VDDI State1,3,4 VDDO State1,3,4 VO Output1,2 H P P H L P P L X5 UP P L6 X5 P UP Comments Normal operation. Upon transition of VDDI from unpowered to powered, VO returns to the same state as VI in less than 1 s. Upon transition of VDDO from unpowered to powUndetermined ered, VO returns to the same state as VI within 1 s. Notes: 1. VDDI and VDDO are the input and output power supplies. VI and VO are the respective input and output terminals. 2. X = not applicable; H = Logic High; L = Logic Low. 3. Powered (P) state is defined as 3.0 V < VDD < 5.5 V. 4. Unpowered (UP) state is defined as VDD = 0 V. 5. Note that an I/O can power the die for a given side through an internal diode if its source has adequate current. 6. For I2C channels, the outputs for a given side go to Hi-Z when power is lost on the opposite side. Rev. 1.4 15 Si840x 3.5. Typical Performance Characteristics The typical performance characteristics depicted in the following diagrams are for information purposes only. Refer to Tables 2, 3, 4, and 5 for actual specification limits. Side A Side B Side B Side A Figure 12. I2C Side A Pulling Up, Side B Following Figure 9. I2C Side A Pulling Down (1100 Pull-Up) 10 Falling Edge Side B Side A Delay (ns) 9 8 7 Rising Edge 6 5 -40 -20 0 20 40 60 80 100 120 Temperature (Degrees C) Figure 10. I2C Side B Pulling Down Side B Figure 13. Non I2C Channel Propagation Delay vs. Temperature Side A Figure 11. I2C Side B Pulling Up, Side A Following 16 Rev. 1.4 Si840x Figure 14. Si84xx Time-Dependent Dielectric Breakdown Rev. 1.4 17 Si840x 4. Typical Application Overview 4.1. I2C Background In many applications, I2C, SMBus, and PMBus interfaces require galvanic isolation for safety or ground loop elimination. For example, Power over Ethernet (PoE) applications typically use an I2C interface for communication between the PoE power sourcing device (PSE), and the earth ground referenced system controller. Galvanic isolation is required both by standard and also as a practical matter to prevent ground loops in Ethernet connected equipment. The physical interface consists of two wires: serial data (SDA) and serial clock (SCL). These wires are connected to open collector drivers that serve as both inputs and outputs. At first glance, it appears that SDA and SCL can be isolated simply by placing two unidirectional isolators in parallel, and in opposite directions. However, this technique creates feedback that latches the bus line low when a logic low asserted by either master or slave. This problem can be remedied by adding anti-latch circuits, but results in a larger and more expensive solution. The Si840x products offer a single-chip, anti-latch solution to the problem of isolating I2C/SMBus applications and require no external components except the I2C/SMBus pull-up resistors. In addition, they provide isolation to a maximum of 2.5 kVRMS, support I2C clock stretching, and operate to a maximum I2C bus speed of 1.7 Mbps. 4.2. I2C Isolator Operation Without anti-latch protection, bidirectional I2C isolators latch when an isolator output logic low propagates back through an adjacent isolator channel creating a stable latched low condition on both sides. Anti-latch protection is typically added to one side of the isolator to avoid this condition (the "A" side for the Si8400/01/02/05). The following examples illustrate typical circuit configurations using the Si8400/01/02/05. Si8400/01/02/05 I2C/SMBus Unit 1 + - VIL I2C/SMBus Unit 2 ISO1 V OL V IL V OL B Side A Side ISO2 Figure 15. Isolated Bus Overview (Bidirectional Channels) The "A side" output low (VOL) and input low (VIL) levels are designed such that the isolator VOL is greater than the isolator VIL to prevent the latch condition. 18 Rev. 1.4 Si840x 4.3. I2C Isolator Design Constraints Table 13 lists the design constraints. Table 13. Design Constraints Design Constraint To prevent the latch condition, the isolator output low level must be greater than the isolator input low level. The bus output low must be less than the isolator input low logic level. The isolator output low must be less than the bus input low. Data Sheet Values Effect of Bus Pull-up Strength and Temperature Isolator VOL 0.8 V typical Isolator VIL 0.6 V typical This is normally guaranteed by the isolator data sheet. However, if the pull up strength is too weak, the outInput/Output Logic Low Level put low voltage will fall and can get Difference too close to the input low logic level. VSDA1, VSCL1 = 50 mV minimum These track over temperature. Bus VOL = 0.4 V maximum Isolator VIL = 0.45 V minimum If the pull up strength is too large, the devices on the bus might not pull the voltage below the input low range. These have opposite temperature coefficients. Worst case is hot temperature. If the pull up strength is too large, the isolator might not pull below the Bus VIL 0.3 x VDD = 1.0 V minimum for bus input low voltage. VDD = 3.3 V Si8400/01/05 Vol: -1.8 mV/C CMOS buffer: -0.6 mV/C Isolator VOL = 0.825 V maximum, This provides some temperature (0.5 mA pullup, -10 to 125 C) tracking, but worst case is cold temperature. 4.4. I2C Isolator Design Considerations The first step in applying an I2C isolator is to choose which side of the bus will be connected to the isolator A side. Ideally, it should be the side which: 1. Is compatible with the range of bus pull up specified by the manufacturer. For example, the Si8400/01/02/05 isolators are normally used with a pull up of 0.5 mA to 3 mA. 2. Has the highest input low level for devices on the bus. Some devices may specify an input low of 0.9 V and other devices might require an input low of 0.3 x Vdd. Assuming a 3.3 V minimum power supply, the side with an input low of 0.3 x Vdd is the better side because this side has an input low level of 1.0 V. 3. Have devices on the bus that can pull down below the isolator input low level. For example, the Si840x input level is 0.45 V. As most CMOS devices can pull to within 0.4 V of GND this is generally not an issue. 4. Has the lowest noise. Due to the special logic levels, noise margins can be as low as 50 mV. The Si840x isolators are not compatible with devices that have a logic low of 0.8 V. For this situation, a discrete circuit can be used. See "AN352: Low-Cost, High-Speed I2C Isolation with Digital Isolators" for additional information. Rev. 1.4 19 Si840x Figures 16, 17, and 19 illustrate typical circuit configurations using the Si8400, Si8401, and Si8405. BVDD 8 1 AVDD 3k 3k 0.1 F 0.1 F ASDA 2 3k BSDA 7 ASCL 3 6 AGND 4 5 3k BSCL I2C Bus BGND Si8400 Figure 16. Typical Si8400 Application Diagram BVDD 8 1 AVDD 3k 3k 0.1 F 0.1 F ASDA 2 3k 7 ASCL 3 6 AGND 4 5 3k BSDA BSCL I2C Bus BGND Si8401 Figure 17. Typical Si8401 Application Diagram BVDD 3k ASDA 8 1 AVDD 0.1 F 0.1 F 2 3k 7 ASCL 3 6 AGND 4 5 Si8402 Figure 18. Typical Si8402 Application Diagram 20 Rev. 1.4 BSDA BSCL BGND I2C Bus Si840x BVDD AVDD 1 16 2 15 33 14 4 13 5 12 6 11 7 10 0.1 F 0.1 F 3k 3k ASDA RESET Microcontroller ASCL AGND 8 Si8405 3k 3k BSDA Microcontroller INT 9 I2C Bus BSCL BGND Figure 19. Typical Si8405 Application Diagram Rev. 1.4 21 Si840x 5. Errata and Design Migration Guidelines The following errata apply to Revision A devices only. See "7.Ordering Guide" on page 25 for more details. No errata exist for Revision B devices. 5.1. Power Supply Bypass Capacitors (Revision A and Revision B) When using the Si840x isolators with power supplies > 4.5 V, sufficient VDD bypass capacitors must be present on both the VDD1 and VDD2 pins to ensure the VDD rise time is less than 0.5 V/s (which is > 9 s for a > 4.5 V supply). Although rise time is power supply dependent, > 1 F capacitors are required on both power supply pins (VDD1, VDD2) of the isolator device. 5.1.1. Resolution For recommendations on resolving this issue, see "3.3.1.Supply Bypass" on page 14. Additionally, refer to "7.Ordering Guide" on page 25 for current ordering information. 22 Rev. 1.4 Si840x 6. Pin Descriptions AVDD 1 8 BVDD AVDD 1 8 BVDD ASDA 2 Bidirectional Isolator Channel 7 BSDA ASDA 2 Bidirectional Isolator Channel 7 BSDA ASCL 3 Bidirectional Isolator Channel 6 BSCL ASCL 3 Unidirectional Isolator Channel 6 BSCL 5 BGND AGND 4 AGND 4 Si8400 Si8401/02 5 BGND Table 14. Si8400/01/02 in SO-8 Package Pin Name Description 1 AVDD Side A power supply terminal; connect to a source of 3.0 to 5.5 V. 2 ASDA Side A data (open drain) input or output. 3 ASCL Side A clock input or output. Open drain I/O for Si8400/01. Standard CMOS input for Si8402. 4 AGND Side A ground terminal. 5 BGND Side B ground terminal. 6 BSCL Side B clock input or output. Open drain I/O for Si8400/01. Push-pull output for Si8402. 7 BSDA Side B data (open drain) input or output. 8 BVDD Side B power supply terminal; connect to a source of 3.0 to 5.5 V. Rev. 1.4 23 Si840x 16 BVDD AVDD 1 NC 2 ASDA 3 ADIN 4 ADOUT 5 ASCL 6 15 NC Bidirectional Isolator Channel Unidirectional Isolator Channel Unidirectional Isolator Channel Bidirectional Isolator Channel NC 7 AGND 8 14 BSDA 13 BDOUT 12 BDIN 11 BSCL 10 NC Si8405 9 BGND Table 15. Si8405 in Narrow-Body SO-16 Package 24 Pin Name Description 1 AVDD 2 NC 3 ASDA Side A Data (open drain) Input or Output. 4 ADIN Side A Standard CMOS Digital Input (non I2C). 5 ADOUT Side A Digital Push-Pull Output (non I2C). 6 ASCL Side A Clock (open drain) Input or Output. 7 NC 8 AGND Side A Ground Terminal. 9 BGND Side B Ground Terminal. 10 NC 11 BSCL Side B Clock (open drain) Input or Output. 12 BDIN Side B Standard CMOS Digital Input (non I2C). 13 BDOUT Side B Digital Push-Pull Output (non I2C). 14 BSDA Side B Data (open drain) Input or Output. 15 NC 16 BVDD Side A Power Supply Terminal. Connect to a source of 3.0 to 5.5 V. No connection. No connection. No connection. No connection. Side B Power Supply Terminal. Connect to a source of 3.0 to 5.5 V. Rev. 1.4 Si840x 7. Ordering Guide Revision B devices are recommended for all new designs. Table 16. Ordering Guide1 Ordering Part Number Number of Bidirection al I2C Channels Max I2C Bus Speed (MHz) Number of Unidirectional Channels Max Data Rate of Non-I2C Unidirectional Channels (Mbps) Isolation Ratings Temp Range (C) Package Revision B Devices2 Si8400AA-B-IS 2 1.7 0 -- 1 kVRMS -40 to 125 NB SOIC-8 Si8400AB-B-IS 2 1.7 0 -- 2.5 kVRMS -40 to 125 NB SOIC-8 Si8401AA-B-IS 1 1.7 1 -- 1 kVRMS -40 to 125 NB SOIC-8 Si8401AB-B-IS 1 1.7 1 -- 2.5 kVRMS -40 to 125 NB SOIC-8 Si8402AB-B-IS 1 1.7 1 10 2.5 kVRMS -40 to 125 NB SOIC-8 Si8405AA-B-IS1 2 1.7 1 forward 1 reverse 10 1 kVRMS -40 to 125 NB SOIC-16 Si8405AB-B-IS1 2 1.7 1 forward 1 reverse 10 2.5 kVRMS -40 to 125 NB SOIC-16 Si8400AA-A-IS 2 1.7 0 -- 1 kVRMS -40 to 125 NB SOIC-8 Si8400AB-A-IS 2 1.7 0 -- 2.5 kVRMS -40 to 125 NB SOIC-8 Si8405AA-A-IS1 2 1.7 1 forward 1 reverse 10 1 kVRMS -40 to 125 NB SOIC-16 Si8405AB-A-IS1 2 1.7 1 forward 1 reverse 10 2.5 kVRMS -40 to 125 NB SOIC-16 Revision A Devices2 Notes: 1. All packages are RoHS-compliant. Moisture sensitivity level is MSL2A with peak reflow temperature of 260 C according to the JEDEC industry standard classifications and peak solder temperature. 2. Revision A devices are supported for existing designs, but Revision B is recommended for all new designs. Rev. 1.4 25 Si840x 8. Package Outline: 8-Pin Narrow Body SOIC Figure 20 illustrates the package details for the Si840x in an 8-pin SOIC (SO-8). Table 17 lists the values for the dimensions shown in the illustration. Figure 20. 8-pin Small Outline Integrated Circuit (SOIC) Package Table 17. Package Diagram Dimensions Symbol Millimeters Min Max A 1.35 1.75 A1 0.10 0.25 A2 1.40 REF 1.55 REF B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 e 26 1.27 BSC H 5.80 6.20 h 0.25 0.50 L 0.40 1.27 0 8 Rev. 1.4 Si840x 9. Land Pattern: 8-Pin Narrow Body SOIC Figure 21 illustrates the recommended land pattern details for the Si840x in an 8-pin narrow-body SOIC. Table 18 lists the values for the dimensions shown in the illustration. Figure 21. PCB Land Pattern: 8-Pin Narrow Body SOIC Table 18. PCM Land Pattern Dimensions (8-Pin Narrow Body SOIC) Dimension Feature (mm) C1 Pad Column Spacing 5.40 E Pad Row Pitch 1.27 X1 Pad Width 0.60 Y1 Pad Length 1.55 Notes: 1. This Land Pattern Design is based on IPC-7351 pattern SOIC127P600X173-8N for Density Level B (Median Land Protrusion). 2. All feature sizes shown are at Maximum Material Condition (MMC) and a card fabrication tolerance of 0.05 mm is assumed. Rev. 1.4 27 Si840x 10. Package Outline: 16-Pin Narrow Body SOIC Figure 22 illustrates the package details for the Si840x in a 16-pin narrow-body SOIC (SO-16). Table 19 lists the values for the dimensions shown in the illustration. Figure 22. 16-pin Small Outline Integrated Circuit (SOIC) Package Table 19. Package Diagram Dimensions Dimension Min Max A -- 1.75 A1 0.10 0.25 A2 1.25 -- b 0.31 0.51 c 0.17 0.25 D 9.90 BSC E 6.00 BSC E1 3.90 BSC e 1.27 BSC L 0.40 L2 28 1.27 0.25 BSC Rev. 1.4 Si840x Table 19. Package Diagram Dimensions (Continued) Dimension Min Max h 0.25 0.50 0 8 aaa 0.10 bbb 0.20 ccc 0.10 ddd 0.25 Notes: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing per ANSI Y14.5M-1994. 3. This drawing conforms to the JEDEC Solid State Outline MS-012, Variation AC. 4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components. Rev. 1.4 29 Si840x 11. Land Pattern: 16-Pin Narrow Body SOIC Figure 23 illustrates the recommended land pattern details for the Si840x in a 16-pin narrow-body SOIC. Table 20 lists the values for the dimensions shown in the illustration. Figure 23. 16-Pin Narrow Body SOIC PCB Land Pattern Table 20. 16-Pin Narrow Body SOIC Land Pattern Dimensions Dimension Feature (mm) C1 Pad Column Spacing 5.40 E Pad Row Pitch 1.27 X1 Pad Width 0.60 Y1 Pad Length 1.55 Notes: 1. This Land Pattern Design is based on IPC-7351 pattern SOIC127P600X165-16N for Density Level B (Median Land Protrusion). 2. All feature sizes shown are at Maximum Material Condition (MMC) and a card fabrication tolerance of 0.05 mm is assumed. 30 Rev. 1.4 Si840x 12. Top Marking: 8-Pin Narrow Body SOIC 12.1. 8-Pin Narrow Body SOIC Top Marking Si84XYSV YYWWRF e3 AIXX 12.2. Top Marking Explanation Line 1 Marking: Si84 = Isolator I2C Product Series: XY = Channel Configuration Base Part Number Ordering Options 00 (See Ordering Guide for more information). S = Speed Grade A Line 3 Marking: = 1.7 Mbps V = Isolation rating A Line 2 Marking: = Bidirectional SCL and SDA channels = Bidirectional SDA channel; Unidirectional SCL channel 01/02 = 1 kV; B = 2.5 kV YY = Year WW = Work week Assigned by assembly contractor. Corresponds to the year and work week of the mold date. R = Product Rev F = Wafer Fab First two characters of the manufacturing code from Assembly. Circle = 1.1 mm Diameter Left-Justified "e3" Pb-Free Symbol A = Assembly Site I = Internal Code XX = Serial Lot Number Last four characters of the manufacturing code from assembly. Rev. 1.4 31 Si840x 13. Top Marking: 16-Pin Narrow Body SOIC 13.1. 16-Pin Narrow Body SOIC Top Marking e3 Si84XYSV YYWWTTTTTT 13.2. Top Marking Explanation Line 1 Marking: Base Part Number Ordering Options Si84 = Isolator product series XY = Channel Configuration 05 = Bidirectional SCL, SDA; 1- forward and 1-reverse unidirectional channel S = Speed Grade A A Line 2 Marking: 32 = 1.7 Mbps V = Isolation rating = 1 kV; B = 2.5 kV Circle = 1.2 mm Diameter "e3" Pb-Free Symbol YY = Year WW = Work Week Assigned by the Assembly House. Corresponds to the year and work week of the mold date. TTTTTT = Mfg code Manufacturing Code from Assembly Purchase Order form. Circle = 1.2 mm diameter "e3" Pb-Free Symbol. Rev. 1.4 Si840x DOCUMENT CHANGE LIST Revision 1.3 to Revision 1.4 Revision 0.1 to Revision 1.0 Updated document to reflect availability of Revision B silicon. Updated Tables 2, 3, 4, and 5. Updated all supply currents and timing parameters. Revised logic low output voltage specifications in Table 3. Updated Table 1. Updated absolute maximum supply voltage. Updated Table 7. Updated Updated "3.3.1.Supply Bypass" on page 14. Added Figure 8, "Recommended Bypass Components for the Si84xx Digital Isolator Family," on page 14. Updated "5.1.Power Supply Bypass Capacitors (Revision A and Revision B)" on page 22. clearance and creepage dimensions. Updated "5.Errata and Design Migration Guidelines" on page 22. Updated "7.Ordering Guide" on page 25. Revision 1.0 to Revision 1.1 Updated Table 4. Updated Updated Note 1 to reflect output impedance of 85 . rise and fall time specifications. Updated Table 5. Updated CMTI value. Updated "7. Ordering Guide". Added Si8401 device configuration throughout document. Revision 1.1 to Revision 1.2 Updated document throughout to include MSL improvements to MSL2A. Updated "7.Ordering Guide" on page 25. Updated Note 1 in ordering guide table to reflect improvement and compliance to MSL2A moisture sensitivity level. Revision 1.2 to Revision 1.3 Added Si8402 throughout document. Clarified description of Si8401's BSCL pin to indicate pin type is an open output, whereas the Si8402's BSCL pin is a push-pull CMOS pin. Updated "7.Ordering Guide" on page 25 to include Si8402. Moved Table 1 to page 4. Updated Tables 6, 7, 8, and 9. Updated Table 12 footnotes. Added Figure 14, "Si84xx Time-Dependent Dielectric Breakdown," on page 17. Added Figure 18, "Typical Si8402 Application Diagram," on page 20. Rev. 1.4 33 Si840x CONTACT INFORMATION Silicon Laboratories Inc. 400 West Cesar Chavez Austin, TX 78701 Tel: 1+(512) 416-8500 Fax: 1+(512) 416-9669 Toll Free: 1+(877) 444-3032 Please visit the Silicon Labs Technical Support web page: https://www.silabs.com/support/pages/contacttechnicalsupport.aspx and register to submit a technical support request. The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice. Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features or parameters. Silicon Laboratories reserves the right to make changes without further notice. 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Other products or brandnames mentioned herein are trademarks or registered trademarks of their respective holders. 34 Rev. 1.4