High Stability Isolated Error Amplifier ADuM3190 Data Sheet FEATURES GENERAL DESCRIPTION Stable over time and temperature 0.5% initial accuracy 1% accuracy over the full temperature range Compatible with Type II or Type III compensation networks Reference voltage: 1.225 V Compatible with DOSA Low power operation: <7 mA total Wide voltage supply range VDD1: 3 V to 20 V VDD2: 3 V to 20 V Bandwidth: 400 kHz Isolation voltage: 2.5 kV rms Safety and regulatory approvals (pending) UL recognition: 2500 V rms for 1 minute per UL 1577 CSA Component Acceptance Notice #5A VDE certificate of conformity DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 VIORM = 560 V peak Wide temperature range −40°C to +125°C ambient operation 150°C maximum junction temperature The ADuM31901 is an isolated error amplifier based on Analog Devices, Inc., iCoupler® technology. The ADuM3190 is ideal for linear feedback power supplies. The primary side controllers of the ADuM3190 enable improvements in transient response, power density, and stability as compared to commonly used optocoupler and shunt regulator solutions. Unlike optocoupler-based solutions, which have an uncertain current transfer ratio over lifetime and at high temperatures, the ADuM3190 transfer function does not change over its lifetime and it is stable over a wide temperature range of −40°C to +125°C. Included in the ADuM3190 is a wideband operational amplifier for a variety of commonly used power supply loop compensation techniques. The ADuM3190 is fast enough to allow a feedback loop to react to fast transient conditions and overcurrent conditions. Also included is a high accuracy 1.225 V reference to compare with the supply output setpoint. The ADuM3190 is packaged in a small 16-lead QSOP package for a 2.5 kV rms isolation voltage rating. APPLICATIONS Linear power supplies Inverters Uninterruptible Power Supply (UPS) DOSA-compatible modules Voltage monitors VDD1 1 16 VDD2 GND1 2 15 GND2 VREG1 3 14 VREG2 13 REFOUT 12 +IN REFOUT1 4 REG UVLO UVLO REF REF NC 5 EAOUT2 6 EAOUT 7 REG Tx Rx GND1 8 11 –IN 10 COMP 9 GND2 11335-001 FUNCTIONAL BLOCK DIAGRAM Figure 1. 1 Protected by U.S. Patents 5,952,849, 6,873,065 and 7,075,329. Other patents pending. Rev. 0 Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 ©2013 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com ADuM3190 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Pin Configuration and Function Descriptions..............................7 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................8 General Description ......................................................................... 1 Test Circuits ..................................................................................... 11 Functional Block Diagram .............................................................. 1 Applications Information .............................................................. 12 Revision History ............................................................................... 2 Theory of Operation .................................................................. 12 Specifications..................................................................................... 3 Accuracy Circuit Operation...................................................... 12 Package Characteristics ............................................................... 4 Application Block Diagram ...................................................... 12 Regulatory Information ............................................................... 4 Setting the Output Voltage ........................................................ 13 Insulation and Safety Related Specifications ............................ 4 DOSA Module Application....................................................... 14 Recommended Operating Conditions ...................................... 4 DC Correctness and Magnetic Field Immunity .......................... 14 DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Characteristics .............................................................................. 5 Insulation Lifetime ..................................................................... 15 Packaging and Ordering Information ......................................... 16 Absolute Maximum Ratings ....................................................... 6 Outline Dimensions ................................................................... 16 ESD Caution .................................................................................. 6 Ordering Guide .......................................................................... 16 REVISION HISTORY 2/13—Revision 0: Initial Version Rev. 0 | Page 2 of 16 Data Sheet ADuM3190 SPECIFICATIONS VDD1 = VDD2 = 3 V to 20 V for TA = TMIN to TMAX. All typical specifications are at TA = 25°C and VDD1 = VDD2 = 5 V, unless otherwise noted. Table 1. Parameter ACCURACY Initial Error Total Error OP AMP Offset Error Open-Loop Gain Input Common-Mode Range Gain Bandwidth Product Common-Mode Rejection Input Capacitance Output Voltage Range Input Bias Current REFERENCE Output Voltage Output Current UVLO Positive Going Threshold Negative Going Threshold EAOUT Impedance OUTPUT CHARACTERISTICS Output Gain Output −3 dB Bandwidth A and S Grades B and T Grades Output Voltage EAOUT Low High EAOUT2 Low High Low High Noise EAOUT EAOUT2 POWER SUPPLY Operating Range, Side 1 Operating Range, Side 2 Power Supply Rejection Supply Current IDD1 IDD2 Test Conditions/Comments (1.225 V − EAOUT)/1.225 V × 100%; see Figure 18 TA = 25°C TA = TMIN to TMAX Min −5 66 0.35 Typ Max Unit 0.25 0.5 0.5 1 % % ±2.5 80 +5 mV dB V MHz dB pF V μA 1.5 10 72 2 COMP pin 0.2 2.7 0.01 At 25°C, 0 mA to 1 mA load, CREFOUT = 15 pF −40°C to +125°C, 0 mA to 1 mA load, CREFOUT = 15 pF CREFOUT = 15 pF 1.215 1.213 2.0 1.225 1.225 1.235 1.237 V V mA 2.8 2.6 High-Z 2.96 2.4 V V Ω 0.9 1.0 1.1 V/V 2.34 2.6 2.86 V/V 100 250 200 400 2.4 2.5 VDD2 < UVLO threshold or VDD1 < UVLO threshold From COMP to EAOUT, dc, 0.3 V to 2.4 V; and from COMP to EAOUT2, dc, 0.4 V to 5.0 V From COMP to EAOUT, 0.3 V to 2.4 V, ±3 mA; and from COMP to EAOUT2, 0.4 V to 5.0 V, ±1 mA kHz kHz ±3 mA output ±1 mA output VDD1 = 4.5 V to 5.5 V VDD1 = 4.5 V to 5.5 V VDD1 = 10 V to 20 V VDD1 = 10 V to 20 V See Figure 18 4.8 5.0 0.3 4.9 0.3 5.4 0.4 V V 0.6 V V V V 0.6 1.7 4.8 VDD1 VDD2 DC, VDD1 = VDD2 = 3 V to 20 V See Figure 18 See Figure 18 3.0 3.0 60 1.4 2.9 Rev. 0 | Page 3 of 16 mV rms mV rms 20 20 V V dB 2.0 5.0 mA mA ADuM3190 Data Sheet PACKAGE CHARACTERISTICS Table 2. Parameter RESISTANCE Input-to-Output 1 CAPACITANCE Input-to-Output1 Input Capacitance 2 IC JUNCTION-TO-AMBIENT THERMAL RESISTANCE 16-Lead QSOP 1 2 Symbol Min Typ Max Unit RI-O 1013 Ω CI-O CI 2.2 4.0 pF pF Test Conditions/Comments f = 1 MHz Thermocouple located at center of package underside θJA 76 °C/W The device is considered a 2-terminal device; Pin 1 through Pin 8 are shorted together, and Pin 9 through Pin 16 are shorted together. Input capacitance is from any input data pin to ground. REGULATORY INFORMATION The ADuM3190 is pending approval by the organizations listed in Table 3. See Table 8 and the Insulation Lifetime section for recommended maximum working voltages for specific cross-isolation waveforms and insulation levels. Table 3. UL (Pending) Recognized Under 1577 Component Recognition Program 1 Single Protection, 2500 V rms Isolation Voltage, 16-Lead QSOP File E214400 1 2 CSA (Pending) Approved under CSA Component Acceptance Notice #5A Basic insulation per CSA 60950-1-03 and IEC 60950-1, 400 V rms (565 V peak) maximum working voltage File 205078 VDE (Pending) Certified according to DIN V VDE V 0884-10 (VDE V 0884-10): 2006-12 2 Reinforced insulation, 560 V peak File 2471900-4880-0001 In accordance with UL 1577, each ADuM3190 is proof tested by applying an insulation test voltage ≥ 3000 V rms for 1 sec (current leakage detection limit = 5 µA). In accordance with DIN V VDE V 0884-10, each ADuM3190 is proof tested by applying an insulation test voltage ≥ 1050 V peak for 1 sec (partial discharge detection limit = 5 pC). The asterisk (*) marked on the component designates DIN V VDE V 0884-10 approval. INSULATION AND SAFETY RELATED SPECIFICATIONS Table 4. Parameter Rated Dielectric Insulation Voltage Minimum External Air Gap (Clearance) Symbol L(I01) Value 2500 3.8 min Unit V rms mm Minimum External Tracking (Creepage) L(I02) 3.1 min mm Minimum Internal Gap (Internal Clearance) Tracking Resistance (Comparative Tracking Index) Isolation Group CTI 0.017 min >400 II mm V Test Conditions/Comments 1-minute duration Measured from input terminals to output terminals, shortest distance through air Measured from input terminals to output terminals, shortest distance path along body Insulation distance through insulation DIN IEC 112/VDE 0303, Part 1 Material Group DIN VDE 0110, 1/89, Table 1 RECOMMENDED OPERATING CONDITIONS Table 5. Parameter OPERATING TEMPERATURE BY MODEL ADuM3190A/ADuM3190B ADuM3190S/ADuM3190T SUPPLY VOLTAGES 1 INPUT SIGNAL RISE AND FALL TIMES 1 Symbol TA VDD1, VDD2 tR, tF All voltages are relative to their respective grounds. Rev. 0 | Page 4 of 16 Min Max Unit −40 −40 3.0 +85 +125 20 1.0 °C °C V ms Data Sheet ADuM3190 DIN V VDE V 0884-10 (VDE V 0884-10) INSULATION CHARACTERISTICS These isolators are suitable for reinforced isolation only within the safety limit data. Maintenance of the safety data is ensured by protective circuits. The asterisk (*) marking branded on the package denotes DIN V VDE V 0884-10 approval for a 560 V peak working voltage. Table 6. Description Installation Classification per DIN VDE 0110 For Rated Mains Voltage ≤ 150 V rms For Rated Mains Voltage ≤ 300 V rms For Rated Mains Voltage ≤ 400 V rms Climatic Classification Pollution Degree per DIN VDE 0110, Table 1 Maximum Working Insulation Voltage Input-to-Output Test Voltage, Method B1 Test Conditions/Comments Symbol VIORM × 1.875 = Vpd(m), 100% production test, tini = tm = 1 sec, partial discharge < 5 pC Input-to-Output Test Voltage, Method A After Environmental Tests Subgroup 1 VIORM × 1.5 = Vpd(m), tini = 60 sec, tm = 10 sec, partial discharge < 5 pC VIORM × 1.2 = Vpd(m), tini = 60 sec, tm = 10 sec, partial discharge < 5 pC After Input and/or Safety Test Subgroup 2 and Subgroup 3 Highest Allowable Overvoltage Surge Isolation Voltage Safety Limiting Values VPEAK = 10 kV; 1.2 µs rise time; 50 µs, 50% fall time Maximum value allowed in the event of a failure (see Figure 2) Case Temperature Safety Total Dissipated Power Insulation Resistance at TS VIO = 500 V VIORM Vpd(m) V peak V peak Vpd(m) 840 V peak Vpd(m) 672 V peak VIOTM VIOSM 3500 4000 V peak V peak TS PS RS 150 1.64 >109 °C W Ω SAFE LIMITING POWER (W) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 50 100 150 AMBIENT TEMPERATURE (°C) 200 11335-004 0.2 0 Figure 2. Thermal Derating Curve, Dependence of Safety Limiting Values on Case Temperature, per DIN V VDE V 0884-10 Rev. 0 | Page 5 of 16 Unit I to IV I to III I to II 40/105/21 2 560 1050 1.8 0 Characteristic ADuM3190 Data Sheet ABSOLUTE MAXIMUM RATINGS Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. TA = 25°C, unless otherwise noted. Table 7. Parameter Storage Temperature (TST) Range Ambient Operating Temperature (TA) Range Junction Temperature Supply Voltages VDD1, VDD21 VREG1, VREG21 Input Voltages (+IN, −IN) Output Voltages REFOUT, COMP, REFOUT1, EAOUT EAOUT2 Output Current per Output Pin Common-Mode Transients2 1 2 Rating −65°C to +150°C −40°C to +125°C −40°C to +150°C Table 8. Maximum Continuous Working Voltage1 −0.5 V to +24 V −0.5 V to +3.6 V −0.5 V to +3.6 V −0.5 V to +3.6 V −0.5 V to +5.5 V −11 mA to +11 mA −100 kV/μs to +100 kV/μs All voltages are relative to their respective grounds. Refers to common-mode transients across the insulation barrier. Commonmode transients exceeding the absolute maximum ratings may cause latch-up or permanent damage. Parameter WAVEFORM AC Voltage Bipolar Unipolar DC Voltage 1 Max Unit Constraint 560 1131 1131 V peak V peak V peak 50-year minimum lifetime 50-year minimum lifetime 50-year minimum lifetime Refers to continuous voltage magnitude imposed across the isolation barrier. See the Insulation Lifetime section for more details. ESD CAUTION Rev. 0 | Page 6 of 16 Data Sheet ADuM3190 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 1 16 VDD2 2 15 GND2 14 VREG2 VREG1 3 REFOUT1 4 NC 5 EAOUT2 6 11 –IN EAOUT 7 10 COMP GND1 8 ADuM3190 TOP VIEW (Not to Scale) 13 REFOUT 12 +IN 9 GND2 NC = NO CONNECTION. CONNECT PIN 5 TO GND1; DO NOT LEAVE THIS PIN FLOATING. 11335-005 VDD1 Figure 3. Pin Configuration Table 9. Pin Function Descriptions Pin No. 1 2 3 4 5 6 Mnemonic VDD1 GND1 VREG1 REFOUT1 NC EAOUT2 7 8 9 10 11 12 13 14 15 16 EAOUT GND1 GND2 COMP −IN +IN REFOUT VREG2 GND2 VDD2 Description Supply Voltage for Side 1 (3.0 V to 20 V). Connect a 1 μF capacitor between VDD1 and GND1. Ground Reference for Side 1. Internal Supply Voltage for Side 1. Connect a 1 μF capacitor between VREG1 and GND1. Reference Output Voltage for Side 1. The maximum capacitance for this pin (CREFOUT1) must not exceed 15 pF. No Connection. Connect Pin 5 to GND1; do not leave this pin floating. Isolated Output Voltage 2, Open-Drain Output. Connect a pull-up resistor between EAOUT2 and VDD1 for current up to 1 mA. Isolated Output Voltage. Ground Reference for Side 1. Ground Reference for Side 2. Output of the Op Amp. A loop compensation network can be connected between the COMP pin and the −IN pin. Inverting Op Amp Input. Pin 11 is the connection for the power supply setpoint and compensation network. Noninverting Op Amp Input. Pin 12 can be used as a reference input. Reference Output Voltage for Side 2. The maximum capacitance for this pin (CREFOUT) must not exceed 15 pF. Internal Supply Voltage for Side 2. Connect a 1 μF capacitor between VREG2 and GND2. Ground Reference for Side 2. Supply Voltage for Side 2 (3.0 V to 20 V). Connect a 1 μF capacitor between VDD2 and GND2. Rev. 0 | Page 7 of 16 ADuM3190 Data Sheet TYPICAL PERFORMANCE CHARACTERISTICS 3 1.228 VDDx = 20V VDDx = 5V REFOUT ACCURACY (V) 1.227 2 IDD1 (mA) 1.226 1.225 1 1.224 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 1.222 –40 11335-017 0 –40 EAOUT ACCURACY (%) 60 80 100 120 140 3 2 0.5 0 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) –1.0 –40 11335-018 0 –40 10 2 OP AMP OFFSET VOLTAGE (mV) 3 8 6 4 40 60 80 100 120 TEMPERATURE (°C) 140 40 60 80 100 120 140 120 140 1 0 –1 –2 –3 –40 11335-019 2 20 20 Figure 8. EAOUT Accuracy vs. Temperature 12 0 0 TEMPERATURE (°C) Figure 5. Typical IDD2 Supply Current vs. Temperature –20 –20 11335-021 –0.5 11335-022 IDD2 (mA) 40 1.0 VDDx = 20V VDDx = 5V 1 INPUT BIAS CURRENT (nA) 20 Figure 7. REFOUT Accuracy vs. Temperature 4 0 –40 0 TEMPERATURE (°C) Figure 4. Typical IDD1 Supply Current vs. Temperature 5 –20 11335-020 1.223 –20 0 20 40 60 80 100 TEMPERATURE (°C) Figure 9. Op Amp Offset Voltage vs. Temperature Figure 6. +IN, −IN Input Bias Current vs. Temperature Rev. 0 | Page 8 of 16 ADuM3190 0 90 –20 EAOUT OFFSET (mV) 100 80 70 –40 –60 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) –100 –40 20 40 60 80 100 120 140 120 140 Figure 13. EAOUT Offset vs. Temperature 1.05 0 –50 EAOUT2 OFFSET (mV) 1.04 EAOUT GAIN (V/V) 0 TEMPERATURE (°C) Figure 10. Op Amp Open-Loop Gain vs. Temperature 1.03 1.02 1.01 –100 –150 –200 –250 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) –300 –40 11335-024 1.00 –40 –20 11335-026 50 –40 11335-027 –80 60 11335-023 OP AMP OPEN-LOOP GAIN (dB) Data Sheet –20 0 20 40 60 80 100 TEMPERATURE (°C) Figure 11. EAOUT Gain vs. Temperature Figure 14. EAOUT2 Offset vs. Temperature 2.70 2.68 2.66 2.64 2 2.60 –40 –20 0 20 40 60 80 100 TEMPERATURE (°C) Figure 12. EAOUT2 Gain vs. Temperature 120 140 CH1 10mV Ω CH2 10mV Ω M4.0µs A CH1 T 102.4ns 1.18V 11335-028 2.62 11335-025 EAOUT2 GAIN (V/V) 1 Figure 15. Output Noise with Test Circuit 1, Channel 1 = EAOUT (10 mV/div), Channel 2 = EAOUT2 (10 mV/div) Rev. 0 | Page 9 of 16 ADuM3190 Data Sheet 2 1 1 3 CH1 100mV Ω CH2 100mV Ω CH3 200mV Ω M2µs T 0s A CH1 434mV CH1 20mV Ω CH3 20mV Ω Figure 16. Output 100 kHz Signal with Test Circuit 3, Channel 1 = +IN, Channel 2 = EAOUT, Channel 3 = EAOUT2 Rev. 0 | Page 10 of 16 CH2 50mV Ω M2µs A CH1 T 5.92µs 399mV Figure 17. Output Square Wave Response with Test Circuit 3, Channel 1 = +IN, Channel 2 = EAOUT, Channel 3 = EAOUT2 11335-030 3 11335-029 2 Data Sheet ADuM3190 TEST CIRCUITS VDD1 1µF GND1 1µF VREG1 1 16 2 15 REG 3 REFOUT1 4 UVLO UVLO REF REF NC 5 GND2 1µF VREG2 1µF REFOUT 13 12 Tx EAOUT2 6 EAOUT 11 Rx 7 10 8 9 +IN –IN 680Ω COMP 2.2nF GND2 11335-002 GND1 14 REG VDD2 Figure 18. Test Circuit 1 VDD1 1µF GND1 1µF VREG1 1 16 2 15 REG 3 REFOUT1 4 ROD UVLO REF 6 11 Rx 1µF VREG2 1µF REFOUT 13 12 Tx GND2 7 10 8 9 +IN –IN 680Ω COMP 2.2nF GND2 11335-003 GND1 14 REG REF NC 5 EAOUT2 EAOUT UVLO VDD2 Figure 19. Test Circuit 2 GND1 1µF VREG1 ROD 1 16 2 15 REG 3 REFOUT1 4 UVLO EAOUT GND1 6 14 REG REF REF NC 5 EAOUT2 UVLO Tx Rx 13 12 11 7 10 8 9 Figure 20. Test Circuit 3 Rev. 0 | Page 11 of 16 VDD2 GND2 1µF VREG2 1µF REFOUT +IN –IN COMP GND2 11335-031 VDD1 1µF ADuM3190 Data Sheet APPLICATIONS INFORMATION In the test circuits of the ADuM3190 (see Figure 18 through Figure 20), external supply voltages from 3 V to 20 V are provided to the VDD1 and VDD2 pins, and internal regulators provide 3.0 V to operate the internal circuits of each side of the ADuM3190. An internal precision 1.225 V reference provides the reference for the ±1% accuracy of the isolated error amplifier. UVLO circuits monitor the VDDx supplies to turn on the internal circuits when the 2.8 V rising threshold is met and to turn off the error amplifier outputs to a high impedance state when VDDx falls below 2.6 V. approximately 100 kHz, but the circuit is more stable with a phase shift of approximately −120°, which yields a stable 60° phase margin. This circuit is used for accuracy tests only, not for real-world applications, because it has a 680 Ω resistor across the isolation barrier to close the loop for the error amplifier; this resistor causes leakage current to flow across the isolation barrier. For this test circuit only, GND1 must be connected to GND2 to create a return for the leakage current created by the 680 Ω resistor connection. AMPLITUDE (dB) The op amp on the right side of the device has a noninverting +IN pin and an inverting −IN pin available for connecting a feedback voltage in an isolated dc-to-dc converter output, usually through a voltage divider. The COMP pin is the op amp output, which can be used to attach resistor and capacitor components in a compensation network. The COMP pin internally drives the Tx transmitter block, which converts the op amp output voltage into an encoded output that is used to drive the digital isolator transformer. 100 OP AMP AND LINEAR ISOLATOR OP AMP ALONE LINEAR ISOLATOR POLE AT 400kHz 100 1k 10k 1M 10M FREQUENCY (Hz) LINEAR ISOLATOR PHASE (°) 100 100k 1k 10k 100k 1M 10M FREQUENCY (Hz) –90 On the left side of the ADuM3190, the transformer output PWM signal is decoded by the Rx block, which converts the signal into a voltage that drives an amplifier block; the amplifier block produces the error amplifier output available at the EAOUT pin. The EAOUT pin can deliver ±3 mA and has a voltage level between 0.4 V and 2.4 V, which is typically used to drive the input of a PWM controller in a dc-to-dc circuit. –180 11335-006 THEORY OF OPERATION Figure 21. Bode Plot 1 AMPLITUDE (dB) OP AMP AND LINEAR ISOLATOR 100 For applications that need more output voltage to drive their controllers, Figure 19 illustrates the use of the EAOUT2 pin output which delivers up to ±1 mA with an output voltage of 0.6 V to 4.8 V for an output that has a pull-up resistor to a 5 V supply. If the EAOUT2 pull-up resistor connects to a 10 V to 20 V supply, the output is specified to a minimum of 5.0 V to allow use with a PWM controller requiring a minimum input operation of 5 V. LINEAR ISOLATOR POLE AT 400kHz 1k 10k 100k 1M OP AMP ALONE FREQUENCY (Hz) 10M 1k 10k 100k 1M 10M INTEGRATOR CONFIGURATION 100 PHASE (°) 100 FREQUENCY (Hz) –90 ACCURACY CIRCUIT OPERATION See Figure 18 and Figure 19 for stability of the accuracy circuits. The op amp on the right side of the ADuM3190, from the −IN pin to the COMP pin, has a unity-gain bandwidth (UGBW) of 10 MHz. Figure 21, Bode Plot 1, shows a dashed line for the op amp alone and its 10 MHz pole. Figure 21 also shows the linear isolator alone (the blocks from the op amp output to the ADuM3190 output, labeled as the linear isolator), which introduces a pole at approximately 400 kHz. This total Bode plot of the op amp and linear isolator shows that the phase shift is approximately −180° from the −IN pin to the EAOUT pin before the crossover frequency. Because a −180° phase shift can make the system unstable, adding an integrator configuration, as shown in the test circuits in Figure 18 and Figure 19, consisting of a 2.2 nF capacitor and a 680 Ω resistor, helps to make the system stable. In Figure 22, Bode Plot 2 with an integrator configuration added, the system crosses over 0 dB at 11335-007 –180 Figure 22. Bode Plot 2 APPLICATION BLOCK DIAGRAM Figure 23 shows a typical application, an isolated error amplifier in primary side control, for the ADuM3190. The op amp of the ADuM3190 is used as the error amplifier for the feedback of the output voltage, VOUT, using a resistor divider to the −IN pin of the op amp. This configuration inverts the output signal at the COMP pin when compared to the +IN pin, which is connected to the internal 1.225 V reference. For example, when the output voltage, VOUT, falls due to a load step, the divider voltage at the −IN pin falls below the +IN reference voltage, causing the COMP pin output signal to go high. The COMP output of the op amp is encoded and then decoded back by the digital isolator transformer block to a signal that drives the output of the ADuM3190 Rev. 0 | Page 12 of 16 Data Sheet ADuM3190 high. The output of the ADuM3190 drives the COMP pin of the PWM controller, which is designed to reset the PWM latch output to low only when its COMP pin is low. A high at the COMP pin has the effect of making the latching PWM comparator produce a PWM duty cycle output. This PWM duty cycle output drives the power stage to increase the VOUT voltage until it returns to regulation. EAOUT2 output is used for a PWM controller with a 2.5 V reference. PWM CONTROLLER VREF FB PWM CONTROLLER EAOUT2 POWER STAGE CO CURRENT SENSE COMP C2 ESR COMP OP AMP ADuM3190 R2 –IN 1.225V REFOUT Figure 24. Application Block Diagram 2 –IN +IN REFOUT + +IN C1 COMPENSATION NETWORK 1.225V CO COMPENSATION NETWORK ESR OP AMP ADuM3190 + R2 VOUT DCR CURRENT SENSE C2 EAOUT2 VOUT DCR POWER STAGE 11335-009 FB COMP LATCHING PWM LO LO LATCHING PWM COMP VIN OSC ERROR AMP ERROR AMP C1 11335-008 VREF VIN OSC Figure 23. Application Block Diagram 1 The power stage output is filtered by output capacitance and, in some applications, by an inductor. Various elements contribute to the gain and phase of the control loop and the resulting stability. The Output Filter L and Output Filter C components create a double pole; the op amp has a pole at 10 MHz (see Figure 21), and the linear isolator has a pole at 400 kHz (see Figure 21 and Figure 22). The output capacitor and its ESR can add a zero at a frequency that is dependent on the component type and values. With the ADuM3190 providing the error amplifier, a compensation network is provided from the −IN pin to the COMP pin to compensate the control loop for stability. The compensation network values depend on both the application and the components that are selected; information about the component network values is provided in the data sheet of the selected PWM controller. The ADuM3190 has two different error amplifier outputs, EAOUT and EAOUT2. The EAOUT output, which can drive ±3 mA, has a guaranteed maximum high output voltage of at least 2.4 V, which may not be enough to drive the COMP pin of some PWM controllers. The EAOUT2 pin can drive ±1 mA and has an output range that guarantees 5.0 V for a VDD1 voltage range of 10 V to 20 V, which works well with the COMP pin of many PWM controllers. In an application where the 5 V minimum output of the EAOUT2 pin is not enough to drive the COMP pin of some PWM controllers, for example, controllers that operate with 6 V or more of COMP pin voltage, use EAOUT2 to drive the FB pin of the error amplifier of the PWM controller (see Figure 24). The typical VREF voltage level of PWM controllers is approximately 1.25 V or 2.5 V, setting the reference level for the FB pin. In Figure 24, the As shown in Figure 24, the ADuM3190 op amp has the feedback voltage from the VOUT output divider is connected to the +IN pin, and the +1.225 V reference voltage connected to the −IN pin. This configuration produces a low going ADuM3190 COMP pin when the VOUT voltage drops from a load step. The EAOUT2 pin follows the COMP pin, going low and connecting to the PWM controller FB pin. The error amplifier of the PWM controller has a reference (VREF) at the noninverting input, which, when the FB pin is low, makes the COMP pin of the error amplifier output go high. A high at the COMP pin causes the latching PWM comparator to produce a PWM duty cycle output. This PWM duty cycle output drives the power stage to increase the VOUT voltage until it returns to regulation. The application block diagrams (see Figure 23 and Figure 24) show two different ways to use the ADuM3190 to provide isolated feedback in the control loop of an isolated dc-to-dc converter. In both figures, the loop is closed at approximately the 1.225 V reference voltage, providing ±1% accuracy over temperature. The ADuM3190 op amp has a high gain bandwidth of 10 MHz to allow the dc-to-dc converter to operate at high switching speeds, enabling smaller values for the Output Filter L and Output Filter C components. The 400 kHz bandwidth of the ADuM3190 error amplifier output offers faster loop response for better transient response than the typical shunt regulator and optocoupler solutions, which typically have bandwidths of only 25 kHz to 50 kHz maximum. SETTING THE OUTPUT VOLTAGE The output voltage in the application circuit can be set with two resistors in a voltage divider, as shown in Figure 25. The output voltage is determined by the following equation, where VREF = 1.225 V: Rev. 0 | Page 13 of 16 VOUT = VREF × (R1 + R2)/R2 (1) ADuM3190 Data Sheet VOUT R1 VIN = 0.35V TO 1.5V +IN VREF 1.225V R2 11335-010 REFOUT ADuM3190 Figure 25. Setting the Output Voltage DOSA MODULE APPLICATION Figure 26 is a block diagram of a Distributed-power Open Standards Alliance (DOSA) circuit using the ADuM3190. The block diagram shows how to use the ADuM3190 1.225 V reference and the error amp in a DOSA standard power supply module circuit to produce output voltage settings using a combination of resistors. The ADuM3190 1.225 V reference is specified for ±1% over the −40°C to +125°C temperature range. See Table 10 to select the resistor values to set the output voltage of the module. Two different ranges of VOUT can be implemented, VOUT > 1.5 V or VOUT < 1.5 V, depending on the required module. VOUT DOSA MODULE R1 VIN = 0.35V TO 1.5V R2 ERROR AMP R3 VREF 1.225V R5 R4 RTRIM-DOWN R6 Figure 26. DOSA Module Table 10. Resistor Values for DOSA Module Module Nominal Output VOUT > 1.5 V VOUT < 1.5 V VOUT > 1.5 V VOUT < 1.5 V R3 1 kΩ 1 kΩ 5.11 kΩ 5.11 kΩ R4 1 kΩ 0Ω 5.11 kΩ 0Ω R5 0Ω 2.05 kΩ 0Ω 10.5 kΩ V = (−dβ/dt) ∑π rn2, n = 1, 2, … , N where: β is the magnetic flux density (gauss). rn is the radius of the nth turn in the receiving coil (cm). N is the number of turns in the receiving coil. Given the geometry of the receiving coil in the ADuM3190 and an imposed requirement that the induced voltage be, at most, 50% of the 0.5 V margin at the decoder, a maximum allowable magnetic field is calculated, as shown in Figure 27. 100 OPTIONAL TRIM-UP OR TRIM-DOWN RESISTOR OR ±10% OF NOMINAL VALUE ACCORDING TO DOSA 11335-011 ADuM3190 RTRIM-UP The ADuM3190 is immune to external magnetic fields. The limitation on the ADuM3190 magnetic field immunity is set by the condition whereby induced voltage in the transformer receiving coil is sufficiently large to either falsely set or reset the decoder. The following analysis defines the conditions under which this can occur. The 3 V operating condition of the ADuM3190 is examined because it represents the most susceptible mode of operation. The pulses at the transformer output have an amplitude that is greater than 1.0 V. The decoder has a sensing threshold at approximately 0.5 V, therefore establishing a 0.5 V margin within which induced voltages are tolerated. The voltage induced across the receiving coil is given by R6 Open 1.96 kΩ Open 10.0 kΩ DC CORRECTNESS AND MAGNETIC FIELD IMMUNITY Positive and negative logic transitions at the isolator input cause narrow (~1 ns) pulses to be sent to the decoder via the transformer. The decoder is bistable and is, therefore, either set or reset by the pulses, indicating input logic transitions. In the absence of logic transitions of more than 1 µs at the input, a periodic set of refresh pulses indicative of the correct input state are sent to ensure dc correctness at the output. If the decoder receives no internal pulses for more than approximately 3 µs, the input side is assumed to be unpowered or nonfunctional, in which case, the isolator output is forced to 10 1 0.1 0.01 0.001 1k 10k 100k 1M 10M 100M MAGNETIC FIELD FREQUENCY (Hz) 11335-012 –IN ERROR AMP a default high impedance state by the watchdog timer circuit. In addition, the outputs are in a default high impedance state while the power is increasing before the UVLO threshold is crossed. MAXIMUM ALLOWABLE MAGNETIC FLUX DENSITY (kgauss) ISOLATED DC-TO-DC SUPPLY Figure 27. Maximum Allowable External Magnetic Flux Density For example, at a magnetic field frequency of 1 MHz, the maximum allowable magnetic field of 0.02 kgauss induces a voltage of 0.25 V at the receiving coil. This is approximately 50% of the sensing threshold and does not cause a faulty output transition. Similarly, if such an event were to occur during a transmitted pulse (and had the worst-case polarity), the received pulse is reduced from >1.0 V to 0.75 V, still well above the 0.5 V sensing threshold of the decoder. The preceding magnetic flux density values correspond to specific current magnitudes at given distances away from the ADuM3190 transformers. Figure 28 shows these allowable current magnitudes as a function of frequency for selected distances. As shown Figure 28, the ADuM3190 is immune and can Rev. 0 | Page 14 of 16 Data Sheet ADuM3190 be affected only by extremely large currents operating at a high frequency very close to the component. For the 1 MHz example, a 0.7 kA current must be placed 5 mm away from the ADuM3190 to affect the operation of the device. DISTANCE = 1m A bipolar ac voltage environment is the worst case for the iCoupler products yet meets the 50-year operating lifetime recommended by Analog Devices for maximum working voltage. In the case of unipolar ac or dc voltage, the stress on the insulation is significantly lower. This allows operation at higher working voltages while still achieving a 50-year service life. Treat any cross-insulation voltage waveform that does not conform to Figure 30 or Figure 31 as a bipolar ac waveform, and limit its peak voltage to the 50-year lifetime voltage value listed in Table 8. 100 10 DISTANCE = 100mm 1 DISTANCE = 5mm 100k 1M 10M MAGNETIC FIELD FREQUENCY (Hz) 100M Figure 28. Maximum Allowable Current for Various Current-to-ADuM3190 Spacings INSULATION LIFETIME Note that the voltage presented in Figure 30 is shown as sinusoidal for illustration purposes only. It is meant to represent any voltage waveform varying between 0 V and some limiting value. The limiting value can be positive or negative, but the voltage cannot cross 0 V. RATED PEAK VOLTAGE All insulation structures eventually break down when subjected to voltage stress over a sufficiently long period. The rate of insulation degradation is dependent on the characteristics of the voltage waveform applied across the insulation. In addition to the testing performed by the regulatory agencies, Analog Devices carries out an extensive set of evaluations to determine the lifetime of the insulation structure within the ADuM3190. Analog Devices performs accelerated life testing using voltage levels higher than the rated continuous working voltage. Acceleration factors for several operating conditions are determined. These factors allow calculation of the time to failure at the actual working voltage. The values shown in Table 8 summarize the peak voltage for 50 years of service life for a bipolar ac operating condition. In many cases, the approved working voltage is higher than the 50-year service life voltage. Operation at these high working voltages can lead to shortened insulation life in some cases. Rev. 0 | Page 15 of 16 11335-014 10k 0V Figure 29. Bipolar AC Waveform RATED PEAK VOLTAGE 11335-015 0.01 1k 0V Figure 30. Unipolar AC Waveform RATED PEAK VOLTAGE 11335-016 0.1 11335-013 MAXIMUM ALLOWABLE CURRENT (kA) 1000 The ADuM3190 insulation lifetime depends on the voltage waveform type imposed across the isolation barrier. The iCoupler insulation structure degrades at different rates depending on whether the waveform is bipolar ac, unipolar ac, or dc. Figure 29, Figure 30, and Figure 31 illustrate these different isolation voltage waveforms. 0V Figure 31. DC Waveform ADuM3190 Data Sheet PACKAGING AND ORDERING INFORMATION OUTLINE DIMENSIONS 0.197 (5.00) 0.193 (4.90) 0.189 (4.80) 9 1 8 0.244 (6.20) 0.236 (5.99) 0.228 (5.79) 0.010 (0.25) 0.006 (0.15) 0.069 (1.75) 0.053 (1.35) 0.065 (1.65) 0.049 (1.25) 0.010 (0.25) 0.004 (0.10) COPLANARITY 0.004 (0.10) 0.158 (4.01) 0.154 (3.91) 0.150 (3.81) 0.025 (0.64) BSC 0.012 (0.30) 0.008 (0.20) SEATING PLANE 8° 0° 0.020 (0.51) 0.010 (0.25) 0.050 (1.27) 0.016 (0.41) COMPLIANT TO JEDEC STANDARDS MO-137-AB CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 0.041 (1.04) REF 01-28-2008-A 16 Figure 32. 16-Lead Shrink Small Outline Package [QSOP] (RQ-16) Dimensions shown in inches and (millimeters) ORDERING GUIDE Model1 ADuM3190ARQZ ADuM3190ARQZ-RL7 ADuM3190BRQZ ADuM3190BRQZ-RL7 ADuM3190SRQZ ADuM3190SRQZ-RL7 ADuM3190TRQZ ADuM3190TRQZ-RL7 EVAL-ADuM3190EBZ 1 Temperature Range −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C Bandwidth (Typical) 200 kHz 200 kHz 400 kHz 400 kHz 200 kHz 200 kHz 400 kHz 400 kHz Package Description 16-Lead QSOP 16-Lead QSOP 16-Lead QSOP 16-Lead QSOP 16-Lead QSOP 16-Lead QSOP 16-Lead QSOP 16-Lead QSOP Evaluation Board Z = RoHS Compliant Part. ©2013 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D11335-0-2/13(0) www.analog.com/ADuM3190 Rev. 0 | Page 16 of 16 Package Option RQ-16 RQ-16 RQ-16 RQ-16 RQ-16 RQ-16 RQ-16 RQ-16 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Analog Devices Inc.: ADUM3190ARQZ ADUM3190ARQZ-RL7 ADUM3190BRQZ ADUM3190BRQZ-RL7 ADUM3190SRQZ ADUM3190SRQZ-RL7 ADUM3190TRQZ ADUM3190TRQZ-RL7