® ISO107 High-Voltage, Internally Powered ISOLATION AMPLIFIER FEATURES APPLICATIONS ● SIGNAL AND POWER IN ONE TRIPLE-WIDE PACKAGE ● 8000Vpk TEST VOLTAGE ● 2500Vrms CONTINUOUS AC BARRIER RATING ● WIDE INPUT SIGNAL RANGE: –10V to +10V ● WIDE BANDWIDTH: 20kHz Small Signal, 20kHz Full Power ● BUILT-IN ISOLATED POWER: ±10V to ±18V Input, ±50mA Output ● MULTICHANNEL SYNCHRONIZATION CAPABILITY (TTL) ● MULTICHANNEL ISOLATED DATA ACQUISITION ● BIOMEDICAL INSTRUMENTATION ● POWER SUPPLY AND MOTOR CONTROL ● GROUND LOOP ELIMINATION ISO107 BLOCK DIAGRAM Sense VIN Duty Cycle Modulator Com 1 +VCC1 Sync Gnd 1 Rectifiers Filters –VCC1 Duty Cycle Demodulator VOUT Com 2 –VCC2 Sync +VCC2 Oscillator Driver Enable Gnd 2 DESCRIPTION The ISO107 isolation amplifier provides both signal and power across an isolation barrier. The ceramic side-brazed hybrid package contains a transformercoupled DC/DC converter and a capacitor-coupled signal channel. Extra power is available on the isolated input side for external input conditioning circuitry. The converter is protected from shorts to ground with an internal current limit, and the soft-start feature limits the initial currents from the power source. Multiple-channel synchronization can be accomplished by applying a TTL clock signal to paralleled Sync pins. The Enable con- trol is used to turn off transformer drive while keeping the signal channel demodulator active. This feature provides a convenient way to reduce quiescent current for low power applications. The wide barrier pin spacing and internal insulation allow for the generous 2500Vrms continuous rating. Reliability is assured by 100% barrier breakdown testing that conforms to UL544 test methods. Low barrier capacitance minimizes AC leakage currents. These specifications and built-in features make the ISO107 easy to use, as well as providing for compact PC board layouts. International Airport Industrial Park • Mailing Address: PO Box 11400 Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706 Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 © 1989 Burr-Brown Corporation PDS-898C Printed in U.S.A. October, 1993 SPECIFICATIONS ELECTRICAL TA = +25°C and VCC2 = ±15V, ±15mA output current unless otherwise noted. PARAMETERS MAX UNITS 100 160 1012 || 13 1.2 2 Vrms VDC Vpk dB dB Ω || pF µA GAIN Nominal Initial Error Gain vs Temperature Nonlinearity 1 ±0.1 ±50 ±0.01 ±0.25 ±120 ±0.025 V/V % FSR ppm/°C % FSR INPUT OFFSET VOLTAGE Initial Offset vs Temperature vs Power Supplies ±20 ±150 ±2 ISOLATION Rated Continuous Voltage (1) AC, 60Hz DC Test Breakdown, AC, 60Hz Isolation-Mode Rejection Barrier Impedance Leakage Current CONDITIONS MIN TMIN to TMAX TMIN to TMAX 10s 2500Vrms, 60Hz 2121VDC 2500 3500 8000 240Vrms, 60Hz INPUT Voltage Range Resistance VCC2 = ±10V to ±18V Output Voltage in Range SIGNAL OUTPUT Voltage Range Current Drive Ripple Voltage, 800kHz Carrier (See Figure 4) Capacitive Load Drive Voltage Noise FREQUENCY RESPONSE Small Signal Bandwidth Slew Rate Settling Time POWER SUPPLIES Rated Voltage, VCC2 Voltage Range Input Current Ripple Current Rated Output Voltage Output Current Load Regulation Line Regulation Output Voltage vs Temperature Voltage Balance Error, ±VCC1 Voltage Ripple Output Capacitive Load (See Figure 1) Sync Frequency ±50 ±400 ±15 200 V kΩ ±10 ±5 ±12.5 ±15 20 1000 4 V mA mVp-p pF µV/√Hz 20 1.5 75 kHz V/µs µs ±10 ±15 No External Capacitors +75/–4.5 10 3 ±15 ±15 30 0.5 1.18 10 0.05 10 Sync-Pin Grounded(3) 1.6 ±14.25 Balanced Load Single Balanced Load ±18 ±15.75 ±50 100 1 TEMPERATURE RANGE Specification Operating Storage mV µV/°C mV/V ±10 0.1%, –10/10V IO = ±15mA(2) No Filter CIN = 1µF TYP –25 –25 –25 +85 +85 +125 V V mA mAp-p mAp-p V mA mA %/mA V/V mV/°C % mVp-p µF MHz °C °C °C NOTES: (1) Conforms to UL544 test methods. 100% tested at 2500Vrms for 1 minute. (2) For other conditions, see Performance Curve, Input Current (+VCC2) vs Output Current. Input Current (–VCC2) is constant at –4.5mA (typ) for all output currents. (3) If using external synchronization with a TTL-level clock, frequency should be between 1.2MHz and 2MHz with a duty-cycle greater than 25%. The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ® ISO107 2 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION Supply Without Damage .................................................................... ±18V VIN, Sense Voltage ............................................................................ ±50V Com 1 to Gnd 1 or Com 2 to Gnd 2 ........................................... ±200mV Enable, Sync ........................................................................... 0V to +VCC2 Continuous Isolation Voltage ..................................................... 2500Vrms VISO, dv/dt ...................................................................................... 20kV/µs Junction Temperature ...................................................................... 150°C Storage Temperature ..................................................... –25°C to +125°C Lead Temperature, (soldering, 10s) ................................................ 300°C Output Short to Gnd 2 Duration .............................................. Continuous ±VCC1 to Gnd 1 Duration .......................................................... Continuous Top View DIP NC 1 32 NC +VCC1 2 31 Gnd 1 NC 3 30 VIN –VCC1 4 29 Com 1 Com 2 13 20 –VCC2 VOUT 14 19 Sync* PACKAGE INFORMATION(1) MODEL PACKAGE PACKAGE DRAWING NUMBER ISO107 32-Pin Side-Braze Ceramic 210 NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix D of Burr-Brown IC Data Book. ELECTROSTATIC DISCHARGE SENSITIVITY Sense 15 18 +VCC2 Gnd 2 16 17 Enable *Operation requires that this pin be grounded or driven with TTL levels. Any integrated circuit can be damaged by ESD. Burr-Brown 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 published specifications. ® 3 ISO107 TYPICAL PERFORMANCE CURVES TA = +25°C, VCC2 = ±15VDC, ±15mA output current unless otherwise noted. RECOMMENDED RANGE OF ISOLATION VOLTAGE IMR/LEAKAGE vs FREQUENCY Barrier Voltage Rating 3.5k Non-Specified Signal Operation Operational Region 100 10 1 100 80 Leakage at 240 Vrms 100 1k 10k 100k 10µA 40 1µA 1M 10 100 Isolation Voltage Frequency (Hz) 1k 100nA 100k 10k Isolation Voltage Frequency (Hz) PSRR vs FREQUENCY GAIN/PHASE vs FREQUENCY 60 3 –45 Gain +VCC2 54 0 0 40 –3 –6 90 –9 135 –12 180 20 0 1k 10k 45 Phase Gain (dB) –VCC2 100 100µA 60 20 10 Power Supply Rejection Ratio (dB) 1mA –15 100 100k Supply Modulation Frequency (Hz) 300 1k 3k 10k 30k Phase Shift (°) 1k Leakage at 2500 Vrms IMR Barrier Leakage Current (rms) 10mA 120 Isolation-Mode Rejection (dB) Maximum Isolation Voltage (Vpk) 10k 225 100k Small Signal Frequency (Hz) ISOLATED POWER SUPPLY LOAD REGULATION AND EFFICIENCY LARGE SIGNAL TRANSIENT RESPONSE 20 18 60 10 0 –10 –20 16 45 Output Voltage Balanced Loads 14 Output Voltage Single-Ended Loads 12 10 0 50 100 0 0 Time (µs) ® ISO107 4 10 20 30 40 20 40 60 80 ±VCC1 Supply Output Current (mA) 30 15 0 50 100 Efficiency (%) ±VCC1 Output Voltage (V) Output Voltage (V) Balanced Load Efficiency TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, VCC2 = ±15VDC, ±15mA output current unless otherwise noted. ISOLATED POWER SUPPLY VOLTAGE vs TEMPERATURE ISOLATED POWER SUPPLY LINE REGULATION 19 2 18 17 ∆VCC1 (%) ±VCC1 (V) 1 ±15mA Load 16 15 14 1.18 V/V 13 12 0 –1 11 10 –2 9 9 10 11 12 13 14 15 16 17 18 19 –25 25 0 +VCC2 (V) ISOLATED SUPPLY VOLTAGE AND VOS vs SYNC FREQUENCY VOS 0 0 –2.5 –25 –5 –50 2 ∆VCC1 (mV) 25 2.5 ±VCC2 Input Current (mA) +VCC2 = 15V VCC1 ∆VOS (mV) 100 145 50 1.5 75 ISOLATED POWER SUPPLY INPUT CURRENT vs OUTPUT CURRENT 5 1 50 Temperature (°C) 120 95 70 45 0 2.5 10 20 30 40 50 +VCC1 Supply Balanced Output Current (mA) Sync Frequency (MHz) ® 5 ISO107 THEORY OF OPERATION OPTIONAL GAIN AND OFFSET ADJUSTMENTS Rated gain accuracy and offset performance can be achieved with no external adjustments, but the circuit of Figure 2a may be used to provide a gain trim of ±0.5% for the values shown; greater range may be provided by increasing the size of R1 and R1. Every 2kΩ increase in R1 will give an additional 1% adjustment range, with R2 ≥ R1. If safety or convenience dictates location of the adjustment potentiometer on the other side of the barrier from the position shown in Figure 2a, the position of R1 and R2 may be reserved. The block diagram on the front page shows the isolation amplifier’s synchronized signal and power configuration, which eliminates beat frequency interference. A proprietary 800kHz oscillator chip, power MOSFET transformer drivers, patented square core wirebonded transformer, and single chip diode bridge provide power to the input side of the isolation amplifier as well as external loads. The signal channel capacitively couples a duty-cycle encoded signal across the ceramic high-voltage barrier built into the package. A proprietary transmitter-receiver pair of integrated circuits, laser trimmed at wafer level, and coupled through a pair of matched “fringe” capacitors, result in a simple, reliable design. Gains greater than 1 may be obtained by using the circuit of Figure 2b. Note that the effect of input offset errors will be multiplied at the output in proportion to the increase in gain. Also, the small-signal bandwidth will be decreased in in2kΩ SIGNAL AND POWER CONNECTIONS Figure 1 shows the proper power supply and signal connections. All power supply pins should be bypassed as shown with the π filter for +VCC2 an option recommended if more than ±15mA are drawn from the isolated supply. The separate input and output common pins and output sense are low current inputs tied to the signal source ground, output ground, and output load, respectively, to minimize errors due to IR drop in long conductors. Otherwise, connect Com 1 to Gnd 1, Com 2 to Gnd 2, and Sense to VOUT at the ISO107 socket. The enable pin may be left open if the ISO107 is continuously operated. If not, a TTL low level will disable the internal DC/DC converter. The Sync input must be grounded for unsynchronized operation while a 1.2MHz to 2MHz TTL clock signal provides synchronization of multiple units. 1kΩ 30 R2 15 R1 VIN 29 13 VOUT 14 FIGURE 2a. Gain Adjust. 30 Sense 15 VIN 29 13 Gain = 1 + ( RR 1 2 VOUT 14 + R1 R1 ) 200k R2 FIGURE 2b. Gain Setting. Isolation Barrier –VCC2 C2 Com 1µF LI (3) + 31 NC 30 29 20 Gnd 1 VIN Com 1 19 –VCC2 Sync 18 +VCC2 1µF C1 VIN 17 10µF Tantalum +VCC2 Enable (2) (1) ISO107 NC +VCC1 LO* +VCC1 CO* NC 2 –VCC1 4 1µF max* Com 2 13 VOUT 14 1µF max* Sense Gnd 2 15 16 NOTES: (1) Enable = pin open or TTL high. (2) Ground sync if not used. (3) π filter reduces ripple current: LI = 10µH, <10Ω. Sense VOUT LO* –VCC1 Com 2 CO* Com Return FIGURE 1. Signal and Power Connections. ® ISO107 6 *Optional Filtering: LO = 10µH, <10Ω CO = 0.1 – 10pF ISOLATION BARRIER VOLTAGE The typical performance of the ISO107 under conditions of barrier voltage stress is indicated in the first two performance curves—Recommended Range of Isolation Voltage and IMR/Leakage vs Frequency. At low barrier modulation levels, errors can be determined by the IMRR characteristic. At higher barrier voltages, typical performance is obtained as long as the dv/dt across the barrier is below the shaded area in the first curve. Otherwise, the signal channel will be interrupted, causing the output to distort, and/or shift DC level. This condition is temporary, with normal operation resuming as soon as the transient subsides. Permanent damage to the integrated circuits occurs only if transients exceed 20kV/µs. Even in this extreme case, the barrier integrity is assured. verse proportion to the increase in gain. In most instances, a precision gain block at the input of the isolation amplifier will provide better overall performance. Figure 3 shows a method for trimming VOS of the ISO107. This circuit may be applied to either Signal Com (input or output) as desired for safety or convenience. With the values shown, ±15V supplies and unity gain, the circuit will provide ±150mV adjustment range and 0.25mV resolution with a typical trim potentiometer. The output will have some sensitivity to power supply variations. For a ±100mV trim, power supply sensitivity is 8mV/V at the output. +VCC1 or +VCC2 1MΩ Signal Com 1 or Signal Com 2 100kΩ HIGH VOLTAGE TESTING The ISO107 was designed to reliably operate with 2500Vrms continuous isolation barrier voltage. To confirm barrier integrity, a two-step breakdown test is performed on 100% of the units. First, an 8000V peak, 60Hz barrier potential is applied for 10s to verify that the dielectric strength of the insulation is above this level. Following this exposure, a 2500Vrms, 60Hz potential is applied for one minute to conform to UL544. Life-test results show reliable operation under continuous rated voltage and maximum operating temperature conditions. 10kΩ –VCC1 or –VCC2 FIGURE 3. VOS Adjust. OPTIONAL OUTPUT FILTER Figure 4 shows an optional output ripple filter that reduces the 800kHz ripple voltage to <3mVp-p without compromising DC performance. The small signal bandwidth is extended above 30kHz as a result of this compensation. Sense 30 400Ω 15 VIN 29 13 VOUT 14 4.7nF FIGURE 4. Ripple Reduction. MULTICHANNEL SYNCHRONIZATION Synchronization of multiple ISO107s can be accomplished by connecting pin 19 of each device to an external TTL level oscillator, as shown in Figure 6. The PWS750-1 oscillator is convenient because its nominal synchronizing output frequency is 1.6MHz, resulting in a 800kHz carrier in the ISO107 (its nominal unsynchronized value). The open collector output typically switches 7.5mA to a 0.2V low level so that the external pull-up resistor can be chosen for different pull-up voltages as shown in Figure 6. The number of channels synchronized by one PWS750-1 is determined by the total capacitance of the sync voltage conductors. They must be less than 1000pF to ensure TTL level switching at 800kHz. At higher frequencies the capacitance must be proportionally lower. Customers can supply their own TTL level synchronization logic, provided the frequency is between 1.2MHz and 2MHz, and the duty cycle is greater than 25%. ® 7 ISO107 APPLICATIONS + + +15V R8 R9 2kΩ 100kΩ R1 330kΩ 1 – 11, 12 16 R4 RA Q1 C1 2.2nF R2 Q2 330kΩ C2 10nF R6 10kΩ – IC2A RL 6 C3 0.33µF 5 – + 4 – 7 IC2B 31 R7 29 19 10kΩ Q4 20 13 16 4 Q3 R14 10kΩ R11 10kΩ C4 0.1µF 2 3 – IC2 Q1, Q2, Q4 Q3 D1 R1, R2, R3 R4, R5 IC1, IC3 Bypass IC2 Bypass *Burr-Brown P/N –15V OPA2111* 2N3904 2N7000 IN4148 1%, 1/2W 1%, 2210Ω 1.0µF 0.1µF FIGURE 5. ECG Amplifier with Right Leg Drive, Defibrillator Protection, and E.S.U. Blanking. –VCC2 +VCC2 VIN1 31 30 29 20 19 18 Sync ≈ 1.6MHz Channel 1 ISO 12 107 14 11 PWS750-1 3 2 4 13 14 15 16 + – 7 R VIN2 31 30 29 20 19 18 NOTES: (1) PWS750-1 can sync >20 ISO107s. (2) Bypass supplies as shown in Figure 1. Channel 2 ISO 107 VOUT1 2 4 13 14 15 16 + – VOUT2 Additional Channels FIGURE 6. Synchronized-Multichannel Isolation. ® ISO107 VOUT 2kΩ R13 IC3 ISO107* D1 10MΩ R12 + – 8 R3 9 7 3 + 2 + 330kΩ R10 100kΩ 6 LA 14 15 10 IC1 INA110* R5 18 2 30 8 8