® ISO508 ISO 508 ISO 508 For most current data sheet and other product information, visit www.burr-brown.com Uni-Directional ISOLATED DIGITAL COUPLERS FEATURES DESCRIPTION ● LOW POWER CONSUMPTION: < 12mW per Channel Typ. ● 1500Vrms ISOLATION: 100% Tested by Partial Discharge ISO508 is an 8-channel, isolated, digital coupler based on the Burr-Brown capacitive barrier technology. The ISO508 has additional circuitry to ensure DC accuracy and overcome the edge-sensitive nature of normal capacitive devices even on power-up conditions. The novel circuitry involved will restore the correct output after a transient interruption should that be necessary. ● ASYNCHRONOUS OR SYNCHRONOUS OPERATION ● DOUBLE BUFFERED DESIGN FOR EASY INTEGRATION INTO BUS-BASED SYSTEMS The ISO508 is designed with input and output buffers for ease of integration into a µP bus system. The output buffer has tri-state capability, and by the use of OE, the output data bus lines can be made to go high impedance. This feature of the ISO508, which allows multiple access to a data bus, requires extra circuitry when using an alternative solution. ● TRI-STATE OUTPUTS ● 24-PIN PDIP OR GULL WING PACKAGES ● 2MWORDS/SEC TRANSFER RATE ● 1µSEC TRANSIENT RECOVERY ISO508 will transfer an 8-bit word at rates up to 2Mwords/s without the skew problems associated in implementing this function with optocouplers. The ISO508 is available in 24-pin PDIP or 24-pin Gull Wing packages. Both are specified for operation from –40°C to +85°C. APPLICATIONS ● PARALLEL ADCs/DACs ● DIGITAL INTERFACES ● DIGITAL TRANSMISSION ● GROUND-LOOP ISOLATION DATA IN L L S S L L A A H H A A T T I I T T C C F F C C H H T T H H LEI DATA OUT OE CONT LEO International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111 Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 ® © 1998 Burr-Brown Corporation PDS-1422B 1 Printed in U.S.A. June, 1999 ISO508 SPECIFICATIONS At TA = +25°C, and VS = +5V, unless otherwise noted. ISO508P, P-U PARAMETER ISOLATION Rated Voltage, Continuous Partial Discharge Voltage Barrier Impedance Leakage Current VISO TIMING LE Width (LOW) LE Width (HIGH) Data Set-Up to LEI Data Hold from LEI Propagation Delay Data Output Delay Output Rise and Fall Time Output Enable Output Disable Skew Max Data Transfer Rate (Sync) (Cont) MIN 50Hz, 60Hz 1s, 5x5pC/cycle(1) 1500 2500 VIH VIL I PD IL IH CIN VOH VOL I OS tWL tIL t SU tH t PD t DD tOD t OE tDIS TYP MAX >1014, 10 1 240V, 60Hz 2500V, 50Hz PDIP = “P” Package PDIP = “P” Package 5kV/µs Edge Creepage Distance Internal Isolation Distance Transient Recovery Time DC CHARACTERISTICS High Level Input Voltage Low Level Input Voltage Input Pull-Down Current (Cont, OE) Input Leakage Current High Z Leakage Current Input Capacitance High Level Output Voltage Low Level Output Voltage Output Short-Circuit Current CONDITIONS 12 11 0.1 1 See Note 2 See Note 2 VIN = 5V LEI, LEO, D0-7 2 VS = 4.4 - 4.5, IOH = 6mA I OL = 6mA 1 second, max VS – 1 0.8 50 5 1 1 5 LEI HI to LO LEI HI to LO Data In to Data Out (Cont) LEI LOW to Data Out (Sync) LEO High to Data Out Change 10% to 90%, CL = 50pF OE to Data Valid High or Low OE to Data Hi-Z Between any 2 Channels 0.4 30 50 15 0 20 9 1000 520 35 14 35 25 5 2 1 POWER Supply Voltage Supply Current VSA, VSB ISA Supply Current ISB Either Side Transmit Side DC Transmit Side DC Max Rate Receive Side DC Receive Side Max Rate TEMPERATURE RANGE Operating Storage Thermal Resistance, θJA 4.5 5 7 8 12 –40 –40 75 UNITS V V ΩpF µA µA mm mm µs V V µA nA nA pF V V mA ns ns ns ns ns ns ns ns ns ns ns Mw/s Mw/s 5.5 10 15 12 20 V mA mA mA mA +85 +125 °C °C °C/W NOTES: (1) All devices receive a 1s test. Failure criterion is 5 pulses of ≥ 5pC per cycle. (2) Logic inputs are HCT-type and thresholds are a function of power supply voltage with approximately 400mV hysteresis. 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. ® ISO508 2 FUNCTIONAL DESCRIPTION PIN CONFIGURATION Top View DIP VSA 1 24 GNDB CONT 2 23 LEO DIN0 3 22 DOUT0 DIN1 4 21 DOUT1 DIN2 5 20 DOUT2 DIN3 6 19 DOUT3 DIN4 7 18 DOUT4 DIN5 8 17 DOUT5 DIN6 9 16 DOUT6 DIN7 10 15 DOUT7 LEI 11 14 OE GNDA 12 13 VSB ISO508 NAME FUNCTION DIN (0 - 7) Input Data Bus. Inputs are CMOS/TTL compatible. DOUT (0 - 7) Output Data Bus. Outputs are TTL compatible. LEI Input Latch Enable. Latch enable signal for the input data buffer. A logic LOW will latch the input data preventing further changes being made before data transmission across the barrier, and transmit if in synchronous mode. A logic HIGH will allow the data to pass from the input pins to the input buffer. LEO Output Latch Enable. Latch enable signal for the output data buffer. A logic LOW will latch the internal data to the output pins and prevent further changes to the output data. A logic HIGH will allow the internal data to be passed to the output pins as soon as it becomes available. CONT Synchronous/Asynchronous Mode Select. A logic HIGH selects asynchronous mode. A logic LOW selects synchronous mode. OE Output Tri-State Enable. Makes the output data pins high impedance to allow multiple parallel access to the data bus. A logic HIGH will make DOUT (0 - 7) high impedance. A logic LOW will allow DOUT (0 - 7) to be driven to the correct logic level. ELECTROSTATIC DISCHARGE SENSITIVITY ABSOLUTE MAXIMUM RATINGS Supply Voltage: VSA ............................................................. –0.5V to +6V VSB ............................................................. –0.5V to +6V Maximum Input Current, any Input Pin ............................................. 20mA Continuous Isolation Voltage ..................................................... 1500Vrms Storage Temperature ...................................................... –40°C to +125°C Lead Temperature (soldering, 10s) ............................................... +260°C Electrostatic discharge can cause damage ranging from performance degradation to complete device failure. BurrBrown Corporation recommends that all integrated circuits be handled and stored using appropriate ESD protection methods. 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. PACKAGE INFORMATION PRODUCT PACKAGE PACKAGE DRAWING NUMBER(1) ISO508P ISO508P-U 24-Pin Plastic DIP 24-Pin Gull Wing Surface Mount 167 167-4 NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. ® 3 ISO508 OPERATION ISO508 has two modes of operation: synchronous and asynchronous. The mode is selected by the CONT pin. CONT held low selects synchronous operation while CONT held high will select asynchronous operation. In synchronous mode the user has control of the time at which the data is transmitted across the barrier, while in asynchronous mode the data is continually transmitted across the barrier under the internal logic control. The input latches and output latches are level sensitive. INPUT DATA n–1 DATA n BARRIER DATA n+1 DATA n–1 ASYNCHRONOUS MODE When CONT is held high, the internal transmission circuit is in control and will initiate data transmission asynchronously at 1MWords/s i.e., 1Mbps on each of the 8 channels. ACTIVE The asynchronous mode runs continuously under the internal controls. LEI can serve as an input data latch, but will not control the data transmission across the barrier. As in the synchronous mode, LEI and LEO can be used to select of ignore input or output data respectively. FIGURE 1. Data Transfer—Synchronous Mode. If LEI is taken high when transmission is in progress, the input data is recaptured in the input buffer without interfering with the transmitting data. If LEI then goes low while transmission is still in progress the current transmission will be terminated and restarted with the new data. The last full data transmission will not be affected. INPUT DATA n–1 DATA n DATA n+1 DATA n+2 LEI BARRIER ACTIVE n–1 ACTIVE n ACTIVE n ACTIVE n+2 LEO OUTPUT DATA DATA n–1 FIGURE 3. Data Transfer—Asynchronous Mode. ® ISO508 ACTIVE The output data changes under the control of LEO. If LEO is high at the end of a transmission, the output data will change immediately the transmission is complete. If LEO is low at the end of transmission, the output data will change when LEO goes high. In both cases all data bits will change together guaranteeing the specified skew performance. Transmitted data can be ignored selectively, if desired, by maintaining LEO low until the desired data is available. DATA n DATA n–1 DATA n+2 FIGURE 2. Data Transfer—Synchronous Mode Restart. LEO OUTPUT DATA ACTIVE ACTIVE OUTPUT DATA DATA n+1 ACTIVE DATA n+1 LEO LEI BARRIER DATA n LEI SYNCHRONOUS MODE With CONT held low, the input data is transmitted across the barrier under the control of LEI. When LEI is held low, no data is passed to the input buffer and no barrier transmission takes place. When LEI goes high, data is transferred to the input buffer. On the falling edge of LEI the data is then transmitted across the barrier. INPUT DATA n–1 4 DATA n n+2 DATA CORRUPTION LEI goes low data will be transmitted (clocked) across the barrier. Depending on when LEI goes low, in relation to the internal clock cycle, will determine the “jitter” between successive input data transfers. This can be maximum of 50ns. In either synchronous or asynchronous mode if the data is upset by a transient the complete transmission is invalid. However, in asynchronous mode the data is being sent continuously and will therefore correct the corrupted information within a maximum of 1µs. In synchronous mode, data transfer is under the control of the user, and retransmission would be required by the software. In asynchronous mode the input data is transferred by the internal clock and logic control, i.e., 2 sync. Clock cycles., (S0, and S1), 8 data clock cycles. Depending on when the input data is presented, in relation to the start of the data block transmission, will determine the “jitter” between successive input data transfers. This can be maximum of 500ns. DATA TRANSMISSION AND JITTER Because the internal 20MHz clock is free-running, two “jitter” conditions are possible. In synchronous mode when INPUT DATA n–1 DATA n DATA n+1 DATA n+2 tWH tWL LEI LEI BARRIER ACTIVE ACTIVE ACTIVE DATA IN LEO DATA OUT OUTPUT DATA DATA n–1 Invalid tPD(sync) DATA n+1 tH tSU FIGURE 4. Data Corruption. tDD LEO INPUT DATA LEI DATA OUT INT. CLK OE tEN “JITTER” tDIS FIGURE 5. Jitter in Synchronous Mode. DATA IN INPUT DATA DATA OUT LEI INT. CLK 2 1 0 S1 S0 7 6 5 4 3 2 tPD(sync) 1 “JITTER” FIGURE 6. Jitter in Asynchronous Mode. FIGURE 7. Timing Diagrams. ® 5 ISO508 +VISO DGND VSB All inductors 100µH. All capacitors 10µF tantalum. AGND +15V +5V –VISO +VISO +VSS 27 +15V VSA IN1 20 +5V GND1 IN2 21 IN3 22 +VISO IN4 23 IN5 24 OUT IN6 25 11 10 5 8 PGA205 A0 10 4 A1 15 16 14 IN10 9 +VISO –VISO 13 5 28 IN7 MPC506 IN8 12 GND IN9 26 12 11 1 8 2 12 11 15 +VSS –VSS VIN 9 10 ISO124 16 8 GND IN13 6 IN14 5 7 GND1 IN12 7 –15V –VISO 13 PGA205 A0 10 4 A1 15 16 14 –VSS +VISO –VISO IN11 8 4 –15V –VISO 1 19 Isolated Supplies GND IN15 IN16 A3 A2 A1 A3 A2 A0 14 15 16 17 GAIN A3 A2 A1 A0 1 0 0 0 0 2 0 0 1 0 4 0 1 0 0 8 0 1 1 0 16 1 1 1 0 32 0 1 1 1 64 1 1 1 1 VSB A1 A0 LEO 23 22 21 20 19 18 17 16 15 14 OE 1 ISO508 VSA 11 LEI 3 4 5 6 7 8 9 10 2 CONT GND1 FIGURE 8. Isolated 16-Channel Variable Gain DAS. VSA VSB 1 13 DIN0 3 22 DOUT0 DIN1 4 21 DOUT1 DIN2 5 20 DOUT2 DIN3 6 19 DOUT3 DIN4 7 C 18 DOUT4 DIN5 8 H 17 DOUT5 DIN6 9 16 DOUT6 DIN7 10 15 DOUT7 L A T L S S L L A H H A A T I I T T C F F C C H T T H H 23 14 11 OE VSB LEI 11 23 LEO CONT 2 24 GNDB GNDA 12 FIGURE 9. Isolated 8-Channel Output Bus (Asynchronous Operation). ® ISO508 6 VSB