IL300-F. Linear Optocoupler, High Gain Stability, Wide Bandwidth. Vishay Semiconductors

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1 Linear Optocoupler, High Gain Stability, Wide Bandwidth Features Couples AC and DC signals. % Servo Linearity Wide Bandwidth, > khz High Gain Stability, ±. %/ C Low Input-Output Capacitance Low Power Consumption, < mw Isolation Test Voltage, 3 V RMS,. sec. Internal Insulation Distance, >. mm for VDE Component in accordance to RoHS /9/EC and WEEE /9/EC i9 C A C A 3 K K NC NC C A Agency Approvals UL File #E DIN EN -- (VDE) DIN EN -- pending Available with Option, Add -X Suffix Applications Power Supply Feedback Voltage/Current Medical Sensor Isolation Audio Signal Interfacing Isolated Process Control Transducers Digital Telephone Isolation Description The Linear Optocoupler consists of an AlGaAs IRLED irradiating an isolated feedback and an output PIN photodiode in a bifurcated arrangement. The feedback photodiode captures a percentage of the LED s flux and generates a control signal (I P ) that can be used to servo the LED drive current. This technique compensates for the LED s non-linear, time, and temperature characteristics. The output PIN photodiode produces an output signal (I P ) that is linearly related to the servo optical flux created by the LED. The time and temperature stability of the input-output coupler gain (K3) is insured by using matched PIN photodiodes that accurately track the output flux of the LED. Order Information Part Remarks K3 =. -., DIP- -DEFG K3 =. -., DIP- -EF K3 =. -., DIP- -E K3 =. -.9, DIP- -F K3 =.9 -., DIP- -X K3 =. -., DIP- mil (option ) -X K3 =. -., SMD- (option ) -X9 K3 =. -., SMD- (option 9) -DEFG-X K3 =. -., DIP- mil (option ) -DEFG-X K3 =. -., SMD- (option ) -DEFG-X9 K3 =. -., SMD- (option 9) -EF-X K3 =. -., DIP- mil (option ) -EF-X K3 =. -., SMD- (option ) -EF-X9 K3 =. -., SMD- (option 9) -E-X K3 =. -.9, DIP- mil (option ) -E-X K3 =. -.9, SMD- (option ) -E-X9 K3 =. -.9, SMD- (option 9) -F-X K3 =.9 -., DIP- mil (option ) -F-X K3 =.9 -., SMD- (option ) -F-X9 K3 =.9 -., SMD- (option 9) For additional information on the available options refer to Option Information.

2 Operation Description A typical application circuit (Figure ) uses an operational amplifier at the circuit input to drive the LED. The feedback photodiode sources current to R connected to the inverting input of U. The photocurrent, I P, will be of a magnitude to satisfy the relationship of (I P = V IN /R). The magnitude of this current is directly proportional to the feedback transfer gain (K) times the LED drive current ( V IN /R = K I F ). The op-amp will supply LED current to force sufficient photocurrent to keep the node voltage (Vb) equal to Va. The output photodiode is connected to a non-inverting voltage follower amplifier. The photodiode load resistor, R, performs the current to voltage conversion. The output amplifier voltage is the product of the output forward gain (K) times the LED current and photodiode load, R ( V O = I F K R). Therefore, the overall transfer gain (V O /V IN ) becomes the ratio of the product of the output forward gain (K) times the photodiode load resistor (R) to the product of the feedback transfer gain (K) times the input resistor (R). This reduces to V O /V IN =(K R)/(K R). The overall transfer gain is completely independent of the LED forward current. The transfer gain (K3) is expressed as the ratio of the output gain (K) to the feedback gain (K). This shows that the circuit gain becomes the product of the transfer gain times the ratio of the output to input resistors V O /V IN = K3 (R/R). VISHAY K3-Transfer Gain Linearity The percent deviation of the Transfer Gain, as a function of LED or temperature from a specific Transfer Gain at a fixed LED current and temperature. Photodiode A silicon diode operating as a current source. The output current is proportional to the incident optical flux supplied by the LED emitter. The diode is operated in the photovoltaic or photoconductive mode. In the photovoltaic mode the diode functions as a current source in parallel with a forward biased silicon diode. The magnitude of the output current and voltage is dependent upon the load resistor and the incident LED optical flux. When operated in the photoconductive mode the diode is connected to a bias supply which reverse biases the silicon diode. The magnitude of the output current is directly proportional to the LED incident optical flux. LED (Light Emitting Diode) An infrared emitter constructed of AlGaAs that emits at 9 nm operates efficiently with drive current from µa to ma. Best linearity can be obtained at drive currents between. ma to ma. Its output flux typically changes by -. % / C over the above operational current range. Application Circuit K-Servo Gain The ratio of the input photodiode current (I P ) to the LED current (I F ) i.e., K = I P /I F. K-Forward Gain The ratio of the output photodiode current (I P ) to the LED current (I F ), i.e., K = I P /I F. K3-Transfer Gain The Transfer Gain is the ratio of the Forward Gain to the Servo gain, i.e., K3 = K/K. V CC Va + + Vin U Vb - R I F V CC lp 3 K K V CC V c lp R V CC - U + V out iil3_ Figure. Typical Application Circuit

3 VISHAY Absolute Maximum Ratings T amb = C, unless otherwise specified Stresses in excess of the absolute Maximum Ratings can cause permanent damage to the device. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operational sections of this document. Exposure to absolute Maximum Rating for extended periods of the time can adversely affect reliability. Input Parameter Test condition Symbol Value Unit Power dissipation P diss mw Derate linearly from C.3 mw/ C Forward current I F ma Surge current (pulse width < µs) I PK ma Reverse voltage V R. V Thermal resistance R th K/W Junction temperature T j C Output Parameter Test condition Symbol Value Unit Power dissipation P diss ma Derate linearly from C. mw/ C Reverse voltage V R V Junction temperature T j C Thermal resistance R th K/W Coupler Parameter Test condition Symbol Value Unit Total package dissipation at P tot mw C Derate linearly from C. mw/ C Storage temperature T stg - to + C Operating temperature T amb - to + C Isolation test voltage > 3 V RMS Isolation resistance V IO = V, T amb = C R IO > Ω V IO = V, T amb = C R IO > Ω 3

4 VISHAY Electrical Characteristics T amb = C, unless otherwise specified Minimum and maximum values are testing requirements. Typical values are characteristics of the device and are the result of engineering evaluation. Typical values are for information only and are not part of the testing requirements. Input LED Emitter Parameter Test condition Symbol Min Typ. Max Unit Forward voltage I F = ma V F.. V V F Temperature coefficient V F / C -. mv/ C Reverse current V R = V I R. µa Junction capacitance V F = V, f =. MHz C j pf Dynamic resistance I F = ma V F / I F. Ω Output Parameter Test condition Symbol Min Typ. Max Unit Dark current V det = - V, I F = µs I D. na Open circuit voltage I F = ma V D mv Short circuit current I F = ma I SC µa Junction capacitance V F =, f =. MHz C j pf Noise equivalent power V det = V NEP x W/ Hz

5 VISHAY Coupler Parameter Test condition Symbol Min Typ. Max Unit Input- output capacitance V F = V, f =. MHz. pf K, Servo gain (I P /I F ) I F = ma, V det = - V K... Servo current, see Note, I F = ma, V det = - V I P µa K, Forward gain (I P /I F ) I F = ma, V det = - V K.3.. Forward current I F = ma, V det = - V I P µa K3, Transfer gain (K/K) see I F = ma, V det = - V K3... K/K Note, Transfer gain linearity I F =. to ma K3 ±. % I F =. to ma, T amb = C to C ±. % Photoconductive Operation Frequency response I Fq = ma, MOD = ±. ma, R L = Ω BW (-3 db) KHz Phase response at khz V det = - V - Deg.. Bin Sorting: K3 (transfer gain) is sorted into bins that are ± %, as follows: Bin A =. -. Bin B =. -.9 Bin C = Bin D =. -.9 Bin E =. -.9 Bin F =.9 -. Bin G =. -. Bin H = Bin I =.9 -. Bin J =. -. K3 = K/K. K3 is tested at I F = ma, V det = - V.. Bin Categories: All s are sorted into a K3 bin, indicated by an alpha character that is marked on the part. The bins range from "A" through "J". The is shipped in tubes of each. Each tube contains only one category of K3. The category of the parts in the tube is marked on the tube label as well as on each individual part. 3. Category Options: Standard orders will be shipped from the categories that are available at the time of the order. Any of the ten categories may be shipped. For customers requiring a narrower selection of bins, four different bin option parts are offered. -DEFG: Order this part number to receive categories D,E,F,G only. -EF: Order this part number to receive categories E, F only. -E: Order this part number to receive category E only. Switching Characteristics Parameter Test condition Symbol Min Typ. Max Unit Switching time I F =. ma, I Fq = ma t r. µs t f. µs Rise time t r. µs Fall time t f. µs

6 VISHAY Common Mode Transient Immunity Parameter Test condition Symbol Min Typ. Max Unit Common mode capacitance V F =, f =. MHz C CM. pf Common mode rejection ratio f = Hz, R L =. KΩ CMRR 3 db Typical Characteristics (Tamb = C unless otherwise specified) IF - LED Current - ma iil3_ VF - LED Forward Voltage - V. IP - Servo Photocurrent - µa iil3_ 3 C C C C V D =V. Figure. LED Forward Current vs.forward Voltage Figure. Servo Photocurrent vs. LED Current and Temperature IF - LED Current - ma iil3_ VF - LED Forward Voltage - V IP - Servo Photocurrent - µa iil3_ C C C C V D = V. Figure 3. LED Forward Current vs.forward Voltage Figure. Servo Photocurrent vs. LED Current and Temperature

7 VISHAY Normalized Photocurrent iil3_ Normalized to: C C C C IP@ I F = ma, T A = C V D = V. NK - Normalized Servo Gain iil3_ C C C C C Normalized to: I F = ma,t A = C.. Figure. Normalized Servo Photocurrent vs. LED Current and Temperature Figure 9. Normalized Servo Gain vs. LED Current and Temperature IP - Normalized Photocurrent iil3_. Normalized to: C C C C IP@ I F = ma, T A = C V D = V.. K3 - Transfer Gain - (K/K) iil3_. C. C..99 C C.99 Figure. Normalized Servo Photocurrent vs. LED Current and Temperature Figure. Transfer Gain vs. LED Current and Temperature NK - Normalized Servo Gain iil3_ C C C C C. K3 - Transfer Gain - (K/K) iil3_ C C C C Normalized to: I F =ma, T A = C.99 Figure. Servo Gain vs. LED Current and Temperature Figure. Normalized Transfer Gain vs. LED Current and Temperature

8 VISHAY Amplitude Response - db I F = ma, Mod = ±. ma (peak) R L =. KΩˇ - - R L = KΩˇ - - F - Frequency - Hz Capacitance - pf Voltage - Vdet iil3_ iil3_ Figure. Amplitude Response vs. Frequency Figure. Photodiode Junction Capacitance vs. Reverse Voltage Amplitude Response - db iil3_3 CMRR - Rejection Ratio - db iil3_ I Fq = ma Mod= ±. ma T A = C R L = Ω db PHASE F - Frequency - Hz Figure 3. Amplitude and Phase Response vs. Frequency Figure. Common-Mode Rejection Phase Response - -3 F - Frequency - Hz Application Considerations In applications such as monitoring the output voltage from a line powered switch mode power supply, measuring bioelectric signals, interfacing to industrial transducers, or making floating current measurements, a galvanically isolated, DC coupled interface is often essential. The can be used to construct an amplifier that will meet these needs. The eliminates the problems of gain nonlinearity and drift induced by time and temperature, by monitoring LED output flux. A PIN photodiode on the input side is optically coupled to the LED and produces a current directly proportional to flux falling on it. This photocurrent, when coupled to an amplifier, provides the servo signal that controls the LED drive current. The LED flux is also coupled to an output PIN photodiode. The output photodiode current can be directly or amplified to satisfy the needs of succeeding circuits. Isolated Feedback Amplifier The was designed to be the central element of DC coupled isolation amplifiers. Designing the into an amplifier that provides a feedback control signal for a line powered switch mode power is quite simple, as the following example will illustrate. See Figure for the basic structure of the switch mode supply using the Infineon TDA9 Push-Pull Switched Power Supply Control Chip. Line isolation and insulation is provided by the high frequency transformer. The voltage monitor isolation will be provided by the.

9 VISHAY The isolated amplifier provides the PWM control signal which is derived from the output supply voltage. Figure more closely shows the basic function of the amplifier. The control amplifier consists of a voltage divider and a non-inverting unity gain stage. The TDA9 data sheet indicates that an input to the control amplifier is a high quality operational amplifier that typically requires a +3. V signal. Given this information, the amplifier circuit topology shown in Figure is selected. The power supply voltage is scaled by R and R so that there is + 3. V at the non-inverting input (Va) of U. This voltage is offset by the voltage developed by photocurrent flowing through R3. This photocurrent is developed by the optical flux created by current flowing through the LED. Thus as the scaled monitor voltage (Va) varies it will cause a change in the LED current necessary to satisfy the differential voltage needed across R3 at the inverting input. The first step in the design procedure is to select the value of R3 given the LED quiescent current (IFq) and the servo gain (K). For this design, I Fq = ma. Figure shows the servo photocurrent at I Fq is found to be µa. With this data R3 can be calculated. The value of R depends upon the Transfer Gain (K3). K3 is targeted to be a unit gain device, however to minimize the part to part Transfer Gain variation, Infineon offers K3 graded into ± % bins. R can determined using the following equation, R = Or if a unity gain amplifier is being designed (VMON- ITOR = VOUT, R = ), the equation simplifies to: R = V OUT R3(R + R) V MONITOR RK3 R3 K3 9 R3 = V b I PI = 3V µa =3KΩ To Control Input ISO AMP R R Voltage Monitor iil3_ Figure. Isolated Control Amplifier For best input offset compensation at U, R will equal R3. The value of R can easily be calculated from the following. R=R( V MONITOR Va - ) 9

10 VISHAY / MAIN AC/DC RECTIFIER SWITCH XFORMER AC/DC RECTIFIER DC OUTPUT SWITCH MODE REGULATOR TDA9 CONTROL ISOLATED FEEDBACK iil3_ Figure. Switching Mode Power Supply V monitor R KW R 3 KW R3 3 KW Va Vb 3 + V CC R U W LM - V CC 3 pf K K V CC V out R 3 KW To control input iil3_ Table. gives the value of R given the production K3 bins. R Selection Table. Figure. DC Coupled Power Supply Feedback Amplifier Bins Min. Max. 3 Typ. R Resistor KΩ A B C D E F G H I J % KΩ

11 VISHAY The last step in the design is selecting the LED current limiting resistor (R). The output of the operational amplifier is targeted to be % of the V CC, or. V. With an LED quiescent current of ma the typical LED (V F ) is.3 V. Given this and the operational output voltage, R can be calculated. V opamp -V R = F = I Fq. V -.3 V ma = Ω The circuit was constructed with an LM differential operational amplifier using the resistors selected. The amplifier was compensated with a pf capacitor connected between pins and. The DC transfer characteristics are shown in Figure 9. The amplifier was designed to have a gain of. and was measured to be.3. Greater accuracy can be achieved by adding a balancing circuit, and potentiometer in the input divider, or at R. The circuit shows exceptionally good gain linearity with an RMS error of only.33 % over the input voltage range of. V -. V in a servo mode; see Figure. Vout - Output Voltage - V Vout =. mv +.3 x Vin LM Ta = C Linearity Error - % iil3_... Vin - Input Voltage - V Figure. Linearity Error vs. Input Voltage The AC characteristics are also quite impressive offering a - 3. db bandwidth of khz, with a - phase shift at khz as shown in Figure. Amplitude Response - db iil3_ LM db PHASE Figure. Amplitude and Phase Power Supply Control F - Frequency - Hz Phase Response - iil3_9 Figure 9. Transfer Gain The same procedure can be used to design isolation amplifiers that accept bipolar signals referenced to ground. These amplifiers circuit configurations are shown in Figure. In order for the amplifier to respond to a signal that swings above and below ground, the LED must be pre biased from a separate source by using a voltage reference source (V ref ). In these designs, R3 can be determined by the following equation. R3 = V ref I P = V ref KI Fq 9

12 VISHAY Non-Inverting Input Non-Inverting Output Vin R 3 + Vcc R Vcc pf R3 Vref Vcc Ω +Vcc 3 IL 3 Vcc +Vref R R Vcc 3 + R Vo Vcc Inverting Input Inverting Output Vin R iil3_ 3 + Vcc R Vcc R3 +Vref Ω +Vcc pf 3 Vcc IL 3 +Vref 3 + Vcc Vcc Vcc R Vout Figure. Non-inverting and Inverting Amplifiers Table. Optolinear amplifiers Amplifier Input Output Gain Offset Non-Inverting Inverting Non-Inverting Inverting Non-Inverting V OUT V IN = K3 R R R3 (R + R) V OUT K3 R R (R + R) = V IN R3 R (R + R) V ref V ref = V ref R K3 R3 = -V ref R (R + R) K3 R3 R Inverting Inverting Non-Inverting Non-Inverting Inverting V OUT V IN V OUT V IN = = -K3RR(R+R) R3 R (R + R) - K3 R R R3 (R + R) V ref V ref = V ref R (R + R) K3 R3 R = -V ref R K3 R3 9 These amplifiers provide either an inverting or noninverting transfer gain based upon the type of input and output amplifier. Table shows the various configurations along with the specific transfer gain equations. The offset column refers to the calculation of the output offset or V ref necessary to provide a zero voltage output for a zero voltage input. The non-inverting input amplifier requires the use of a bipolar supply, while the inverting input stage can be implemented with single supply operational amplifiers that permit operation close to ground.

13 VISHAY For best results, place a buffer transistor between the LED and output of the operational amplifier when a CMOS opamp is used or the LED I Fq drive is targeted to operate beyond ma. Finally the bandwidth is influenced by the magnitude of the closed loop gain of the input and output amplifiers. Best bandwidths result when the amplifier gain is designed for unity. Package Dimensions in Inches (mm). (.).3 (.9). (.). (. ). (.).33 (.3) Pin ID..3 (3.3). (.9). (3.). (.). (.). (. ) 3.3 (9.). (.). (.) REF..3 Typ. (.) Typ.. (.) REF.. (.). (.). (.) REF. 3 9 ISO Method A i. (.3). (.3). (.9).3 (3.3) Option Option Option 9. (.3).39 (9.9).3 (.).9 (.). (.3). (.). (.).3 (.9). (.) MIN..3 (.) TYP..3 (.) MIN..33 (.) MIN.. (.3) MAX.. (.). (.). (.).9 (.9).3 (9.3).39 (.3).3 (.) ref.. (.). (.).3 (.) min.. (.3) typ. max. 3

14 VISHAY Ozone Depleting Substances Policy Statement It is the policy of Vishay Semiconductor GmbH to. Meet all present and future national and international statutory requirements.. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances (ODSs). The Montreal Protocol (9) and its London Amendments (99) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. Vishay Semiconductor GmbH has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents.. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively. Class I and II ozone depleting substances in the Clean Air Act Amendments of 99 by the Environmental Protection Agency (EPA) in the USA 3. Council Decision //EEC and 9/9/EEC Annex A, B and C (transitional substances) respectively. Vishay Semiconductor GmbH can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use products for any unintended or unauthorized application, the buyer shall indemnify against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. Vishay Semiconductor GmbH, P.O.B. 33, D- Heilbronn, Germany

15 Legal Disclaimer Notice Vishay Disclaimer All product specifications and data are subject to change without notice. Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively, Vishay ), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any information provided herein to the maximum extent permitted by law. The product specifications do not expand or otherwise modify Vishay s terms and conditions of purchase, including but not limited to the warranty expressed therein, which apply to these products. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document or by any conduct of Vishay. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding products designed for such applications. Product names and markings noted herein may be trademarks of their respective owners. Document Number: 9 Revision: -Jul-

Dimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit.

Dimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit. IL Linear Optocoupler Dimensions in inches (mm) FEATURES Couples AC and DC signals.% Servo Linearity Wide Bandwidth, > khz High Gain Stability, ±.%/C Low Input-Output Capacitance Low Power Consumption,