LIA130 Optically Isolated Error Amplifier Features * Optocoupler, precision reference and error amplifier in single package * 1.240V 1% reference * CTR 300% to 600% * 3,750Vrms isolation * VDE approval 136616 * BSI approval 8661 and 8662 * UL approval E90700 * CSA approval 1113643 Description The LIA130 Optically Isolated Amplifier consists of the popular IX431 precision programmable shunt reference and an optocoupler. The optocoupler is a gallium arsenide (GaAs) light emitting diode optically coupled to a silicon phototransistor. The reference voltage tolerance is 1%. The current transfer ratio (CTR) ranges from 300% to 600%. Applications * Power system for workstations * Telecom central office supply * Telecom bricks When using the LIA130, power supply designers can reduce the component count and save space in tightly packaged designs. The tight tolerance reference eliminates the need for adjustments in many applications. IN A R Y It is primarily intended for use as the error amplifier/ reference voltage/optocoupler function in isolated ac to dc power supplies and dc/dc converters. The device comes in a compact 8-pin small outline package. C 2 E 3 NC 4 8 LED Part # LIA130 Description 8 Pin Surface Mount EL 1 Ordering Information 7 FB 6 COMP 5 GND PR NC IM Block Diagram DS-LIA130-R00A.4 www.clare.com 1 LIA130 Absolute Maximum Ratings (@ 25 C) Absolute Maximum Ratings are stress ratings. Stresses in excess of these ratings can cause permanent damage to the device. Functional operation of the device at conditions beyond those indicated in the operational sections of this data sheet is not implied. Y Parameter Symbol Ratings Units Storage Temperature TSTG -55 to +125 C TOPR -40 to +85 C Operating Temperature Reflow Temperature Profile Input Voltage VLED 10 V Input DC Current ILED 20 mA Collector-Emitter Voltage VCEO 20 V VECO 7 V Emitter-Collector Voltage Collector Current IC 50 mA PD1 145 mW Input Power Dissipation (note 1) Transistor Power Dissipation (note 2) PD2 85 mW Total Power Dissipation (note 3) PD3 145 mW 1 R Derate linearly from 25C at a rate of 2.42 mW/ C. Derate linearly from 25C at a rate of 1.42 mW/ C. 3 Derate linearly from 25C at a rate of 2.42 mW/ C. 4 Functional operation under these conditions is not implied. Permanent damage may occur if the device is subjected to conditions outside these ratings. A 2 Electrical Characteristics: Relay PR EL IM IN Parameter Conditions Symbol Input Characteristics @ 25C LED forward voltage (ILED = 5 mA, VCOMP = VFB)(Fig.1) VF Reference voltage (-40 to +85C) (VCOMP = VFB, ILED = 10 mA (Fig.1) VREF (25C) Deviation of VREF over temperature - See Note 1 (TA = -40 to +85C) VREF (DEV) VREF/ Ratio of Vref variation to the output of the (ILED = 10 mA, VCOMP = VREF to 10 V) (Fig.2) error amplifier VCOMP IREF Feedback input current (ILED = 10 mA, R1 = 10 k) (Fig.3) Deviation of IREF over temperature - See Note 1 (TA = -40 to +85C) IREF (DEV) ILED (MIN) Minimum drive current (VCOMP = VFB) (Fig.1) Off-state error amplifier current (VLED = 6 V, VFB = 0) (Fig.4) I (OFF) (VCOMP = VFB, ILED = 0.1 mA to 15 mA, f<1 kHZ) IZOUTI Error amplifier output impedance - See Note 2 Output Characteristics @ 25C Collector dark current (VCE = 10V) (Fig. 5) ICEO BVCEO Collector-emitter voltage breakdown (IC = 1.0mA) Emitter-collector voltage breakdown (IE = 100 A) BVECO Min Typ Max Units - - 1.4 V TBD TBD - 1.24 77 TBD TBD TBD mV - 0.002 TBD mV/V - 0.09 0.028 45 0.001 0.22 TBD TBD 80 0.1 - A A A A Ohm 20 7 0.3 - TBD - nA V V V 1. The deviation parameters VREF(DEV) and IREF(DEV) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. The average full-range temperature coefficient of the reference input voltage, VREF, is defined as: |VREF| (ppm/C) = {VREF (DEV)/VREF (TA 25C)} X 106 / TA where TA is the rated operating free-air temperature range of the device. 2. The dynamic impedance is defined as |ZOUT| = VCOMP/ILED. When the device is operating with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by: |ZOUT, TOT| = V/I |ZOUT| X [1 + R1/R2] 3. Device is considered as a two terminal device: Pins 1, 2, 3 and 4 are shorted together and Pins 5, 6, 7 and 8 are shorted together. 4. Common mode transient immunity at output high is the maximum tolerable (positive) dVcm/dt on the leading edge of the common mode impulse signal, Vcm, to assure that the output will remain high. Common mode transient immunity at output low is the maximum tolerable (negative) dVcm/dt on the trailing edge of the common pulse signal,Vcm, to assure that the output will remain low. 2 www.clare.com R00A.4 LIA130 Electrical Characteristics: Relay Withstand insulation voltage Resistance (input to output) Switching Characteristics @ 25C Bandwidth Common mode transient immunity at output high Common mode transient immunity at output low Symbol Min Typ Max Units (ILED = 5 mA, VCOMP = VFB, VCE = 5 V) (Fig. 6) (ILED = 10 mA, VCOMP = VFB, IC = 2.5 mA) (Fig. 6) CTR VCE (SAT) - 500 0.099 600 0.5 % V (RH = 45%, TA = 25C, t = 5s, VI-O = 3000 VDC) (note. 3) (RH <= 50%, TA = 25C, t = 1 min) (notes. 3) VI-O = 500 VDC (note. 3) II-O - - 1.0 A VISO RI-O 2500 - 1012 - Vrms (Fig. 7) - 10 - kHZ (ILED = 0 mA, Vcm = 10 VPP RL = 2.2 k (Fig.8) BW |CMH| - TBD - kV/s (ILED = 10 mA, Vcm = 10 VPP RL = 2.2 k |CML| - TBD - kV/s Y Input-output insulation leakage current Conditions (note. 4) (Fig.8) (note. 4) R Parameter Transfer Characteristics @ 25C Current transfer ratio Collector-emitter saturation voltage Isolation Characteristics @ 25C A 1. The deviation parameters VREF(DEV) and IREF(DEV) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. The average full-range temperature coefficient of the reference input voltage, VREF, is defined as: |VREF| (ppm/C) = {VREF (DEV)/VREF (TA 25C)} X 106 / TA where TA is the rated operating free-air temperature range of the device. IN 2. The dynamic impedance is defined as |ZOUT| = VCOMP/ILED. When the device is operating with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by: |ZOUT, TOT| = V/I |ZOUT| X [1 + R1/R2] 3. Device is considered as a two terminal device: Pins 1, 2, 3 and 4 are shorted together and Pins 5, 6, 7 and 8 are shorted together. PR EL IM 4. Common mode transient immunity at output high is the maximum tolerable (positive) dVcm/dt on the leading edge of the common mode impulse signal, Vcm, to assure that the output will remain high. Common mode transient immunity at output low is the maximum tolerable (negative) dVcm/dt on the trailing edge of the common pulse signal,Vcm, to assure that the output will remain low. R00A.4 www.clare.com 3 LIA130 I(LED) I(LED) 8 8 2 2 VF 6 3 7 V R1 6 V 3 7 VREF 5 R 5 Y VCOMP R2 VREF FIG. 2. VREF/VCOMP TEST CIRCUIT I(LED) IREF 2 6 V(LED) 5 PR 6 2 3 5 FIG. 4. I(OFF) TEST CIRCUIT FIG. 3. IREF TEST CIRCUIT 8 2 7 V EL R1 8 6 3 7 V I(OFF) IM 8 IN A FIG. 1. VREF, VF, ILED (min) TEST CIRCUIT I(LED) ICEO 8 VCE VCE 6 3 7 I(C) 2 V 3 7 VCOMP VREF 5 5 FIG. 5. ICEO TEST CIRCUIT 4 FIG. 6. CTR, VCE(sat) TEST CIRCUIT www.clare.com R00A.4 LIA130 VCC = +5V DC IF = 10 mA 1 RL 47 8 1f 3 6 4 5 VIN 0.47V 0.1 VPP Y 7 R 2 A VOUT IM IN Fig. 7 Frequency Response Test Circuit VCC = +5V DC 1 8 2 7 3 6 4 5 EL R1 2.2k IF = 0 mA (A) IF = 10 mA (B) PR VOUT _ VCM A B + 10VP-P Fig. 8 CMH and CML Test Circuit R00A.4 www.clare.com 5 LIA130 PERFORMANCE DATA* 0 -5 -10 1.0 1.5 -0.5 90 80 70 60 0 20 40 80 0.2 0.1 20 10 -20 0 20 40 60 80 20 40 60 0.20 0.15 0.10 0.05 0 20 40 60 80 80 100 0 60 ILED = 10mA 40 ILED = 5mA 20 ILED = 1mA 0 20 20 40 60 80 85C 1.2 1.3 -5C 10 5 0 0.8 0.9 1.0 1.1 1.4 1.5 1.6 VF - Forward-Voltage (V) ILED = 20mA -20 -20 15 100 VCE = 5V -40 -40 40 60 80 100 700 600 LIA130 Current Transfer Ratio vs LED Current VCE = 5V 500 400 300 200 100 0 0 5 10 15 20 25 ILED - Forward Current (mA) LIA130 Collector Current vs. Collector Voltage 180 IC - Collector Current (mA) VCE (sat) - Saturation Voltage (V) 0 80 0 100 0.25 -20 1.28 LIA130 LED Forward Current vs. Forward Voltage 100 0.30 -40 1.31 20 LIA130 Collector Current vs. Ambient Temperature LIA130 Saturation Voltage vs. Ambient Temperature ILED = 10mA; IC = 10mA 0.00 -20 EL 30 -40 -40 120 VCE = 10V 0 VLED = 13.2V VFB = 0 0.3 100 LIA130 Dark Current vs. Temperature 40 -10 60 1.5 1.34 IM -20 1.0 LIA130 Off Current vs. Ambient Temperature 0.4 0 -40 IC - Collector Current (mA) 50 0.5 IN I(OFF) - Off Current (nA) ILED = 10mA R1 = 10 k 100 50 ICEO - Dark Current (nA) 0.5 PR IREF - Reference Current (mA) LIA130 Reference Voltage vs. Ambient Temperature 110 0.0 VCOMP - Cathode Voltage (V) 1.37 R 0.5 (IC/IF) - Current Transfer Ratio (%) 0.0 VCOMP - Cathode Voltage (V) 160 140 120 ILED = 20mA 100 80 ILED = 10mA 60 40 ILED = 5mA 20 ILED = 1mA 0 0 1 2 3 4 5 6 7 8 9 10 VCE (sat) - Saturation Voltage (V) -0.5 A -15 -1.0 ILED = 10mA Y 5 1.40 VREF - Reference Voltage (V) 10 150 120 90 60 30 0 -30 -60 -90 -120 -150 -1.0 ILED - Forward Current (mA) ILED - Supply Current (A) ILED - Supply Current (mA) 15 LIA130 Reference Voltage vs. Ambient Temperature LIA130 LED Current vs. Cathode Voltage 55C 25C LIA130 LED Current vs. Cathode Voltage LIA130 Delta VREF/Delta VCOMP vs. Ambient Temperature -1.5 -2.0 -2.5 -3.0 -40 -20 0 20 40 60 80 100 VCE - Collector-Emitter (V) *The Performance data shown in the graphs above is typical of device performance. For guaranteed parameters not indicated in the written specifications, please contact our application department. 6 www.clare.com R00A.4 LIA130 PERFORMANCE DATA* LIA130 Voltage Gain vs. Frequency 0 -15 -30 10 100 1000 Y Voltage Gain, A(Vo/Vin) dB 15 PR EL IM IN A R Frenquency kHz *The Performance data shown in the graphs above is typical of device performance. For guaranteed parameters not indicated in the written specifications, please contact our application department. R00A.4 www.clare.com 7 LIA130 The LIA130 The LIA130 is an optically isolated error amplifier. It incorporates three of the most common elements necessary to make an isolated power supply, a reference voltage, an error amplifier, and an optocoupler. It is functionally equivalent to the popular IX431 shunt voltage regulator plus the optocoupler. Compensation The compensation pin of the LIA130 provides the opportunity for the designer to design the frequency response of the converter. A compensation network may be placed between the COMP pin and the FB pin. In typical low-bandwidth systems, a 0.1F capacitor may be used. For converters with more stringent requirements, a network should be designed based on measurements of the system's loop. An excellent reference for this process may be found in "Practical Design of Power Supplies" by Ron Lenk, IEEE Press, 1998. Y Powering the Secondary Side The LED pin in the LIA130 powers the secondary side, and in particular provides the current to run the LED. The actual structure of the LIA130 dictates the minimum voltage that can be applied to the LED pin: The error amplifier output has a minimum of the reference voltage, and the LED is in series with that. Minimum voltage applied to the LED pin is thus 1.24V + 1.5V = 2.74V. This voltage can be generated either directly from the output of the converter, or else from a slaved secondary winding. The secondary winding will not affect regulation, as the input to the FB pin may still be taken from the output winding. A R Secondary Ground The GND pin should be connected to the secondary ground of the converter. IN No Connect Pins The NC pins have no internal connection. They should not have any connection to the secondary side, as this may compromise the isolation structure. EL IM The LED pin needs to be fed through a current limiting resistor. The value of the resistor sets the amount of current through the LED, and thus must be carefully selected in conjunction with the selection of the primary side resistor. PR Feedback Output voltage of a converter is determined by selecting a resistor divider from the regulated output to the FB pin. The LIA130 attempts to regulate its FB pin to the reference voltage, 1.24V. The ratio of the two resistors should thus be: The value of the pull-up resistor, and the current limiting resistor feeding the LED, must be carefully selected to account for voltage range accepted by the PWM IC, and for the variation in current transfer ratio (CTR) of the opto-isolator itself. RTOP/RBOTTOM = VOUT/VREF - 1 The absolute value of the top resistor is set by the input offset current of 0.8A. To achieve 1% accuracy, the resistance of RTOP should be: (VOUT - 1.24) / RTOP > 80A Photo-Transistor The Photo-transistor is the output of the LIA130. In a normal configuration the collector will be attached to a pull-up resistor and the emitter grounded. There is no base connection necessary. Example: The voltage feeding the LED pins is +12V, the voltage feeding the collector pull-up is +10V. If we select a 10K resistor for the LED, the maximum current the LED can see is (12V-2.74V) /10K = 926A. The CTR of the opto-isolator is a minimum of 100%, and so the minimum collector current of the photo-transistor when the diode is full on is also 926A. The collector resistor must thus be such that: (10V - 5V) / RCOLLECTOR < 926A or RCOLLECTOR >5.4K select 10K to allow some margin. 8 www.clare.com R00A.4 Y R A IN IM EL PR For additional information please visit our website at: www.clare.com Clare, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication and reserves the right to make changes to specifications and product descriptions at any time without notice. Neither circuit patent licenses nor indemnity are expressed or implied. Except as set forth in Clare's Standard Terms and Conditions of Sale, Clare, Inc. assumes no liability whatsoever, and disclaims any express or implied warranty, relating to its products including, but not limited to, the implied warranty of merchantability, fitness for a particular purpose, or infringement of any intellectual property right. The products described in this document are not designed, intended, authorized or warranted for use as components in systems intended for surgical implant into the body, or in other applications intended to support or sustain life, or where malfunction of Clare's product may result in direct physical harm, injury, or death to a person or severe property or environmental damage. Clare, Inc. reserves the right to discontinue or make changes to its products at any time without notice. Specification: DS-LIA130-R00A.4 (c)Copyright 2004, Clare, Inc. All rights reserved. Printed in USA. 7/28/04