LIA120 Optically Isolated Linear Error Amplifier INTEGRATED CIRCUITS DIVISION Features Description Optocoupler, precision reference and error amplifier The LIA120 Optically Isolated Reference Amplifier in single package combines IXYS IC Divisions linear optical coupler Low voltage operation 2.7V technology with an industry standard 431 type 1.240V 2.5% reference precision programmable shunt regulator to provide CTR Matching 15% very linear high gain with excellent temperature >70dB THD stability for a total gain error of less than 2dB. By using 70dB CMRR optical feedback, the LIA120 essentially eliminates 3,750V isolation temperature and gain variations due to current rms transfer ratio (CTR) changes in optocouplers while increasing the bandwidth up to 10X and easing Applications engineering design constraints. Power supply feedback Telecom central office supply The LIA120 is very well suited for high gain feedback Telecom bricks amplifiers that require excellent linearity and low Modem transformer replacement temperature variation such as isolated power Digital telephone isolation supply feedback stages, modem audio transformer replacement, isolated industrial control signals, and sensor feedback. Block Diagram By using the LIA120, system designers can save precious board space and reduce component count. Available in an 8-pin surface mount package. NC LED (Input) 1 8 Approvals K 2 7 COMP UL 1577 Recognized Component: File E76270 A 3 6 FB Ordering Information NC GND 4 5 Part Description LIA120S 8-Pin Surface Mount, Tubed (50/Tube) LIA120STR 8-Pin Surface Mount, Tape and Reel (1000/Reel) DS-LIA120-R04 1 www.ixysic.comLIA120 INTEGRATED CIRCUITS DIVISION Absolute Maximum Ratings ( 25C) Absolute Maximum Ratings are stress ratings. Stresses in Parameter Symbol Ratings Units excess of these ratings can cause permanent damage to Photodiode Cathode-Anode Voltage V 20 V KAO the device. Functional operation of the device at conditions Photodiode Anode-Cathode Voltage V 0.5 V AKO beyond those indicated in the operational sections of this Input Voltage V 9V LED data sheet is not implied. Input DC Current I 20 mA LED Total Power Dissipation (note 1) P 145 mW D Operating Temperature T -40 to +85 C Storage Temperature T -40 to +125 C 1 Derate linearly from 25C at a rate of 2.42 mW/ C. Electrical Characteristics: Parameter Conditions Symbol Min Typ Max Units Input Characteristics 25C LED forward voltage I = 5 mA, V = V (Fig.1) V 0.8 1.2 1.4 V LED COMP FB F Reference voltage I = 10 mA, V = V (Fig.1) LED COMP FB T = -40 to +85C 1.210 - 1.265 A V V REF T = 25C 1.228 1.24 1.252 A Deviation of V over temperature - See Note 1 T = -40 to +85C V -32 - mV REF A REF (DEV) Transfer Characteristics 25C Current Transfer Ratio in Feedback (I /I)I = 5mA, V = 0.5V (Fig.2) K 1.0 2 3.0 % REF LED LED REF 1 Current transfer ratio (I /I)I = 5 mA, V = V , V = 5 V (Fig. 4) K 1.0 2 3.0 % KA LED LED COMP FB KA 2 Current Transfer Ratio Matching (I /I)I = 5mA, V = 5.0V K 85 100 115 % KA REF LED KA 3 Feedback input current I = 10 mA, R1 = 10 k (Fig.2) I - 226 - A LED REF Deviation of I over temperature - See Note 1 T = -40 to +85C I - 110 - A REF A REF (DEV) Minimum drive current V = V (Fig.1) I 1- - mA COMP FB LED (MIN) Off-state error amplifier current V = 6 V, V = 0 (Fig.3) I - 0.001 0.1 A IN FB OFF Error amplifier output impedance - See Note 2 I = 0.1 mA to 15 mA, V = V , f<1 kHz (Fig.1) IZ I - 0.21 - LED COMP FB OUT Output Characteristics 25C Cathode dark current V = Open, V = 10V (Fig. 3) I - 0.3 100 nA IN KA KAO Cathode-Anode voltage breakdown I = 1A BV 20 - - V KA KA Isolation Characteristics 25C Withstand insulation voltage RH 50%, T = 25C, t = 1 min (Note 3) V 3750 - - V A ISO rms 12 Resistance (input to output) V = 500 V (Note 3) R -10 - I-O DC I-O AC Characteristics 25C Bandwidth (LED) - See Note 4 -B - 100 - kHz W Common mode rejection ratio - See Note 5 I = 1.0 mA, R =100 k, f=100 Hz (Fig. 5) CMRR - 70 - dB LED L Linearity I = 5 mA, 100 mV THD - 70 - dB LED PP 1. The deviation parameters V and I are defined as the differences between the maximum and minimum values obtained over the rated temperature range. The average REF(DEV) REF(DEV) full-range temperature coefficient of the reference input voltage, V , is defined as: REF 6 V (ppm/C) = V /V (T 25C) X 10 / T REF REF (DEV) REF A A where T is the rated operating free-air temperature range of the device. A 2. The dynamic impedance is defined as Z = V /I , for the application circuit in Figure 6, Zout = K R OUT COMP LED 1 1 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. See compensation section for calculating bandwidth of LIA120. 5. 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. R04 2 www.ixysic.com