FOD2741A

OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A DESCRIPTION The FOD2741 Optically Isolated Amplifier consists of the popular KA431 precision programmable shunt reference and an optocoupler. The optocoupler is a gallium arsenide (GaAs) light emitting diode optically coupled to a silicon phototransistor. It comes in 3 grades of reference voltage tolerance = 2%, 1%, and 0.5%. The Current Transfer Ratio (CTR) ranges from 100% to 200%. It also has an outstanding temperature coefficient of 50 ppm/°C. 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. When using the FOD2741, 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. The device comes in a 8-pin dip white package. 8 1 8 1 8 1 FOD2741B FOD2741C FEATURES • • • • • Optocoupler, precision reference and error amplifier in single package 2.5V reference CTR 100% to 200% 5,000V RMS isolation UL approved E90700, Volume 2 CSA approval 1296837 VDE approval 40002463 BSI approval 8702, 8703 • Low temperature coefficient 50 ppm/°C max • FOD2741A: tolerance 0.5% FOD2741B: tolerance 1% FOD2741C: tolerance 2% FUNCTIONAL BLOCK DIAGRAM NC 1 8 LED C 2 7 FB E 3 6 COMP NC 4 5 GND APPLICATIONS • Power supplies regulation • DC to DC converters PIN DEFINITIONS Pin Number 1 2 3 4 5 6 7 8 Pin Name NC C E NC GND COMP FB LED Pin function description Not connected Phototransistor Collector Phototransistor Emitter Not connected Ground Error Amplifier Compensation. This pin is the output of the error amplifier. * Voltage Feedback. This pin is the inverting input to the error amplifier Anode LED. This pin is the input to the light emitting diode. * The compensation network must be attached between pins 6 and 7. © 2003 Fairchild Semiconductor Corporation Page 1 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A TYPICAL APPLICATION FOD2741B FOD2741C V1 FAN4803 PWM Control VO FOD2741 2 8 6 R1 3 7 R2 5 ABSOLUTE MAXIMUM RATINGS (TA = 25°C Unless otherwise specified.) Parameter Storage Temperature Operating Temperature Lead Solder Temperature Input Voltage Input DC Current Collector-Emitter Voltage Emitter-Collector Voltage Collector Current Input Power Dissipation (note 1) Transistor Power Dissipation (note 2) Total Power Dissipation (note 3) Symbol TSTG TOPR TSOL VLED ILED VCEO VECO IC PD1 PD2 PD3 Value -55 to +125 -25 to +85 260 for 10 sec. 37 20 30 7 50 145 85 145 Units °C °C °C V mA V V mA mW mW mW Notes 1. Derate linearly from 25°C at a rate of 2.42 mW/ °C 2. Derate linearly from 25°C at a rate of 1.42 mW/ °C. 3. Derate linearly from 25°C 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. © 2003 Fairchild Semiconductor Corporation Page 2 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A FOD2741B FOD2741C ELECTRICAL CHARACTERISTICS (TA = 25°C Unless otherwise specified.) INPUT CHARACTERISTICS Parameter LED Forward Voltage Test Conditions (ILED = 10 mA, VCOMP = VFB) (fig.1) ILED = 10 mA, VCOMP = VFB Symbol VF VREF Device ALL A Reference Voltage Deviation of VREF over temperature Ratio of VREF variation to the output of the error amplifier Feedback Input Current Deviation of IREF over temperature Minimum Drive Current Off-state error amplifier current Error amplifier output impedance (see note 2) ILED = 10 mA B C TA = -25°C to +85°C VREF (DEV) ∆VCOMP = 10V to VREF ∆VCOMP = 36V to 10V ∆VREF/ ∆VCOMP IREF IREF (DEV) ILED (MIN) I(OFF) |ZOUT| ALL ALL ALL ALL ALL ALL ALL 2.482 2.470 2.450 2.495 2.495 2.500 4.5 -1.0 -0.5 1.5 0.4 0.45 0.05 0.15 Min. Typ. Max. 1.5 2.508 2.520 2.550 17 -2.7 -2.0 4 1.2 1.0 1.0 0.5 Unit V V V V mV mV/ V µA µA mA µA Ω ILED = 10mA, R1 = 10kΩ (fig 3) TA = -25°C to +85°C VCOMP = VFB (fig.1) VLED = 37V, VFB = 0 (fig 4.) VCOMP = VREF, ILED = 1mA to 20mA, f ≥ 1.0 kHz 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: { V REF ( DEV ) /V REF ( T A = 25 °C ) } × 10 ∆ V REF ( ppm/°C ) = ---------------------------------------------------------------------------------------------------∆ 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: ∆V R1 Z OUT, TOT = ------- ≈ Z OUT × 1 + ------∆I R2 6 © 2003 Fairchild Semiconductor Corporation Page 3 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A FOD2741B FOD2741C OUTPUT CHARACTERISTICS (TA = 25°C Unless otherwise specified.) Parameter Collector dark current Emitter-collector voltage breakdown Collector-emitter voltage breakdown Test Conditions (VCE = 10 V) (Fig. 5) (IE = 100 µA) (IC = 1.0mA) Symbol ICEO BVECO BVCEO 7 70 Min Typ Max 50 Unit nA V V TRANSFER CHARACTERISTICS (TA = 25°C Unless otherwise specified.) Parameter Current transfer ratio Collector-emitter saturation voltage Test Conditions (ILED = 10 mA, VCOMP = VFB, VCE = 5 V) (Fig. 6) Symbol CTR Min 100 Typ Max 200 0.4 Unit % V (ILED = 10 mA, VCOMP = VFB, VCE (SAT) IC = 2.5 mA) (Fig. 6) ISOLATION CHARACTERISTICS (TA = 25°C Unless otherwise specified.) Parameter Input-output insulation leakage current Withstand insulation voltage Resistance (input to output) Test Conditions (RH = 45%, TA = 25°C, t = 5s, VI-O = 3000 VDC) (note. 1) (RH 6.25k Ω ; R COLLECTOR select 12kΩ to allow some margin. Feedback Output voltage of a converter is determined by selecting a resistor divider from the regulated output to the FB pin. The FOD2741 attempts to regulate its FB pin to the reference voltage, 2.5V. The ratio of the two resistors should thus be: R TOP V OUT ------------------------- = -------------- – 1 R BOTTOM V REF The absolute value of the top resistor is set by the input offset current of 5.2µA. To achieve 0.5% accuracy, the resistance of RTOP should be: V OUT – 2.5 ---------------------------- > 1040 µ A R TOP © 2003 Fairchild Semiconductor Corporation Page 10 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A FOD2741B FOD2741C Package Dimensions (Through Hole) Package Dimensions (Surface Mount) 0.390 (9.91) 0.370 (9.40) 4 3 2 1 PIN 1 ID. 4 3 2 1 PIN 1 ID. 0.270 (6.86) 0.250 (6.35) 5 6 7 8 0.270 (6.86) 0.250 (6.35) 5 6 7 8 0.390 (9.91) 0.370 (9.40) SEATING PLANE 0.070 (1.78) 0.045 (1.14) 0.200 (5.08) 0.140 (3.55) 0.020 (0.51) MIN 0.070 (1.78) 0.045 (1.14) 0.020 (0.51) MIN 0.300 (7.62) TYP 0.016 (0.41) 0.008 (0.20) 0.154 (3.90) 0.120 (3.05) 0.022 (0.56) 0.016 (0.41) 0.100 (2.54) TYP 0.016 (0.40) 0.008 (0.20) 15° MAX 0.300 (7.62) TYP 0.022 (0.56) 0.016 (0.41) 0.100 (2.54) TYP Lead Coplanarity : 0.004 (0.10) MAX 0.045 [1.14] 0.315 (8.00) MIN 0.405 (10.30) MIN Package Dimensions (0.4"Lead Spacing) 8 - Pin Dip 4 3 2 1 PIN 1 ID. 0.070 (1.78) 0.270 (6.86) 0.250 (6.35) 0.060 (1.52) 5 6 7 8 0.390 (9.91) 0.370 (9.40) 0.100 (2.54) 0.295 (7.49) 0.070 (1.78) 0.045 (1.14) SEATING PLANE 0.415 (10.54) 0.030 (0.76) 0.200 (5.08) 0.140 (3.55) 0.004 (0.10) MIN 0.154 (3.90) 0.120 (3.05) 0.022 (0.56) 0.016 (0.41) 0.100 (2.54) TYP 0.016 (0.40) 0.008 (0.20) 0° to 15° 0.400 (10.16) TYP NOTE All dimensions are in inches (millimeters) © 2003 Fairchild Semiconductor Corporation Page 11 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A ORDERING INFORMATION Example: FOD2741A X FOD2741B Y Y V: VDE tested FOD2741C X Packaging Option T: 0.4” Lead Spacing S: Surface Mount Lead Bend SD: Surface Mount Tape and Reel (1000 per reel) MARKING INFORMATION 1 2741A V 3 4 2 6 XX YY B 5 Definitions 1 2 3 4 5 6 Fairchild logo Device number VDE mark (Note: Only appears on parts ordered with VDE option – See order entry table) Two digit year code, e.g., ‘03’ Two digit work week ranging from ‘01’ to ‘53’ Assembly package code © 2003 Fairchild Semiconductor Corporation Page 12 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A Carrier Tape Specifications FOD2741B FOD2741C K0 t P0 P2 D0 E A0 W1 B0 F W d User Direction of Feed P D1 Description Tape Width Tape Thickness Sprocket Hole Pitch Sprocket Hole Diameter Sprocket Hole Location Pocket Location Pocket Pitch Pocket Dimensions Cover Tape Width Cover Tape Thickness Max. Component Rotation or Tilt Min. Bending Radius Symbol W t P0 D0 E F P2 P A0 B0 K0 W1 d R Dimension in mm 16.0 ± 0.3 0.30 ± 0.05 4.0 ± 0.1 1.55 ± 0.05 1.75 ± 0.10 7.5 ± 0.1 4.0 ± 0.1 12.0 ± 0.1 10.30 ±0.20 10.30 ±0.20 4.90 ±0.20 1.6 ± 0.1 0.1 max 10° 30 © 2003 Fairchild Semiconductor Corporation Page 13 of 15 12/9/04 OPTICALLY ISOLATED ERROR AMPLIFIER FOD2741A Reflow Profile FOD2741B FOD2741C 300 Temperature (°C) 250 200 150 100 50 0 0 0.5 1 1.5 2 2.5 260 C peak 245 C, 10–30 s Time above 183C,