, High Bandwidth, Analog/Video Optocouplers Data Sheet Description The and optocouplers provide wide bandwidth isolation for analog signals. They are ideal for video isolation when combined with their application circuit (Figure ). High linearity and low phase shift are achieved through an AlGaAs LED combined with a high speed detector. These single channel optocouplers are available in 8 Pin DIP and Widebody package configurations. Functional Diagram NC ANODE CATHODE NC 3 5 8 7 6 V CC V B V O GND Functional Diagram Features Wide bandwidth [] : 7 MHz () 9 MHz () High voltage gain [] :. () 3. () Low G V temperature coefficient: -.3%/ C Highly linear at low drive currents High-speed AlGaAs emitter Safety approval: UL ecognized 375 V rms for minute (5 V rms for minute for # and ) per UL 577 CSA Approved IEC/EN/DIN EN 677-5- Approved V IOM = V peak for Available in 8-pin DIP and widebody packages Applications Video isolation for the following standards/formats: NTSC, PAL, SECAM, S-VHS, ANALOG GB Low drive current feedback element in switching power supplies, e.g., for ISDN networks A/D converter signal isolation Analog signal ground isolation High voltage insulation CAUTION: It is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and/or degradation which may be induced by ESD.
Selection Guide Single Channel Packages 8-Pin DIP Widebody (3 Mil) ( Mil) Ordering Information is UL ecognized with 375 Vrms for minute per UL577 unless otherwise specified. is UL ecognized with 5 Vrms for minute per UL577. Option Part ohs non ohs Surface Gull Tape UL 5 Vrms/ IEC/EN/DIN Number Compliant Compliant Package Mount Wing & eel Minute rating EN 677-5- Quantity -E no option 3 mil DIP-8 5 per tube -3E #3 X X 5 per tube -5E #5 X X X per reel -E # X 5 per tube -3E #3 X X X 5 per tube -5E #5 X X X X per reel -6E #6 X [] 5 per tube -E no option mil X X [] per tube -3E #3 Widebody X X X X [] per tube -5E #5 DIP-8 X X X X X [] 75 per reel Notes:. IEC/EN/DIN EN 677-5- V IOM = 63 V peak Safety Approval.. IEC/EN/DIN EN 677-5- V IOM = V peak Safety Approval. To order, choose a part number from the part number column and combine with the desired option from the option column to form an order entry. Example : -5E to order product of Gull Wing Surface Mount package in Tape and eel packaging with UL 5 Vrms/ minute rating and ohs compliant. Example : to order product of 8-Pin Widebody DIP package in Tube packaging with IEC/EN/DIN EN 677-5- V IOM = V peak Safety Approval and UL 5 Vrms/ minute rating and non ohs compliant. Option datasheets are available. Contact your Avago sales representative or authorized distributor for information. emarks: The notation #XXX is used for existing products, while (new) products launched since July 5, and ohs compliant will use XXXE. Schematic ANODE + V F CATHODE 3 I CC 8 V CC I F I B 7 V B Schematic I O 6 V O 5 GND
U Package Outline Drawings 8-Pin DIP Package () 9.65 ±.5 (.38 ±.) 7.6 ±.5 (.3 ±.) TYPE NUMBE 8 7 A XXXXZ 6 5 OPTION CODE* DATE CODE 6.35 ±.5 (.5 ±.) YYWW 3 UL ECOGNITION.9 (.7) MAX. 3.56 ±.3 (. ±.5).78 (.7) MAX..7 (.85) MAX. 5 TYP..5 +.76 -.5 (. +.3) -.).9 (.5) MIN..5 (.) MIN..8 ±.3 (.3 ±.3).65 (.5) MAX..5 ±.5 (. ±.) DIMENSIONS IN MILLIMETES AND (INCHES). * MAKING CODE LETTE FO OPTION NUMBES "L" = OPTION OPTION NUMBES 3 AND 5 NOT MAKED. NOTE: FLOATING LEAD POTUSION IS.5 mm ( mils) MAX. 8-Pin DIP Package with Gull Wing Surface Mount Option 3 () LAND PATTEN ECOMMENDATION 9.65 ±.5 (.38 ±.).6 (.) 8 7 6 5 6.35 ±.5 (.5 ±.).9 (.3) 3.7 (.5). (.8).9 (.7) MAX..78 (.7) MAX. 3.56 ±.3 (. ±.5) 9.65 ±.5 (.38 ±.) 7.6 ±.5 (.3 ±.).5 +.76 -.5 (. +.3) -.).8 ±.3 (.3 ±.3).5.635 ±.3 (.) (.5 ±.5) BSC DIMENSIONS IN MILLIMETES (INCHES). LEAD COPLANAITY =. mm (. INCHES)..635 ±.5 (.5 ±.) NOM. NOTE: FLOATING LEAD POTUSION IS.5 mm ( mils) MAX. 3
8-Pin Widebody DIP Package () 8.5 ±.5 (. ±.6) 7 6 A HCNWXXXX YYWW 5 TYPE NUMBE DATE CODE. MAX. (.33) 9. ±.5 (.35 ±.6) 3.55 (.6) MAX. 7 TYP. 5. (.) MAX..6 (.) TYP..5 +.76 -.5 (. +.3) -.) 3. (.) 3.9 (.5).5 (.) MIN..5 (.) TYP..78 ±.5 (.7 ±.6). (.6).56 (.) DIMENSIONS IN MILLIMETES (INCHES). NOTE: FLOATING LEAD POTUSION IS.5 mm ( mils) MAX. 8-Pin Widebody DIP Package with Gull Wing Surface Mount Option 3 ().5 ±.5 (. ±.6) LAND PATTEN ECOMMENDATION 8 7 6 5 9. ±.5 (.35 ±.6) 3.56 (.53) 3.3 (.5).9 (.9).55 (.6) MAX..3 ±.3 (.8 ±.). MAX. (.33). (.58) MAX..78 ±.5 (.7 ±.6).5 (.) BSC DIMENSIONS IN MILLIMETES (INCHES)..75 ±.5 (.3 ±.) LEAD COPLANAITY =. mm (. INCHES).. ±.5 (.39 ±.6) 7 NOM..5 +.76 -.5 (. +.3) -.) NOTE: FLOATING LEAD POTUSION IS.5 mm ( mils) MAX.
Solder eflow Temperature Profile TEMPEATUE ( C) 3 PEHEATING ATE 3 C + C/.5 C/SEC. EFLOW HEATING ATE.5 C ±.5 C/SEC. 6 C 5 C C 3 C + C/.5 C.5 C ±.5 C/SEC. PEHEATING TIME 5 C, 9 + 3 SEC. PEAK TEMP. 5 C 3 SEC. 3 SEC. 5 SEC. PEAK TEMP. C SOLDEING TIME C PEAK TEMP. 3 C OOM TEMPEATUE 5 5 5 TIME (SECONDS) TIGHT TYPICAL LOOSE Note: Non-halide flux should be used. ecommended Pb-Free I Profile TEMPEATUE T p * 6 +/-5 C T L 7 C AMP-UP 3 C/SEC. MAX. T smax 5 - C T smin t s PEHEAT 6 to 8 SEC. t p t L TIME WITHIN 5 C of ACTUAL PEAK TEMPEATUE - SEC. AMP-DOWN 6 C/SEC. MAX. 6 to 5 SEC. 5 t 5 C to PEAK TIME NOTES: THE TIME FOM 5 C to PEAK TEMPEATUE = 8 MINUTES MAX. T smax = C, T smin = 5 C Note: Non-halide flux should be used. * ecommended peak temperature for widebody mils package is 5 C egulatory Information The devices contained in this data sheet have been approved by the following organizations: UL ecognized under UL 577, Component ecognition Program, File E5536. CSA Approved under CSA Component Acceptance Notice #5, File CA 883. IEC/EN/DIN EN 677-5- Approved under: IEC 677-5-:997 + A: EN 677-5-: + A: DIN EN 677-5- (VDE 88 Teil ):3- ( only) 5
Insulation and Safety elated Specifications 8-Pin DIP Widebody (3 Mil) ( Mil) Parameter Symbol Value Value Units Conditions Minimum External L() 7. 9.6 mm Measured from input terminals to Air Gap (External output terminals, shortest distance Clearance) through air. Minimum External L() 7.. mm Measured from input terminals to Tracking (External output terminals, shortest distance Creepage) path along body. Minimum Internal.8. mm Through insulation distance, Plastic Gap conductor to conductor, usually the (Internal Clearance) direct distance between the photoemitter and photodetector inside the optocoupler cavity. Minimum Internal NA. mm Measured from input terminals to Tracking (Internal output terminals, along internal cavity. Creepage) Tracking esistance CTI Volts DIN IEC /VDE 33 Part (Comparative Tracking Index) Isolation Group IIIa IIIa Material Group (DIN VDE, /89, Table ) Option 3 - surface mount classification is Class A in accordance with CECC 8. IEC/EN/DIN EN 677-5- Insulation elated Characteristics ( ONLY) 6 Description Symbol Characteristic Units Installation classification per DIN VDE /.89, Table for rated mains voltage 6 V rms for rated mains voltage V rms Climatic Classification 55/85/ Pollution Degree (DIN VDE /.89) Maximum Working Insulation Voltage V IOM V peak Input to Output Test Voltage, Method b* V IOM x.875 = V P, % Production Test with t m = sec, V P 65 V peak Partial Discharge < 5 pc Input to Output Test Voltage, Method a* V IOM x.5 = V P, Type and sample test, V P V peak t m = 6 sec, Partial Discharge < 5 pc Highest Allowable Overvoltage* (Transient Overvoltage, t ini = sec) V IOTM 8 V peak Safety Limiting Values (Maximum values allowed in the event of a failure, also see Figure 7, Thermal Derating curve.) Case Temperature T S 5 C Input Current I S,INPUT ma Output Power P S,OUTPUT 7 mw Insulation esistance at T S, V IO = 5 V S 9 Ω *efer to the front of the optocoupler section of the current catalog, under Product Safety egulations section IEC/EN/DIN EN 677-5-, for a detailed description. Note: Isolation characteristics are guaranteed only within the safety maximum ratings which must be ensured by protective circuits in application. I-IV I-III
Absolute Maximum atings Parameter Symbol Device Min. Max. Units Note Storage Temperature T S -55 5 C Operating Temperature T A - 85 C Average Forward Input Current I F(avg) ma 5 Peak Forward Input Current I F(PEAK) 8.6 ma Effective Input Current I F(EFF).9 ma rms everse LED Input Voltage (Pin 3-) V.8 V 3 Input Power Dissipation P IN mw Average Output Current (Pin 6) I O(AVG) 8 ma Peak Output Current (Pin 6) I O(PEAK) 6 ma Emitter-Base everse Voltage (Pin 5-7) V EB 5 V Supply Voltage (Pin 8-5) V CC -.3 3 V Output Voltage (Pin 6-5) V O -.3 V Base Current (Pin 7) I B 5 ma Output Power Dissipation P O mw Lead Solder Temperature T LS 6 C.6 mm Below Seating Plane, Seconds up to Seating Plane, Seconds 6 C eflow Temperature Profile T P Option See Package Outline 3 Drawings Section ecommended Operating Conditions Parameter Symbol Device Min. Max. Units Note Operating Temperature T A - 7 C Quiescent Input Current I FQ 6 ma Peak Input Current I F(PEAK) ma 7 7
Electrical Specifications (DC) T A = 5 C, I F = 6 ma for and I F = ma for (i.e., ecommended I FQ ) unless otherwise specified. Parameter Symbol Device Min. Typ.* Max. Units Test Conditions Fig. Note Base Photo I PB 3 3 65 µa I F = ma V PB 5 V, 6 Current 9. I F = 6 ma I PB I PB / -.3 %/ C ma < I F < ma, Temperature T V PB 5 V Coefficient I PB.5 % ma < I F < ma, 6 3 Nonlinearity.5 6 ma < I F < ma Input Forward V F..3.6 V I F = 5 ma 5 Voltage..6.8 I F = ma Input everse BV.8 5 V I = µa Breakdown 3 I = µa Voltage Transistor h FE 6 6 I C = ma, Current Gain V CE =.5 V Current CT 5 % V CE =.5 V, 8, 9 Transfer atio 5 V PB 5 V DC Output V OUT.5 V G V =, V CC = 9 V, Voltage 5. 5 8
Small Signal Characteristics (AC) T A = 5 C, I F = 6 ma for and I F = ma for (i.e., ecommended I FO ) unless otherwise specified. Parameter Symbol Device Min. Typ.* Max. Units Test Conditions Fig. Note Voltage Gain G V.8.. V IN = V P-P 6 (. MHz) 3. G V Temperature G V / T -.3 %/ C V IN = V P-P,, Coefficient f EF =. MHz Base Photo i PB. 3. -db V IN = V P-P, 3,, Current (6 MHz).36 f EF =. MHz Variation -3 db Frequency i PB 6 5 MHz V IN = V P-P, 3,, 7 (i PB ) (-3 db) 3 f EF =. MHz -3 db Frequency G V 6 7 MHz V IN = V P-P,, 7 (G V ) (-3 db) 9 f EF =. MHz Gain Variation G V. 3. -db T A = 5 C V IN = V P-P,, (6 MHz).5 f EF =. MHz.8 T A = - C.5 T A = 7 C G V.5 -db V IN = V P-P, ( MHz).7 f EF =. MHz Differential ±. % I Fac =.7 ma p-p, 3, 7 8 Gain at I Fdc = 3 to 9 ma f = 3.58 MHz ±.9 I Fac = ma p-p, I Fdc = 7 to 3 ma Differential ± deg. I Fac =.7 ma p-p, 3, 7 9 Phase at I Fdc = 3 to 9 ma f = 3.58 MHz ±.6 I Fac = ma p-p, I Fdc = 7 to 3 ma Total Harmonic THD.5 % V IN = V P-P, Distortion.75 f = 3.58 MHz, G V = Output Noise V O (noise) 95 µv rms Hz to MHz Voltage Isolation Mode IM db f = Hz, G V = ejection atio 9 9
Package Characteristics All Typicals at T A = 5 C Parameter Sym. Device Min. Typ. Max. Units Test Conditions Fig. Note Input-Output V ISO 375 V rms H 5%, 5, Momentary 5 t = min., 5, 3 Withstand 5 T A = 5 C 5, 3 Voltage* (Option ) Input-Output I-O Ω V I-O = 5 Vdc 5 esistance 3 T A = 5 C T A = C Input-Output C I-O.6 pf f = MHz 5 Capacitance.5.6 *The Input-Output Momentary Withstand Voltage is a dielectric voltage rating that should not be interpreted as an input-output continuous voltage rating. For the continuous voltage rating refer to the VDE 88 Insulation elated Characteristics Table (if applicable), your equipment level safety specification or Avago Application Note 7 entitled Optocoupler Input-Output Endurance Voltage, publication number 5963-3E. Notes:. When used in the circuit of Figure or Figure ; G V = V OUT /V IN ; I FQ = 6 ma (), I FQ = ma ().. Derate linearly above 7 C free-air temperature at a rate of. mw/ C (). 3. Maximum variation from the best fit line of I PB vs. I F expressed as a percentage of the peak-to-peak full scale output.. CUENT TANSFE ATIO (CT) is defined as the ratio of output collector current, I O, to the forward LED input current, I F, times %. 5. Device considered a two-terminal device: Pins,, 3, and shorted together and Pins 5, 6, 7, and 8 shorted together. 6. Flat-band, small-signal voltage gain. 7. The frequency at which the gain is 3 db below the flat-band gain. 8. Differential gain is the change in the small-signal gain of the optocoupler at 3.58 MHz as the bias level is varied over a given range. 9. Differential phase is the change in the small-signal phase response of the optocoupler at 3.58 MHz as the bias level is varied over a given range.. TOTAL HAMONIC DISTOTION (THD) is defined as the square root of the sum of the square of each harmonic distortion component. The THD of the isolated video circuit is measured using a.6 kω load in series with the 5 Ω input impedance of the spectrum analyzer.. ISOLATION MODE EJECTION ATIO (IM), a measure of the optocoupler s ability to reject signals or noise that may exist between input and output terminals, is defined by log [(V OUT /V IN )/(V OUT /V IM )], where V IM is the isolation mode voltage signal.. In accordance with UL 577, each optocoupler is proof tested by applying an insulation test voltage 5 V rms for second (leakage detection current limit, I I-O 5 µa). This test is performed before the % Production test shown in the IEC/EN/DIN EN 677-5- Insulation elated Characteristics Table, if applicable. 3. In accordance with UL 577, each optocoupler is proof tested by applying an insulation test voltage 6 V rms for second (leakage detection current limit, I I-O 5 µa). This test is performed before the % Production test shown in the IEC/EN/DIN EN 677-5- Insulation elated Characteristics Table, if applicable.
6 Ω () 9.9 Ω () Figure. Gain and bandwidth test circuit 6 Ω () 9.9 Ω () Figure. Base photo current test circuit Figure 3. Base photo current frequency response test circuit Figure. ecommended isolated video interface circuit
I F INPUT FOWAD VOLTAGE ma.... I F + V F T A = 7 C...3 T A = - C. V F FOWAD VOLTAGE V.5 Figure 5. Input current vs. forward voltage fig 5a 8 I PB BASE PHOTO CUENT µa 7 6 5 3 V PB > 5 V 6 8 6 8 I F INPUT CUENT ma Figure 6. Base photo current vs. input current fig 6a. SMALL-SIGNAL GAIN.98.96.9.9 NOMALIZED I F = 6 ma f = 3.58 MHz SEE FIG. 3 PHASE GAIN 6 8 6 8 - - -3 SMALL-SIGNAL PHASE DEGEES I F INPUT CUENT ma Figure 7. Small-signal response vs. input current fig 7a
NOMALIZED CUENT TANSFE ATIO....98.96.9.9.9.88.86 - NOMALIZED I F = 6. ma V CE =.5 V V PB > 5 V 3 5 6 7 T TEMPEATUE C Figure 8. Current transfer ratio vs. temperature fig 8a CT NOMALIZED CUENT TANSFE ATIO...9.8.7.6.5 NOMALIZED I F = 6 ma V CE =.5 V V PB > 5 V V CE = 5. V V CE =.5 V V CE =. V 6 8 6 8 I F INPUT CUENT ma Figure 9. Current transfer ratio vs. input current fig 9a i PB BASE PHOTO CUENT VAIATION db -.9 -. -.3 -.5 -.7 -.9 -. -.3 -.5 -.7 FEQUENCY = 6 MHz FEQUENCY = MHz 3 5 6 7 F EF =. MHz 9 I FQ QUIESCENT INPUT CUENT ma 8 Figure. Base photo current variation vs. bias conditions 3 fig a
3 NOMALIZED VOLTAGE GAIN db - - -3 - -5-6 -7... T A = - C T A = 7 C NOMALIZED f =. MHz,, f FEQUENCY KHz Figure. Normalized voltage gain vs. frequency fig a NOMALIZED BASE PHOTO CUENT db.5 -.5 -. -.5 -. -.5-3. -3.5 -. -.5... NOMALIZED f =. MHz,, f FEQUENCY KHz Figure. Normalized base photo current vs. frequency fig a PHASE DEGEES -5-5 -75 - -5-5 -75 - -5-5 6 VIDEO INTEFACE CICUIT PHASE SEE FIGUE 8 I PB PHASE SEE FIGUE 3 6 8 f FEQUENCY MHz Figure 3. Phase vs. frequency fig 3a
IM ISOLATION MODE EJECTION ATIO db 5 9 6 3... - db/decade SLOPE G IM = LOG v v OUT/v IM f FEQUENCY KHz, Figure. Isolation mode rejection ratio vs. frequency fig a 6. V O DC OUTPUT VOLTAGE V 5.5 5..5. 3.5 3. 5 5 5 3 35 5 h FE TANSISTO CUENT GAIN Figure 5. DC output voltage vs. transistor current gain fig 5a Q 3 9 Q I CQ = ma Q 5 V CC ADDITIONAL BUFFE STAGE V OUT LOW IMPEDANCE LOAD OUTPUT POWE P S, INPUT CUENT I S 9 8 7 6 5 3 P S (mw) I S (ma) 5 5 75 5 5 T S CASE TEMPEATUE C 75 Figure 6. Output buffer stage for low impedance loads Figure 7. Thermal derating curve, dependence of safety limiting value with case fig temperature 7b per IEC/ EN/DIN EN 677-5- 5 fig 6
Conversion from HCPL 56 to In order to obtain similar circuit performance when converting from the to the, it is recommended to increase the Quiescent Input Current, I FQ, from 6 ma to ma. If the application circuit in Figure is used, then potentiometer should be adjusted appropriately. Design Considerations of the Application Circuit The appïication circuit in Figure incorporates several features that help maximize the bandwidth performance of the /. Most important of these features is peaked response of the detector circuit that helps extend the frequency range over which the voltage gain is relatively constant. The number of gain stages, the overall circuit topology, and the choice of DC bias points are all consequences of the desire to maximize bandwidth performance. To use the circuit, first select to set V E for the desired LED quiescent current by: V E G V V E I FQ = () ( I PB / I F ) 7 9 For a constant value V i Fp-p V IN / INp-p, the circuit topology () (adjusting V the E Ggain V V with E ) preserves linearity by keeping I i FQ = Fp-p the i PBp-p modulation V INp-p factor (MF) dependent only () ( I = PB / I F ) 7 on V 9 (3) I E. FQ V I PB Q E E G V V E i I FQ = Fp-p V IN / () () ( I i PB / I F ) F(p-p) V 7 9 INp-p Factor i (MF): = () Fp-p i PBp-p I FQ V E G V V INp-p E FQ V i I E () FQ = Fp-p = (3) I IN / FQ I () ( PB / PB Q () V E ( IG PB V / V I E F E ) I 7 FQ = 9 () ( I PB / I F ) 7 9 i Fp-p i PBp-p V V INp-p 9 Fp-p O = V CC IN /V BE i [V BE X - (I PB Q - I BXQ ) 7 ] (5) F(p-p) = V INp-p (3) () Factor Modulation i Fp-p V I IN FQ (MF): I () PB Q V i E = () Fp-p V IN / Fp-p I FQ V () i PBp-p INp-p E Fp-p i PBp-p V INp-p (3) i i F(p-p) V INp-p Factor FQ = (MF): (3) I Fp-p i FQ I PBp-p V INp-p PB Q V = E = () (3) G V E I V I FQ I 9 O PB = Q V CC I PB V Q BE FQ V E V [V E BE X - (I PB Q - I BXQ ) 7 ] (5) (6) 7 9F(p-p) INp-p Factor (MF): i INp-p Factor For a given (MF): G () V, iv = FQ () F(p-p) E, and V CC, DC output voltage will vary I V 9 O = V CC V BE FQ INp-p V Factor only with (MF): h [V E FEX. = BE X - (I PB Q - I BXQ ) 7 ] (5) () I FQ V CC - V V E BE BXQ G V V E I PB Q (7) (6) CC 67 BE h 9FE X V 9 [V BE (I PB BXQ (5) O = V CC V BE [V BE X - (I PB Q - I BXQ ) 7 ] (5) V 9 O = V CC G V V BE E [V BE X - (I PB Q - I BXQ ) 7 ] (5) I PB Q Where: V O.5 V (6) I CQ 9. ma (8) V 7 CC - 9 V 7 BE BXQ (7) 6 h PB G V V E I FE X (6) PB Q G (6) V V V 7 E I CC - 9 PB Q V I BE (6) BXQ 9 7 9 * V (9) (7) and, O.5 V I CQ + s 9 C 9. ma (8) 6 h FE X CC 7 BE CQ 3 + BXQ V CC - V BE f T I (7) BXQ VV O (7) CC - FE.5 V I CQ 9. ma (8) 6 h V I FE X BE BXQ (7) 9 6 h FE 7 X * V OUT I PB 7 (9) 9 G V + s.5 9 C CQ CQ 3 + 9. ma () (8) V O.5 V I CQ V IN I F f T 7 9. ma (8) 9 V O.5 7 V I CQ 6 * 9. ma (9) (8) + 7 s I where typically 9 C CQ PB 3 + =.3 V OUT I PB I F 7 f T 9 9 G V (9) * () (9) 9 + s C + V O = V CC V BE [V BE X - (I PBQ - I BXQ ) 7 ] (5) I FQ = 9 ( I PB / I F ) 7 9 () 9 V O = V CC V BE [V BE X - (I PBQ - I BXQ ) 7 ] (5) i Fp-p V IN / () G V V E I i PBQ Fp-p (6) i PBp-p V 7 INp-p 9 = (3) I FQ G V I PB V EQ V E I Figure PBQ (6) 5 shows 7 9 the dependency of the DC output voltage on V CC h FEX -. i F(p-p) V I BE V INp-p Factor BXQ (MF): = () (7) For 9 V < V 6 CC < h FE I X V, FQ select the V E value of such that V CC - V I BE BXQ (7) V 6 h FE O.5 X V V I CQ 9. ma (8) 9 O = V CC V BE [V BE X - (I PBQ - I BXQ ) 7 ] (5) 7 V O.5 V The I CQ 9. ma (8) voltage gain 7 of the second stage (Q 3 ) is approximately 9 * equal to: (9) G V V E I PBQ + s 9 C CQ 3 + (6) 9 7 9 f T * (9) + s 9 C CQ 3 + f T VV CC - OUT IV I BE PB 7 9 G BXQ V (7) Increasing () V 6 IN h( FE I X includes F the parallel combination of and Vthe OUT load I PB impedance) 7 9 or reducing G V 9 (keeping () I where 9 / ratio typically V IN Vconstant) O.5 I F PB will V improve the bandwidth. I = CQ 9..3 ma (8) If it is necessary 7 I to F drive a low impedance load, bandwidth I where typically may also PB be =.3 preserved by adding an additional emitter I following F the buffer stage (Q 9 5 in Figure * 6), in which case (9) can be increased to + s set I CQ ma. 9 C CQ 3 + f T Finally, adjust to achieve the desired voltage gain. V OUT I PB 7 9 G V () V IN I F I PB where typically I F Definition: G V = Voltage Gain =.3 I FQ = Quiescent LED forward current i Fp-p = Peak-to-peak small signal LED forward current V INp-p = Peak-to-peak small signal input voltage i PBp-p = Peak-to-peak small signal base photo current I PBQ = Quiescent base photo current V BEX = Base-Emitter voltage of / transistor I BXQ = Quiescent base current of / transistor h FEX = Current Gain (I C /I B ) of / transistor V E = Voltage across emitter degeneration resistor f T = Unity gain frequency of Q 5 C CQ3 = Effective capacitance from collector of Q 3 to ground
For product information and a complete list of distributors, please go to our website: www.avagotech.com Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies Limited in the United States and other countries. Data subject to change. Copyright 5-8 Avago Technologies Limited. All rights reserved. Obsoletes AV-57EN AV-36EN - June 3, 8