LINEAR LT1206 handbook
Contents
1. 1206 RHE AVE D LT1206 TECHNOLOGY 250mA 60MMHz Current Feedback Amplifier FEATURES DESCRIPTION m 250mA Minimum Output Drive Current The LT1206 is a current feedback amplifier with high m 60MHz Bandwidth Ay 2 Ry 1000 output current drive capability and excellent video char 900V us Slew Rate Ay 2 Ry 500 acteristics The LT1206 is stable with large capacitive m 0 02 Differential Gain Ay 2 Ry 300 loads and can easily supply the large currents required 0 17 Differential Phase Ay 2 Ry 300 by the capacitive loading A shutdown feature switches m High Input Impedance 10MQ the device into a high impedance low current mode m Wide Supply Range 5V to 15V reducing dissipation when the device is not in use For m Shutdown Mode 15 lt 200 lower bandwidth applications the supply current can be m Adjustable Supply Current reduced with a single external resistor The low differen m Stable with Cj 10 000pF tial gain and phase wide bandwidth and the 250mA minimum output current drive make the LT1206 well APPLICATIONS Suited to drive multiple cables in video systems Video Amplifiers The LTI 206 is manufactured on Linear Technology s Cable Drivers proprietary complementary bipolar process RGB Amplifiers m Test Equipment Amplifiers m Buffers TYPICAL APPLICATIONS Noninverting Amplifier with Shutdown Large Signal Response C 10 000pF 15V OPTIONAL USE WI2. 100 90 PEAKING lt 0 5dB Ay 2 PEAKING 5dB R 1000 _ 80 Rr 4700_ 5600 5 60 2 Rr 6800 50 5 40 Rr 7500 5 30 20 Rr 1k 10 1 5k 0 4 6 8 10 12 14 16 18 SUPPLY VOLTAGE V LT1206 TPCO1 Bandwidth vs Supply Voltage 100 go L PEAKING lt PEAKING lt _ 80 70 60 50 40 3 30 20 10 Re 1 5k 0 4 6 8 10 12 14 16 18 SUPPLY VOLTAGE V LT1206 04 Differential Phase vs Supply Voltage 0 50 150 g 040 a 2 0 30 Rr Rg 5602 z E 0 20 302 2 0 10 R 1500 0 5 7 9 11 13 15 SUPPLY VOLTAGE V 171206 07 Bandwidth vs Supply Voltage 50 PEAKING lt 0 5dB Ay 2 PEAKING 5dB R 2100 40 f Re 5602 2 2 30 47 L RF 7509 a 5 T Rr 1k 3 Rr 2k 10 0 4 6 8 10 12 14 16 18 SUPPLY VOLTAGE V LT1206 02 Bandwidth vs Supply Voltage 50 PEAKING lt 0 5dB Ay 10 PEAKING 5dB R_ 100 _ 40 30 Rr 5600 a ua nm al anaes J gt 20 Rr 6800 E Rr 1k 10 1 5 4 6 8 10 12 14 16 18 SUPPLY VOLTAGE V LT1206 TPC05 Dif
3. FREQUENCY Hz 1111206 09 5 11206 TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage Supply Current vs Ambient Temperature Vs 5V 24 Vs p OV Ty 40 C Z 20 z Ty 25 C c a 46 8 gt 850 gt a Ty 125 C 12 10 0 4 6 8 10 12 14 16 18 50 25 0 25 50 75 100 125 SUPPLY VOLTAGE V TEMPERATURE C LT1206 TPC10 LT1206 TPC11 Supply Current Input Common Mode Limit vs Shutdown Pin Current vs Junction Temperature 20 vt MESE N 2216 S 1 0 lt lt 0 25 20 amp 10 CAE 2 9 8 gt 20 6 Sg 15 P 4 8 10 2 0 5 j 0 100 200 300 400 500 50 25 0 25 50 75 100 125 SHUTDOWN PIN CURRENT uA TEMPERATURE C LT1206 TPC11 LT1206 TPC14 Output Saturation Voltage Power Supply Rejection Ratio vs Junction Temperature vs Frequency Vs 15V RL 2k 1 C ee i 9 gt 9 2 CTF 50a z o 3 Es BI 1 gt 500 E cc gt 2 5 RL 2k S O p eee et 50 25 0 25 50 75 1
4. FREQUENCY MHz LT1206 F01 Figure 1 which is flat to 0 35dB to 30MHz The network has the greatest effect for Cj in the range of OpF to 1000pF The graph of Maximum Capacitive Load vs Feedback Resistor can be used to select the appropriate value of feedback resistor The values shown are for 0 5dB and 5dB peaking at a gain of 2 with no resistive load This is a worst case condition as the amplifier is more stable at higher gains and with some resistive load in parallel with the capaci tance Also shown is the 3dB bandwidth with the sug gested feedback resistor vs the load capacitance Although the optional compensation works well with capacitive loads it simply reduces the bandwidth when it is connected with resistive loads For instance with a 300 load the bandwidth drops from 55MHz to 35MHz when the compensation is connected Hence the compensation was made optional To disconnectthe optional compensa tion leave the COMP pin open Shutdown Current Set If the shutdown feature is not used the SHUTDOWN pin must be connected to ground or V The shutdown can be used to either turn off the biasing for the amplifier reducing the quiescent current to less than 200yA or to control the quiescent current in normal operation The total bias current in the LT1206 is controlled by the current flowing out of the shutdown pin When the shut down pin is open or driven to the positive supply the part is shut down In
5. 0 244 0 150 0 157 5 791 6 197 3 810 3 988 Y 1 2 3 4 0 010 0 020 0 254 0 508 0 053 0 069 45 1 346 1 752 0 004 0 010 0 008 0 010 0 004 0 010 0 203 0 254 0254 ph i dad s 0 016 0 050 1 A 0 014 0 019 0 050 0355 0483 1 270 BSC 08 0392 Y Package 7 Lead 0 220 0390 0410 ideas 9 91 10 41 373 224 199 0185 DIA 129 470 0 045 0 055 1 14 1 40 NU 0 235 0 258 5 97 6 55 0 103 0 113 2 62 2 87 0 700 0 728 17 78 18 49 Y 0 152 0 202 Y 3 86 5 13 Y Y 0 260 0 320 T 6 60 8 13 0026 0036 0 66 0 91 0 006 0 002 0095 0115 006 208 sll 0 41 0 56 2 41 2 92 4t 0 135 0 165 0 155 0 195 8343 449 3 94 4 95 Information furnished by Linear Technology Corporation is believed to be accurate and reliable y CAR However no responsibility is assumed for its use Linear Technology Corporation makes no represen TECHNOLOGY tation that the interconnection of circuits as described herein will not infringe on existing patent rights 11206 NORTHEAST REGION Linear Technology Corporation One Oxford Valley 2300 E Lincoln Hwy Suite 306 Langhorne PA 19047 Phone 215 757 8578 FAX 215 757 5631 Linear Tec
6. 70 C ambient temperature 15V 111206 F07 Figure 7 Thermal Calculation Example The device dissipation can be found by measuring the supply currents calculating the total dissipation and then subtracting the dissipation in the load and feedback network Pp 9 x 30V 12V 2k 2k 1 03W Then Tj 1 03W 100 C W 70 C 173 C for the N8 package Ty 1 03W x 65 C W x 70 C 137 C for the 58 with 225 sq mm topside heat sinking Ty 1 08W x 35 C W x 70 C 106 C for the R package with 100 sq mm topside heat sinking Since the Maximum Junction Temperature is 150 C the N8 package is clearly unacceptable Both the S8 and R packages are usable 12 WIEN 11206 TYPICAL APPLICATIONS Precision x10 Hi Current Amplifier Vin LT1206 COMP OUT 111206 TA03 OUTPUT OFFSET 500uV SLEW RATE 2V us BANDWIDTH 4MHz STABLE WITH C 10nF Low Noise x10 Buffered Line Driver 15 uF 15V 1 LT1206 TA04 1000 320 Vo 5VnMs THD NOISE 0 0009 1kHz 0 004 AT 20kHz SMALL SIGNAL 0 1dB BANDWIDTH 600kHz CMOS Logic to Shutdown Interface 15V LT1206 TAOS 71206 TA06 Buffer Ay 1 Vout OPTIONAL USE WITH CAPACITIVE LOADS VALUE OF Rr DEPENDS ON SUPPLY VOLTAGE AND LOADING SELECT FROM TYPICAL AC PERFORMANCE TABLE OR DETERMINE EMPIRICALLY 0 01uF LT1206 TA07 13 1
7. MIN TYP MAX UNITS Vos Input Offset Voltage 25 C 3 10 mV e 15 mV Input Offset Voltage Drift 10 uV C lin Noninverting Input Current 25 C 2 8 25 lin Inverting Input Current Ta 25 C 10 60 100 en nput Noise Voltage Density f 10kHz Rf 1k Rg 100 Rs 00 3 6 nV AHz tip nput Noise Current Density f 10kHz Rf 1k Rg 100 Rs 10k 2 pA NHz Noise Current Density f 10kHz Re 1k Rg 100 Rs 10k 30 pA VHz Rin nput Resistance Vin 12V Vs 15V 1 5 10 MQ Vin 2V Vg 5V 0 5 5 MQ Cin nput Capacitance Vg 15V 2 pF nput Voltage Range Vs 151 12 13 5 Vs 5V 2 3 5 WIEN 11206 ELECTRICAL CHARACTERISTICS vov o 5v lt v lt 15v pulse tested Vgm OV unless otherwise noted SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS CMRR Common Mode Rejection Ratio Vs 151 Vem 121 55 62 dB Vs 51 Vom 21 50 60 dB Inverting Input Current Vs 151 Vem 121 0 1 10 pA V Common Mode Rejection Vs 5V Vom 2V 0 1 10 pA V PSRR Power Supply Rejection Ratio Vs 5V to 15V e 60 77 dB Noninverting Input Current Vg 5V to 15 30 500 nA V Power Supply Rejection Inverting Input Current Vs 5V to 15V 0 7 5 pA V Power Supply Rejection Ay Large Signal Voltage Gain Vg 15V Vout 10
8. to 10mA with Vs 15V The photos Figures 4a and 4b show the effect of reducing the quiescent supply current on the large signal response The quiescent current can be reduced to 5mA in the inverting configuration without much change in response In noninverting mode however the slew rate is reduced as the quiescent current is reduced 4 71206 F04a Rr 7500 500 la 5 10mA 20 Vs 151 Figure 4 Large Signal Response vs Ig Ay 1 111206 F04b lg 5mA 10mA 20mA Vs 151 Figure 4b Large Signal Response vs Ig Ay 2 Rr 7500 500 Slew Rate Unlike a traditional op amp the slew rate of a current feedback amplifier is not independent of the amplifier gain configuration There are slew rate limitations in both the input stage and the output stage In the inverting mode and for higher gains in the noninverting mode the signal amplitude on the input pins is small and the overall slew rate is that of the output stage The input stage slew rate is related to the quiescent current and will be reduced as the supply current is reduced The output slew rate is set by the value of the feedback resistors and the internal capacitance Larger feedback resistors will reduce the slew rate as will lower supply voltages similar to the way the bandwidth is reduced The photos Figures 5a 5b and 5 show the large signal response of the LT1206 for various gain configurations The slew rate
9. varies from 860V us for a gain of 1 to 1400V us for a gain 04 1 LT1206 F05a Vg 15V Rr 8250 Ry 500 Figure 5a Large Signal Response Ay 1 111206 050 Re RG 750Q V 15V Ry 500 Figure 5b Large Signal Response Ay 1 10 WIEN 11206 APPLICATIONS INFORMATION 21 1100 71206 F04c Rf 7500 500 Figure 5c Large Signal Response Ay 2 When the LT1206 is used to drive capacitive loads the available output current can limit the overall slew rate In the fastest configuration the LT1206 is capable of a slew rate of over 1V ns The current required to slew a capacitor at this rate is 1mA per picofarad of capacitance so 10 000pF would require 10A The photo Figure 6 shows the large signal behavior with 10 000pF The slew rate is about 60V us determined by the current limit of 600mA 171206 F06 Vg 15 RL Re RG 3k Figure 6 Large Signal Response C 10 000pF Differential Input Signal Swing The differential input swing is limited to about 6V by an ESD protection device connected between the inputs In normal operation the differential voltage between the input pins is small so this clamp has no effect however in the shutdown mode the differential swing can be the same as the input swing The clamp voltage will then set the maximum allowable input voltage To allow for some margin it is recommended that the i
10. 00 125 10k 100k 1 10M 100M TEMPERATURE C FREQUENCY Hz LT1206 TPC16 LT1206 TPC17 SUPPLY CURRENT mA OUTPUT SHORT CIRCUIT CURRENT A SUPPLY CURRENT mA Supply Current vs Ambient Temperature Vs 15V 25 1 Rsp 00 Ri 20 15 Rgp 60 4k 10 Rsp 121k 5 0 50 25 0 25 50 75 100 125 TEMPERATURE C LT1206 TPC12 Output Short Circuit Current vs Junction Temperature 1 0 0 9 0 8 0 7 0 6 0 5 0 4 0 3 50 25 0 25 50 75 100 125 TEMPERATURE C LT1206 TPC15 Supply Current vs Large Signal Output Frequency No Load 60 Ay 2 RL 50 9 15V Vout 20Vp p 40 30 20 10 10k 100k 1M 10M FREQUENCY Hz LT1206 TPC18 WIEN 11206 TYPICAL PERFORMANCE CHARACTERISTICS Output Impedance in Shutdown 2nd and 3rd Harmonic Distortion Output Imp
11. 11206 PACKAGE DESCRIPTION Dimensions in inches millimeters unless otherwise noted 8 Package 8 Lead Plastic DIP 0 250 0 010 6 350 0 254 0 300 0 320 0 045 0 065 0 130 0 005 gt lt iS BAN AAS 7 620 8 128 1 143 1 651 3 302 0 127 oos 4 1 651 0 009 0 015 TYP age a 0 229 0 381 0 125 3 175 0 020 0325 0028 0 045 0 015 MIN 0 508 o 1 143 0 381 MIN 42052 010020010 1 0 018 0 003 2 540 0 254 0 457 0 076 R Package 7 Lead Plastic DD 0 060 0401 0 015 10 185 0 381 4 445 0 203 P 0 050 0 008 15 TYP 1 270 0 203 0 331 0 059 004 0008 1 499 0 203 7 0208 0102 9102 Y y L 0 105 0 008 2 667 0 203 A 0 050 0 010 0 143 0 012 m H 127020286 0 022 0 005 4l UO 0 030 0 008 0 559 0 127 7 0 305 gt lt 3 632 0 762 0 203 0 508 5 DD7 0693 14 YR 11206 PACKAGE DESCRIPTION Dimensions in inches millimeters unless otherwise noted 8 Package 8 Lead Plastic SOIC 0 189 0 197 4 801 5 004 8 7 6 5 0 228
12. 500 55 71 dB Vs 51 2V Ry 250 55 68 dB Rot Transresistance AVoyr AliN Vg 15 Vgyr 10V 500 100 260 Vg 5V Vout 2V Ry 250 75 200 kQ Vout Maximum Output Voltage Swing Vs 15V Ry 500 25 C 11 5 12 5 V e 10 0 V Vg 5V Ri 250 TA 25 C 2 5 3 0 e 20 lout Maximum Output Current Ry 1 250 500 1200 mA Is Supply Current Vg 15V OV Ta 25 C 20 30 mA 35 mA Supply Current Rsyp 51k Note 3 Vg 15V Ta 25 C 12 17 mA Positive Supply Current Shutdown Vs 15V 15V 200 Output Leakage Current Shutdown Vs 15 15V 10 SR Slew Rate Note 4 Ay 2 Ta 25 400 900 V us Differential Gain Note 5 Vg 15V 5600 Rg 5600 300 0 02 Differential Phase Note 5 Vg 15V Rr 5600 Rg 5600 300 0 17 DEG BW Small Signal Bandwidth Vg 15V Peaking lt 0 5dB 60 MHz Rr Rg 6200 1000 Vg 15V Peaking lt 0 5dB 52 MHz Rr Rg 6490 50Q Vg 15V Peaking lt 0 5dB 43 MHz Rr Rg 6980 R 300 Vg 15V Peaking lt 0 5dB 27 MHz Rf Rg 825Q R 100 The e denotes specifications which apply for 0 C lt Ty lt 70 C beyond 0 C to 70 C Industrial grade parts tested over 40 to 85 C are Note 1 Applies to short circuits to ground only A short circuit between the output and either supply may permanently damage the pa
13. ELEX 499 3977 SOUTHWEST REGION Linear Technology Corpora tion 22141 Ventura Blvd Suite 206 Woodland Hills CA 91364 Phone 818 703 0835 FAX 818 703 0517 NORTHWEST REGION Linear Technology Corpora tion 782 Sycamore Dr Milpitas CA 95035 Phone 408 428 2050 FAX 408 432 6331 TAIWAN Linear Technology Corporation Rm 801 No 46 Sec 2 Chung Shan N Rd Taipei Taiwan R O C Phone 886 2 521 7575 FAX 886 2 562 2285 UNITED KINGDOM Linear Technology UK Ltd The Coliseum Riverside Way Camberley Surrey GU15 3YL United Kingdom Phone 44 276 677676 FAX 44 276 64851 06 24 93 sn1206 1206fs LT GP 0993 10K REV 0 PRINTED IN USA LY LIEN LINEAR TECHNOLOGY CORPORATION 1993
14. MHz MHz Vs 51 Rgp 10 2k Vs 151 Rgp 60 4k ej 150 576 576 35 17 1 150 634 634 41 19 1 30 681 681 25 12 5 30 768 768 26 5 14 10 750 750 16 4 8 7 10 866 866 17 94 1 150 665 37 17 5 1 150 768 44 18 8 30 768 25 12 6 30 909 28 14 4 10 845 16 5 8 2 10 1k 16 8 8 3 2 150 590 590 35 16 8 2 150 649 649 40 18 5 30 681 681 25 13 4 30 787 787 27 141 10 768 768 16 2 8 1 10 931 931 16 5 8 1 10 150 301 33 2 31 15 6 10 150 301 33 2 33 15 6 30 392 43 2 23 11 9 30 402 44 2 25 13 3 10 499 54 9 15 7 8 10 590 64 9 15 3 7 4 15 5mA Typical Peaking lt 0 1dB 3dB BW 0 1dB BW 3dB BW 0 1dB BW Ay RL Rf Rg MHz MHz Ay Rg MHz MHz Vs 51 Rgp 22 1k Vs 151 121k 1 150 604 604 21 10 5 1 150 619 619 25 12 5 30 715 715 14 6 7 4 30 787 787 15 8 8 5 10 681 681 10 5 6 0 10 825 825 10 5 5 4 1 150 768 20 9 6 1 150 845 23 10 6 30 866 141 6 7 30 1k 15 3 7 6 10 825 9 8 5 1 10 1k 10 5 2 2 150 634 634 20 9 6 2 150 681 681 23 10 2 30 750 750 14 1 7 2 30 845 845 15 7 7 10 732 732 9 6 5 1 10 866 866 10 5 4 10 150 100 11 1 16 2 5 8 10 150 100 11 1 15 9 4 5 30 100 11 1 13 4 7 0 30 100 11 1 13 6 6 10 100 11 1 9 5 4 7 10 100 11 1 9 6 4 5 WIEN 11206 TYPICAL PERFORMANCE CHARACTERISTICS Bandwidth vs Supply Voltage
15. TH CAPACITIVE LOADS GROUND SHUTDOWN PIN FOR NORMAL OPERATION Vs 15V LT1206 TAO2 11206 ABSOLUTE MAXIMUM RATINGS Supply Voltage 18V Operating Temperature Range GUMGUE ciens a 15mA Seen an ee 40 to 85 C Output Short Circuit Duration Note 1 Continuous Junction 150 C Specified Temperature Range Note 2 0 C to 70 C Storage Temperature Range 65 C to 150 C Lead Temperature Soldering 10 sec 300 C PACKAGE ORDER INFORMATION TOP VIEW ORDER PART TOP VIEW ORDER PART ne 1 8 Vt NUMBER vi 8 v NUMBER IN 2 7 OUT IN 2 7 OUT 52 3 6 V7 LT1206CN8 3 6 111206058 S D 4 5 COMP S D 4 5 COMP PART MARKING N8 PACKAGE 58 PACKAGE 8 LEAD PLASTIC DIP 8 LEAD PLASTIC SO 1 206 64 100 C W 60 C W FRONT VIEW ORDER PART FRONT VIEW ORDER PART NUMBER NUMBER LT1206CR LT1206CY UN IN Y PACKAGE 7 LEAD PLASTIC DD 7 LEAD 0 220 8a 30 C W 5 C W Ground shutdown pin for normal operation See Note 2 ELECTRICAL CHARACTERISTICS Vem 0 5V lt Vs lt 15V pulse tested Vs p OV unless otherwise noted SYMBOL PARAMETER CONDITIONS
16. bient tem perature until the device begins thermal shutdown gives a good indication of how much margin there is in the thermal design For surface mount devices heat sinking is accomplished by using the heat spreading capabilities of the PC board and its copper traces Experiments have shown that the heat spreading copper layer does not need to be electri cally connected to the tab of the device The PCB material can be very effective at transmitting heat between the pad area attached to the tab of the device and a ground or 11 11206 APPLICATIONS INFORMATION power plane layer either inside or on the opposite side of the board Although the actual thermal resistance of the PCB material is high the length area ratio of the thermal resistance between the layer is small Copper board stiff eners and plated through holes can also be used to spread the heat generated by the device Tables 1 and 2 listthermal resistance for each package For the TO 220 package thermal resistance is given for junc tion to case only since this package is usually mounted to a heat sink Measured values of thermal resistance for several different board sizes and copper areas are listed for each surface mount package All measurements were taken in still air on 3 32 FR 4 board with 107 copper This data can be used as a rough guideline in estimating thermal resistance The thermal resistance for each appli cation will be affected by th
17. edance vs Frequency vs Frequency vs Frequency 100 100k 30 Vs 15V Ay 1 lo OMA Re 1k Vs 15 7 ZR Rsyp 121k 5 amp 10 amp 8 50 a 4 Rep 00 2 60 E E amp 01 o 100 80 0 01 10 90 100k 1 10M 100M 100k 1 10M 100M 1 2 3 4 56728910 FREQUENCY MHz FREQUENCY Hz FREQUENCY Hz LT1206 TPC19 LT1206 TPC20 TPCA 3rd Order Intercept vs Frequency Test Circuit for 3rd Order Intercept 60 T Vs 15V 2500 X Rf 5900 5 5 Rg 64 90 Po E 40 i 30 650 500 5 MEASURE INTERCEPT AT Po 5 20 L11206 TPc23 0 5 10 15 20 25 30 FREQUENCY MHz LT1206 TPC22 11206 SIMPLIFIED SCHEMATIC TO ALL CURRENT SOURCES 018 017 SHUTDOWN LT1206 TC APPLICATIONS INFORMATION The 171206 is a current feedback amplifier with high output current drive capability The device is stable with large capacitive loads and can easily supply the high currents required by capacitive loads The amplifier will drive low impedance loads such as cables with excellent linearity at high frequencies Feedback Resistor Selection The optimum value for the feedback resistors is a function of the operating conditions of the device the load imped ance and the desired flatness of response The Typical AC Performance tables give the values which result in the highest 0 1dB and 0 5dB bandwidths for various resis
18. ermal interactions with other components as well as board size and shape Table 1 R Package 7 Lead DD COPPER AREA THERMAL RESISTANCE TOPSIDE BACKSIDE BOARD AREA JUNCTION TO AMBIENT 2500 sq mm 2500 sq mm 2500 sq mm 25 C W 1000 sq mm 2500 sq mm 2500 sq mm 27 C W 125sq mm 2500 9 2500 sq mm 35 C W Tab of device attached to topside copper Table 2 8 Package 8 Lead Plastic SOIC COPPER AREA THERMAL RESISTANCE TOPSIDE BACKSIDE BOARD AREA JUNCTION TO AMBIENT 2500 sq mm 2500 sq mm 2500 sq mm 60 C W 1000 sq mm 2500 sq mm 2500 sq mm 62 C W 225 sq mm 2500 sq mm 2500 sq mm 65 C W 100 sq mm 2500 sq mm 2500 sq mm 69 C W 100 sq mm 1000 sq mm 2500 sq mm 73 C W 100 sq mm 225 sq mm_ 2500 sq mm 80 C W 100 sq mm 100 50 mm 2500 sq mm 83 C W Pins 1 and 8 attached to topside copper Y Package 7 Lead T0 220 Thermal Resistance Junction to Case 5 C W N8 Package 8 Lead DIP Thermal Resistance Junction to Ambient 100 C W Calculating Junction Temperature The junction temperature can be calculated from the equation Ty Pp x where Ty Junction Temperature Ta Ambient Temperature Pp Device Dissipation Thermal Resistance Junction to Ambient As an example calculate the junction temperature for the circuit in Figure 7 forthe S8 and R packages assuming a
19. ferential Gain vs Supply Voltage 0 10 T T T Rr Rg 5602 Ay 2 1 0 08 150 N PACKAGE 3 lt 0 06 R 300 a ac 0 04 500 gt lt a 0 02 Ry 1500 0 5 7 9 11 13 15 SUPPLY VOLTAGE V LT1206 08 Bandwidth and Feedback Resistance vs Capacitive Load for 0 5dB Peak 10k 100 BANDWIDTH eo brand e x B 4k 10 g 1 11 I ss FEEDBACK RESISTOR T LAy 2 n LRL Vs 15V Ccomp 0 01 uF 100 1 1 10 100 1000 10000 CAPACITIVE LOAD pF LT1206 Bandwidth and Feedback Resistance vs Capacitive Load for 5dB Peak 10k 100 BANDWIDTH a z t5 wn dk 10 TS 5 42 FEEDBACK RESISTOR Vg 15V 0 01 uF 100 Le gano ro rain 1 10 100 1k 10k CAPACITIVE LOAD pF LT1206 TPCO6 Spot Noise Voltage and Current vs Frequency 100 E us E e 10 N amp i 5 1 10 100 1k 10k 100k
20. hnology Corporation 266 Lowell St Suite B 8 Wilmington MA 01887 Phone 508 658 3881 FAX 508 658 2701 FRANCE Linear Technology S A R L Immeuble Le Quartz 58 Chemin de la Justice 92290 Chatenay Malabry France Phone 33 1 41079555 FAX 33 1 46314613 GERMANY Linear Techonolgy GMBH Untere Hauptstr 9 D 85386 Eching Germany Phone 49 89 3197410 FAX 49 89 3194821 JAPAN Linear Technology KK 5F YZ Bldg 4 4 12 lidabashi Chiyoda Ku Tokyo 102 Japan Phone 81 3 3237 7891 FAX 81 3 3237 8010 U S Area Sales Offices SOUTHEAST REGION Linear Technology Corporation 17060 Dallas Parkway Suite 208 Dallas TX 75248 Phone 214 733 3071 FAX 214 380 5138 CENTRAL REGION Linear Technology Corporation Chesapeake Square 229 Mitchell Court Suite A 25 Addison IL 60101 Phone 708 620 6910 FAX 708 620 6977 International Sales Offices KOREA Linear Technology Korea Branch Namsong Building 505 Itaewon Dong 260 199 Yongsan Ku Seoul Korea Phone 82 2 792 1617 FAX 82 2 792 1619 SINGAPORE Linear Technology Pte Ltd 101 Boon Keng Road 02 15 Kallang Ind Estates Singapore 1233 Phone 65 293 5322 FAX 65 292 0398 World Headquarters Linear Technology Corporation 1630 McCarthy Blvd Milpitas CA 95035 7487 Phone 408 432 1900 FAX 408 434 0507 1 Linear Technology Corporation 1630 McCarthy Blvd Milpitas CA 95035 7487 408 432 1900 FAX 408 434 0507 T
21. nput signal be less than 5V when the device is shut down Capacitance on the Inverting Input Current feedback amplifiers require resistive feedback from the outputto the inverting input for stable operation Take care to minimize the stray capacitance between the output and the inverting input Capacitance on the invert ing input to ground will cause peaking in the frequency response and overshoot in the transient response but it does not degrade the stability of the amplifier Power Supplies The LT1206 will operate from single or split supplies from 5V 10V total to 15V 30V total It is not necessary to use equal value split supplies however the offset voltage and inverting input bias current will change The offset voltage changes about 500uV per volt of supply mis match The inverting bias current can change as much as 5uA per volt of supply mismatch though typically the change is less than 0 5uA per volt Thermal Considerations The LT1206 contains a thermal shutdown feature which protects against excessive internal junction tempera ture If the junction temperature of the device exceeds the protection threshold the device will begin cycling be tween normal operation and an off state The cycling is not harmful to the part The thermal cycling occurs at a slow rate typically 10ms to several seconds which depends on the power dissipation and the thermal time constants of the package and heat sinking Raising the am
22. rt when operated on supplies greater than 10V Note 2 Commercial grade parts are designed to operate over the temperature range of 40 C to 85 C but are neither tested nor guaranteed available on special request Consult factory Note 3 is connected between the shutdown pin and ground Note 4 Slew rate is measured at 5V on a 10V output signal while operating on 15V supplies with Rp 1 5k Rg 1 5k and R 4000 Note 5 NTSC composite video with an output level of 2V 11206 SMALL SIGNAL BANDWIDTH 15 20mA Typical Peaking lt 0 1dB 3dB BW 0 1dB BW 3dB BW 0 1dB BW Ay RL Rf Rc MHz MHz Ay Ri Rr Rc MHz MHz Vs 51 00 Vs 151 00 1 150 562 562 48 21 4 1 150 681 681 50 19 2 30 649 649 34 17 30 768 768 35 17 10 732 732 22 12 5 10 887 887 24 12 3 1 150 619 54 22 3 1 150 768 66 22 4 30 715 36 17 5 30 909 37 17 5 10 806 22 4 11 5 10 1k 23 12 2 150 576 576 48 20 7 2 150 665 665 55 23 30 649 649 35 181 30 787 787 36 18 5 10 750 750 22 4 VAL 10 931 931 22 5 11 8 10 150 442 48 7 40 19 2 10 150 487 536 44 20 7 30 511 56 2 31 16 5 30 590 64 9 33 17 5 10 649 71 5 20 10 2 10 768 84 5 20 7 10 8 1 10mA Typical Peaking lt 0 1dB 3dB BW 0 14 BW 34 BW 0 1dB BW Ay RL Rf Rc MHz MHz Ay RL Rf
23. the shutdown mode the output looks like a40pF capacitor and the supply current is typically 100p4A The shutdown pin is referenced to the positive supply through an internal bias circuit see the simplified sche matic An easy way to force shutdown is to use open drain collector logic The circuit shown in Figure 2 uses a 746904 buffer to interface between 5V logic and the LT1206 The switching time between the active and shut down states is less than 1us A 24k pull up resistor speeds up the turn off time and insures that the LT1206 is completely turned off Because the pin is referenced to the positive supply the logic used should have a break down voltage of greater than the positive supply voltage No other circuitry is necessary as the internal circuit limits the shutdown pin current to about 500pA Figure shows the resulting waveforms Figure 2 Shutdown Interface Vour ENABLE LT1206 F3 Ay 1 Rpy 24k Re 825Q Viy 1Vp p Ry 500 Figure 3 Shutdown Operation AL 11206 APPLICATIONS INFORMATION For applications where the full bandwidth of the amplifier is not required the quiescent current of the device may be reduced by connecting a resistor from the shutdown pin to ground The quiescent current will be approximately 40 times the current in the shutdown pin The voltage across the resistor in this condition is V 3Vpe For example a 60k resistor will set the quiescent supply current
24. tive loads and operating conditions If this level of flatness is not required a higher bandwidth can be obtained by use of a lower feedback resistor The characteristic curves of Bandwidth vs Supply Voltage indicate feedback resistors for peaking up to 5dB These curves use a solid line when the response has less than 0 5dB of peaking and a dashed line when the response has 0 5dB to 5dB of peaking The curves stop where the response has more than 5dB of peaking For resistive loads the COMP pin should be left open see section on capacitive loads Capacitive Loads The LT1206 includes an optional compensation network for driving capacitive loads This network eliminates most of the output stage peaking associated with capacitive loads allowing the frequency response to be flattened Figure 1 shows the effect of the network on a 200pF load Without the optional compensation there is a 5dB peak at 40MHz caused by the effect of the capacitance on the output stage Adding a 0 01 bypass capacitor between the output and the COMP pins connects the compensation and completely eliminates the peaking A lower value feedback resistor can now be used resulting ina response 8 AL WIEN 11206 APPLICATIONS INFORMATION Vg 15 Rf 1 2k COMPENSATION Rr 2k NO COMPENSATION Rr 2k COMPENSATION VOLTAGE GAIN dB 1 10 100
Download Pdf Manuals
Related Search
LINEAR LT1206 handbook