LT1206 TA mA/60MHz Current Feedback Amplifi er DESCRIPTION FEATURES APPLICATIONS TYPICAL APPLICATION

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1 LT26 2mA/6MHz Current Feedback Amplifi er FEATURES 2mA Minimum Output Drive Current 6MHz Bandwidth, A V = 2, R L = Ω 9V/µs Slew Rate, A V = 2, R L = Ω.2% Differential Gain, A V = 2, R L = Ω.7 Differential Phase, A V = 2, R L = Ω High Input Impedance, MΩ Wide Supply Range, ±V to ±V Shutdown Mode: I S < 2µA Adjustable Supply Current Stable with C L =,p Available in 8-Pin DIP and SO and 7-Pin DD and TO-22 Packages APPLICATIONS Video Amplifiers Cable Drivers RGB Amplifiers Test Equipment Amplifiers Buffers DESCRIPTION The LT 26 is a current feedback amplifier with high output current drive capability and excellent video characteristics. The LT26 is stable with large capacitive loads, and can easily supply the large currents required by the capacitive loading. A shutdown feature switches the device into a high impedance, low current mode, reducing dissipation when the device is not in use. For lower bandwidth applications, the supply current can be reduced with a single external resistor. The low differential gain and phase, wide bandwidth, and the 2mA minimum output current drive make the LT26 well suited to drive multiple cables in video systems. The LT26 is manufactured on Linear Technology s proprietary complementary bipolar process., LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Noninverting Amplifi er with Shutdown Large-Signal Response, CL =,pf V IN V LT26 COMP S/D** C COMP.µF* V V OUT R F ENABLE V V 2k 7C96 R G * OPTIONAL, USE WITH CAPACITIVE LOADS ** GROUND SHUTDOWN PIN FOR NORMAL OPERATION LT26 TA R L = R G = 3k R L = ns/div 26 TA2

2 LT26 ABSOLUTE MAXIMUM RATINGS Supply Voltage...±8V Input Current...±mA Output Short-Circuit Duration (Note 2)...Continuous Specified Temperature Range (Note 3)... C to 7 C PACKAGE/OERDER INFORMATION (Note ) Operating Temperature Range... C to 8 C Junction Temperature... C Storage Temperature Range... 6 C to C Lead Temperature (Soldering, sec)... C TOP VIEW TOP VIEW NC 8 V V 8 V IN IN OUT V IN IN OUT V S/D* COMP S/D* COMP N8 PACKAGE 8-LEAD PLASTIC DIP θ JA = C/W S8 PACKAGE 8-LEAD PLASTIC SO θ JA = 6 C/W ORDER PART NUMBER ORDER PART NUMBER S8 PART MARKING LT26CN8** LT26CS8** 26 FRONT VIEW FRONT VIEW TAB IS V OUT V COMP V S/D* IN IN TAB IS V OUT V COMP V S/D* IN IN R PACKAGE 7-LEAD PLASTIC DD θ JA = C/W ORDER PART NUMBER LT26CR** Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: T7 PACKAGE 7-LEAD PLASTIC TO-22 θ JA = C/W ORDER PART NUMBER LT26CT7** Consult LTC Marketing for parts specified with wider operating temperature ranges. *Ground shutdown pin for normal operation. ** See Note 3. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T A = 2 C. V CM =, ±V V S V, pulse tested, V S/D = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage ±3 ± mv ± mv Input Offset Voltage Drift µv/ C I IN Noninverting Input Current ±2 ±8 µa ±2 µa I IN Inverting Input Current ± ±6 µa ± µa 2

3 Note : Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Applies to short circuits to ground only. A short circuit between the output and either supply may permanently damage the part when operated on supplies greater than ±V. LT26 ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T A = 2 C. V CM =, ±V V S V, pulse tested, V S/D = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS e n Input Noise Voltage Density f = khz, R F = k, R G = Ω, R S = Ω 3.6 nv/ Hz i n Input Noise Current Density f = khz, R F = k, R G = Ω, R S = k 2 pa/ Hz i n Input Noise Current Density f = khz, R F = k, R G = Ω, R S = k pa/ Hz R IN Input Resistance V IN = ±2V, V IN = ±2V, V S = ±V.. MΩ MΩ C IN Input Capacitance 2 pf Input Voltage Range V S = ±V ±2 ±2 ±3. ±3. V V CMRR Common Mode Rejection Ratio, V CM = ±2V V S = ±V, V CM = ±2V 62 6 db db Inverting Input Current Common Mode Rejection, V CM = ±2V V S = ±V, V CM = ±2V.. µa/v µa/v PSRR Power Supply Rejection Ratio V S = ±V to ±V 6 77 db Noninverting Input Current Power Supply V S = ±V to ±V na/v Rejection Inverting Input Current Power Supply V S = ±V to ±V.7 µa/v Rejection A V Large-Signal Voltage Gain, V OUT = ±V, R L = Ω V S = ±V, V OUT = ±2V, R L = 2Ω 7 68 db db R OL Transresistance, ΔV OUT /ΔI IN, V OUT = ±V, R L = Ω V S = ±V, V OUT = ±2V, R L = 2Ω kω kω V OUT Maximum Output Voltage Swing, R L = Ω ±. ±2. V ±. V, R L = 2Ω ±2. ±3. V ±2. V I OUT Maximum Output Current R L = Ω 2 2 ma I S Supply Current, V S/D = V 2 ma 3 ma Supply Current, R S/D = k (Note ) 2 7 ma Positive Supply Current, Shutdown, V S/D = V 2 µa Output Leakage Current, Shutdown, V S/D = V µa SR Slew Rate (Note ) A V = 2 9 V/µs Differential Gain (Note 6), R F = 6Ω, R G = 6Ω, R L = Ω.2 % Differential Phase (Note 6), R F = 6Ω, R G = 6Ω, RL = Ω.7 Deg BW Small-Signal Bandwidth, Peaking.dB, 6 MHz R F = R G = 62Ω, R L = Ω, Peaking.dB, 2 MHz R F = R G = 69Ω, R L = Ω, Peaking.dB, 3 MHz R F = R G = 698Ω, R L = Ω, Peaking.dB, R F = R G = 82Ω, R L = Ω 27 MHz Note 3: Commercial grade parts are designed to operate over the temperature range of C to 8 C but are neither tested nor guaranteed beyond C to 7 C. Industrial grade parts tested over C to 8 C are available on special request. Consult factory. Note : R S/D is connected between the shutdown pin and ground. Note : Slew rate is measured at ±V on a ±V output signal while operating on ±V supplies with R F =.k, R G =.k and R L = Ω. Note 6: NTSC composite video with an output level of 2V. 3

4 LT26 SMALL-SIGNAL BANDWIDTH I S = 2mA Typical, Peaking.dB A V R L R F R G (MHz) 3dB BW V S = ±V, R S/D = Ω dB BW (MHz) A V R L R F R G (MHz) 3dB BW, R S/D = Ω k dB BW (MHz) I S = ma Typical, Peaking.dB A V R L R F R G (MHz) 3dB BW V S = ±V, R S/D =.2k dB BW (MHz) A V R L R F R G (MHz) 3dB BW, R S/D = 6.k k dB BW (MHz) I S = ma Typical, Peaking.dB A V R L R F R G (MHz) 3dB BW V S = ±V, R S/D = 22.k dB BW (MHz) A V R L R F R G (MHz) 3dB BW, R S/D = 2k k k dB BW (MHz)

5 TYPICAL PERFORMANCE CHARACTERISTICS LT26 3dB BANDWIDTH (MHz) Bandwidth vs Supply Voltage PEAKING.dB PEAKING db R F = 7Ω R F = 6Ω A V = 2 R L = Ω R F = 68Ω R F = 7Ω R F =.k R F = k SUPPLY VOLTAGE (±V) LT26 TPC 3dB BANDWIDTH (MHz) 2 Bandwidth vs Supply Voltage PEAKING.dB PEAKING db R F = 6Ω R F = 7Ω R F = k R F = 2k A V = 2 R L = Ω SUPPLY VOLTAGE (±V) LT26 TPC2 FEEDBACK RESISTOR (Ω) k k Bandwidth and Feedback Resistance vs Capacitive Load for.db Peak BANDWIDTH FEEDBACK RESISTOR A V = 2 R L = C COMP =.µf CAPACITIVE LOAD (pf) LT26 TPC3 3dB BANDWIDTH (MHz) 3dB BANDWIDTH (MHz) Bandwidth vs Supply Voltage PEAKING.dB PEAKING db R F =39Ω A V = R L = Ω R F = 3Ω R F = 7Ω R F = 68Ω R F =.k SUPPLY VOLTAGE (±V) 3dB BANDWIDTH (MHz) 2 Bandwidth vs Supply Voltage PEAKING.dB PEAKING db A V = R L = Ω R F = 6Ω R F = 68Ω R F = k R F =.k SUPPLY VOLTAGE (±V) FEEDBACK RESISTOR (Ω) k k Bandwidth and Feedback Resistance vs Capacitive Load for db Peak BANDWIDTH A FEEDBACK RESISTOR V = 2 R L = C COMP =.µf k k CAPACITIVE LOAD (pf) 3dB BANDWIDTH (MHz) LT26 TPC LT26 TPC LT26 TPC6 DIFFERENTIAL PHASE (DEG) Differential Phase vs Supply Voltage R F = R G = 6Ω A V = 2 N PACKAGE SUPPLY VOLTAGE (±V) R L = Ω R L = Ω R L = Ω R L = Ω LT26 TPC7 DIFFERENTIAL GAIN (%) Differential Gain vs Supply Voltage R L = Ω R L = Ω R L = Ω R L = Ω SUPPLY VOLTAGE (±V) R F = R G = 6Ω A V = 2 N PACKAGE LT26 TPC8 SPOT NOISE (nv/ Hz OR pa/ Hz) Spot Noise Voltage and Current vs Frequency i n e n i n k k k FREQUENCY (Hz) LT26 TPC9

6 LT26 TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage 2 V S/D = V T 22 J = C 2 2 Supply Current vs Ambient Temperature, V S = ±V R SD = Ω A V = R L = N PACKAGE 2 2 Supply Current vs Ambient Temperature, R SD = Ω A V = R L = N PACKAGE SUPPLY CURRENT (ma) T J = 2 C T J = 8 C T J = 2 C SUPPLY CURRENT (ma) R SD =.2k R SD = 22.k SUPPLY CURRENT (ma) R SD = 6.k R SD = 2k SUPPLY VOLTAGE (±V) TEMPERATURE ( C) TEMPERATURE ( C) LT26 TPC LT26 TPC LT26 TPC2 SUPPLY CURRENT (ma) Supply Current vs Shutdown Pin Current 2 SHUTDOWN PIN CURRENT (µa) COMMON-MODE RANGE (V) V V Input Common Mode Limit vs Junction Temperature TEMPERATURE ( C) OUTPUT SHORT-CIRCUIT CURRENT (A) Output Short-Circuit Current vs Junction Temperature SOURCING SINKING TEMPERATURE ( C) LT26 TPC3 LT26 TPC LT26 TPC OUTPUT SATURATION VOLTAGE (V) V Output Saturation Voltage vs Junction Temperature R L = 2k R L = Ω R L = Ω R L = 2k POWER SUPPLY REJECTION (db) Power Supply Rejection Ratio vs Frequency NEGATIVE POSITIVE R L = Ω R F = R G = k SUPPLY CURRENT (ma) 6 2 Supply Current vs Large-Signal Output Frequency (No Load) A V = 2 R L = V OUT = 2V P-P V TEMPERATURE ( C) LT26 TPC6 k k M M M FREQUENCY (Hz) LT26 TPC7 k k M M FREQUENCY (Hz) LT26 TPC8 6

7 TYPICAL PERFORMANCE CHARACTERISTICS LT26 OUTPUT IMPEDANCE (Ω). Output Impedance vs Frequency I O = ma R S/D = 2k R S/D = Ω OUTPUT IMPEDANCE (Ω) k k k Output Impedance in Shutdown vs Frequency A V = R F = k DISTORTION (dbc) nd and 3rd Harmonic Distortion vs Frequency V O = 2V P-P R L = Ω R L = Ω 2nd 3rd 2nd 3rd. k M M M FREQUENCY (Hz) LT26 TPC9 k M M M FREQUENCY (Hz) LT26 TPC FREQUENCY (MHz) LT26 TPC2 3rd ORDER INTERCEPT (dbm) 6 2 3rd Order Intercept vs Frequency R L = Ω R F = 9Ω R G = 6.9Ω Test Circuit for 3rd Order Intercept LT26 P O 9Ω 6Ω Ω MEASURE INTERCEPT AT P O LT26 TPC23 2 FREQUENCY (MHz) 2 LT26 TPC22 7

8 LT26 SIMPLIFIED SCHEMATIC V TO ALL CURRENT SOURCES Q Q Q2 D Q Q8 Q Q6 Q Q7.2k IN V IN Q9 V Ω C C R C COMP OUTPUT SHUTDOWN V V Q2 Q3 Q8 Q6 Q Q D2 Q7 Q3 V LT26 SS APPLICATIONS INFORMATION The LT26 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 impedance and the desired flatness of response. The Typical AC Performance tables give the values which result in the highest.db and.db bandwidths for various resistive 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 db. These curves use a solid line when the response has less than.db of peaking and a dashed 8 line when the response has.db to db of peaking. The curves stop where the response has more than db of peaking. For resistive loads, the COMP pin should be left open (see section on capacitive loads). Capacitive Loads The LT26 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 fl attened. Figure shows the effect of the network on a 2pF load. Without the optional compensation, there is a db peak at MHz caused by the effect of the capacitance on the output stage. Adding a.µf 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 in a response which

9 LT26 APPLICATIONS INFORMATION VOLTAGE GAIN (db) R F =.2k COMPENSATION R F = 2k NO COMPENSATION R F = 2k COMPENSATION FREQUENCY (MHz) Figure LT26 F is flat to.3db to MHz. The network has the greatest effect for C L in the range of pf to pf. 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.db and db 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 capacitance. Also shown is the 3dB bandwidth with the suggested 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 Ω load, the bandwidth drops from MHz to 3MHz when the compensation is connected. Hence, the compensation was made optional. To disconnect the optional compensation, leave the COMP pin open. capacitor and the supply current is typically µa. The shutdown pin is referenced to the positive supply through an internal bias circuit (see the simplified schematic). An easy way to force shutdown is to use open drain (collector) logic. The circuit shown in Figure 2 uses a 7C9 buffer to interface between V logic and the LT26. The switching time between the active and shutdown states is less than µs. A 2k pull-up resistor speeds up the turn-off time and insures that the LT26 is completely turned off. Because the pin is referenced to the positive supply, the logic used should have a breakdown voltage of greater than the positive supply voltage. No other circuitry is necessary as the internal circuit limits the shutdown pin current to about µa. Figure 3 shows the resulting waveforms. ENABLE V IN V 7C96 LT26 S/D V V R F V 2k LT26 F2 Figure 2. Shutdown Interface R G V OUT Shutdown/Current Set If the shutdown feature is not used, the SHUTDOWN pin must be connected to ground or V. The shutdown pin can be used to either turn off the biasing for the amplifier, reducing the quiescent current to less than 2µA, or to control the quiescent current in normal operation. The total bias current in the LT26 is controlled by the current fl owing out of the shutdown pin. When the shutdown pin is open or driven to the positive supply, the part is shut down. In the shutdown mode, the output looks like a pf V OUT ENABLE A V = R F = 82Ω R L = Ω R PU = 2k V IN = V P-P µs/div Figure 3. Shutdown Operation 26 F3 9

10 LT26 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 times the current in the shutdown pin. The voltage across the resistor in this condition is V 3V BE. For example, a 6k resistor will set the quiescent supply current to ma with. The photos (Figures a and b) show the effect of reducing the quiescent supply current on the large-signal response. The quiescent current can be reduced to ma in the inverting configuration without much change in response. In noninverting mode, however, the slew rate is reduced as the quiescent current is reduced. Slew Rate Unlike a traditional op amp, the slew rate of a current feedback amplifier is not independent of the amplifier gain confi guration. 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 a, b and c) show the large-signal response of the LT26 for various gain configurations. The slew rate varies from 86V/µs for a gain of, to V/µs for a gain of. R F = 7Ω R L = Ω I Q = ma, ma, 2mA ns/div 26 Fa Figure a. Large-Signal Response vs I Q, A V = R F = 82Ω R L = Ω 2ns/DIV 26 Fa Figure a. Large-Signal Response, A V = R F = 7Ω R L = Ω I Q = ma, ma, 2mA ns/div 26 Fb Figure b. Large-Signal Response vs I Q, A V = 2 R F = R G = 7Ω R L = Ω 2ns/DIV 26 Fb Figure a. Large-Signal Response, A V =

11 LT26 APPLICATIONS INFORMATION R F = 7Ω R L = Ω 2ns/DIV Figure c. Large-Signal Response, A V = 2 When the LT26 is used to drive capacitive loads, the available output current can limit the overall slew rate. In the fastest configuration, the LT26 is capable of a slew rate of over V/ns. The current required to slew a capacitor at this rate is ma per picofarad of capacitance, so,pf would require A! The photo (Figure 6) shows the large signal behavior with C L =,pf. The slew rate is about 6V/µs, determined by the current limit of 6mA. R L = R G = 3k R L = ns/div 26 Fc 26 TA2 Figure 6. Large-Signal Response, C L =,pf 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 input signal be less than ±V when the device is shut down. Capacitance on the Inverting Input Current feedback amplifiers require resistive feedback from the output to the inverting input for stable operation. Take care to minimize the stray capacitance between the output and the inverting input. Capacitance on the inverting 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 amplifi er. Power Supplies The LT26 will operate from single or split supplies from ±V (V total) to ±V (V 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 µv per volt of supply mismatch. The inverting bias current can change as much as µa per volt of supply mismatch, though typically the change is less than.µa per volt. Thermal Considerations The LT26 contains a thermal shutdown feature which protects against excessive internal (junction) temperature. If the junction temperature of the device exceeds the protection threshold, the device will begin cycling between normal operation and an off state. The cycling is not harmful to the part. The thermal cycling occurs at a slow rate, typically ms to several seconds, which depends on the power dissipation and the thermal time constants of the package and heat sinking. Raising the ambient temperature 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 electrically 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

12 LT26 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 stiffeners and plated through holes can also be used to spread the heat generated by the device. Tables and 2 list thermal resistance for each package. For the TO-22 package, thermal resistance is given for junction-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- board with oz copper. This data can be used as a rough guideline in estimating thermal resistance. The thermal resistance for each application will be affected by thermal interactions with other components as well as board size and shape. Table. R Package, 7-Lead DD COPPER AREA THERMAL RESISTANCE TOPSIDE* BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT) 2 sq. mm 2 sq. mm 2 sq. mm 2 C/W sq. mm 2 sq. mm 2 sq. mm 27 C/W 2 sq. mm 2 sq. mm 2 sq. mm 3 C/W *Tab of device attached to topside copper Table 2. S8 Package, 8-Lead Plastic SO COPPER AREA THERMAL RESISTANCE TOPSIDE* BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT) 2 sq. mm 2 sq. mm 2 sq. mm 6 C/W sq. mm 2 sq. mm 2 sq. mm 62 C/W 22 sq. mm 2 sq. mm 2 sq. mm 6 C/W sq. mm 2 sq. mm 2 sq. mm 69 C/W sq. mm sq. mm 2 sq. mm 73 C/W sq. mm 22 sq. mm 2 sq. mm 8 C/W sq. mm sq. mm 2 sq. mm 83 C/W *Pins and 2 attached to topside copper Y Package, 7-Lead TO-22 Thermal Resistance (Junction-to-Case) = C/W N8 Package, 8-Lead DIP Thermal Resistance (Junction-to-Ambient) = C/W 2 Calculating Junction Temperature The junction temperature can be calculated from the equation: T J = (P D θ JA ) T A where: T J = Junction Temperature T A = Ambient Temperature P D = Device Dissipation θ JA = Thermal Resistance (Junction-to Ambient) As an example, calculate the junction temperature for the circuit in Figure 7 for the N8, S8, and R packages assuming a 7 C ambient temperature. 3Ω V I LT26 S/D V 39mA.µF 2k 2k pf LT26 F7 Figure 7. Thermal Calculation Example f = 2MHz 2V 2V 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. Then: P D = (39mA V) (2V) 2 /(2k 2k) =.3W T J = (.3W C/W) 7 C = 73 C for the N8 package T J = (.3W 6 C/W) 7 C = 37 C for the S8 with 22 sq. mm topside heat sinking T J = (.3W 3 C/W) 7 C = 6 C for the R package with sq. mm topside heat sinking Since the Maximum Junction Temperature is C, the N8 package is clearly unacceptable. Both the S8 and R packages are usable.

13 TYPICAL APPLICATIONS Precision Hi Current Amplifi er CMOS Logic to Shutdown Interface LT26 V IN LT97 pf LT26 COMP S/D.µF OUT V LT26 S/D 2k 3Ω 3k k V k V 2N39 LT26 TA OUTPUT OFFSET: < µv SLEW RATE: 2V/µs BANDWIDTH: MHz STABLE WITH C L < nf k LT26 TA3 Low Noise Buffered Line Driver Distribution Amplifi er V µf LT µf V µf LT26 S/D.µF OUTPUT R L V IN 7Ω LT26 S/D R F 7Ω 7Ω 7Ω CABLE LT26 TA6 7Ω V 68pF µf R G 7Ω 6Ω V 6Ω 99Ω Ω LT26 TA R L = 32Ω V O = V RMS THD NOISE =.9% AT khz =.% AT 2kHz SMALL SIGNAL.dB BANDWIDTH = 6kHz Buffer A V = V IN LT26 COMP S/D.µF* R F ** V OUT * OPTIONAL, USE WITH CAPACITIVE LOADS ** VALUE OF R F DEPENDS ON SUPPLY VOLTAGE AND LOADING. SELECT FROM TYPICAL AC PERFORMANCE TABLE OR DETERMINE EMPIRICALLY LT26 TA7 3

14 LT26 PACKAGE DESCRIPTION..32 ( ) N8 Package 8-Lead PDIP (Narrow. Inch) (Reference LTC DWG # -8-)..6 (.3.6). ±. (3.2 ±.27).* (.6) MAX (.23.38) ( ).6 (.6) TYP. (2.) BSC.2 (3.8) MIN.8 ±.3 (.7 ±.76).2 (.8) MIN.2 ±.* (6.77 ±.38) 2 3 N8 2 NOTE: INCHES. DIMENSIONS ARE MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED. INCH (.2mm) R Package 7-Lead Plastic DD Pak (Reference LTC DWG # -8-62).26 (6.2).6 (.2).6 (.2) TYP.39. (9.96.) TYP.6.8 (.9.72).. (.3.397).6 (.2).83 (.68).3.37 ( ).9 (.99) TYP..8. ( ).7 (.9).9. ( ). (7.62) BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK ( ). (.27).26.3 BSC ( ) TYP.3.23 (.3.8). ±.2 (.27 ±.) R (DD7) RECOMMENDED SOLDER PAD LAYOUT NOTE:. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS

15 PACKAGE DESCRIPTION S8 Package 8-Lead Plastic Small Outline (Narrow. Inch) (Reference LTC DWG # -8-6) LT26. BSC. ± (.8.) NOTE MIN.6 ± ( )..7 ( ) NOTE 3. ±. TYP RECOMMENDED SOLDER PAD LAYOUT (.23.2)..2 (.2.8) 8 TYP.3.69 (.36.72).. (..2).6. (.6.27) NOTE: INCHES. DIMENSIONS IN (MILLIMETERS)..9 (.3.83) TYP 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED.6" (.mm). (.27) BSC SO8 3 T7 Package 7-Lead Plastic TO-22 (Standard) (Reference LTC DWG # -8-22).39. (9.96.).7. ( ) DIA.6.8 (.9.72).. (.3.397).2.27 ( ).6. ( ).3.37 ( ).7.62 (.78.78).62 (.7) TYP ( ) SEATING PLANE (3.86.) ( ).9. ( )..9* ( ). BSC (.27) (.66.9).3.6 (3.29.9) Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights (.3.8) *MEASURED AT THE SEATING PLANE T7 (TO-22) 8

16 LT26 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT High Speed Buffer High Power, High Speed Buffer LT27 Dual 2mA Out, 9V/µs, 6MHz Current Feedback Amplifier Adjustable Supply Current, Shutdown LT2.A, 3MHz, 9V/µs Current Feedback Amplifi er Adjustable Supply Current, Shutdown LT39 Single MHz Current Feedback Amplifi er.db Gain Flatness to MHz LT8 6.mA, 22MHz,.V/ns Operational Amplifi er with S6 Version Features Programmable Supply Current Programmable Current LT88 MHz, 2V/µs, 9mA Single Operational Amplifi er High Speed, Low Noise, Low Distortion, Low Offset 6 LT 7 REV A PRINTED IN USA Linear Technology Corporation 6 McCarthy Blvd., Milpitas, CA (8) 32-9 FAX: (8) LINEAR TECHNOLOGY CORPORATION 993