LM6313 High Speed, High Power Operational Amplifier General Description Features The LM6313 is a high-speed, high-power operational amplifier. This operational amplifier features a 35 MHz small signal bandwidth, and 250 V/ms slew rate. A compensation pin is included for adjusting the open loop bandwidth. The input stage (A1) and output stage (A2) are pinned out separately, and can be used independently. The operational amplifier is designed for low impedance loads and will deliver g 300 mA. The LM6313 has both overcurrent and thermal shutdown protection with an error flag to signal both these fault conditions. These amplifiers are built with National’s VIPTM (Vertically Integrated PNP) process which provides fast PNP transistors that are true complements to the already fast NPN devices. This advanced junction-isolated process delivers high speed performance without the need for complex and expensive dielectric isolation. Y Y Y Y Y Y Y Y Applications Y Y Y Y Y Y Connection Diagram High slew rate 250 V/ms Wide bandwidth 35 MHz g 300 mA Peak output current Input and output stages pinned out separately Single or dual supply operation Thermal protection Error flag warns of faults g 5V to g 15V Wide supply voltage range High speed ATE pin driver Data acquisition Driving capacitive loads Flash A-D input driver Precision 50X –75X video line driver Laser diode driver Typical Application Dual-In-Line Package TL/H/10521 – 2 TL/H/10521 – 1 Top View Order Number LM6313N See NS Package Number N16A *Heat sink pins See Note 5 and Applications. **Do not ground or otherwise connect to this pin. VIPTM is a trademark of National Semiconductor Corporation. C1995 National Semiconductor Corporation TL/H/10521 RRD-B30M75/Printed in U. S. A. LM6313 High Speed, High Power Operational Amplifier February 1995 Absolute Maximum Ratings (Note 1) Total Supply Voltage ( a VS to bVS) A1 Differential Input Voltage (Note 2) A1 Input Voltage A2 Input to Output Voltage A2 Input Voltage Flag Output Voltage Short-Circuit to Ground Storage Temperature Range Lead Temperature (Soldering, 5 seconds) 36V ( g 18) g 7V ESD Tolerance (Note 4) Pins 10 and 11 All Other Pins (V a b0.7) to (Vb b7V) g 7V g VS GND to a VS (Note 3) b 65§ C s T s a 150§ C 260§ C g 600V g 1500V Operating Temperature Range LM6313N 0§ C to 70§ C Thermal Derating Information (Note 5) iJA TJ (Max) 40§ C/W 125§ C Operational Amplifier DC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. VCM e 0V, RS e 50X, the circuit configured as in Figure 1 . Symbol Parameter Conditions Typical 25§ C Limit 0§ C to 70§ C Limit Units 20 22 mV (Max) VOS Input Offset Voltage 5 DVOS/DT Average Input Offset Voltage Drift 10 Ib Input Bias Current 2 5 7 mA (Max) IOS Input Offset Current 0.15 1.5 1.9 mA (Max) DIOS/DT Average Input Offset Current Drift 0.4 nA/§ C RIN Input Resistance Differential 325 kX CIN Input Capacitance AV e a 1, f e 10 MHz 2.2 VCM Common-Mode Voltage Range AV1 AV2 Voltage Gain 1 Voltage Gain 2 RL e 1 kX, VO e g 10V RL e 50X, VO e g 8V CMRR Common-Mode Rejection Ratio b 10V s VCM s a 10V PSRR Power Supply Rejection Ratio g 5V s VS s g 16V VO1 VO2 VO3 Output Voltage Swing 1 Output Voltage Swing 2 Output Voltage Swing 3 IS Supply Current ISC Peak Short-Circuit Output mV/§ C pF a 14.2 b 13.2 a 13.8 b 12.8 a 13.7 b 12.7 V (Min) 6000 5000 2500 2000 2000 1500 V/V (Min) 90 72 70 dB (Min) 90 72 70 dB (Min) RL e 1 kX RL e 100X RL e 50X 13.1 12.0 11.0 11.8 10.5 9.0 11.2 10.0 8.5 g V (Min) TJ e 0§ C TJ e 25§ C TJ e 125§ C 18 23 (See Figure 3 ) 300 24 mA (Max) 21 TL/H/10521 – 3 FIGURE 1 2 mA Electrical Characteristics (Continued) Operational Amplifier AC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. VCM e 0V, RS e 50X, the circuit configured as in Figure 1 . Symbol Parameter Conditions Typical GBW Gain-Bandwidth Product @ f e 30 MHz SR Slew Rate AV e b1, RL e 50X (Note 6) Units 35 MHz 250 V/ms PBW Power Bandwidth VOUT e 20 VPP 3.0 MHz tS Settling Time 10V Step to 0.1% (See Figure 2 ) 200 ns Phase Margin AV e b1, RL e 1 kX, CL e 50 pF 53 Deg en in Differential Gain 0.1 % Differential Phase 0.1 Deg Input Noise Voltage f e 10 kHz 14 nV/ SHz Input Noise Current f e 10 kHz 1.8 pA/ SHz A1 DC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. VCM e 0V, RS e 50X. Parameter Conditions Typical 25§ C Limit 0§ C to 70§ C Limit Units AVOL Large Signal Voltage Gain VOUT e g 10V, RL e 2 kX VOUT e g 10V, RL e % 650 6000 300 2500 250 2000 V/V (Min) CMRR Common-Mode Rejection Ratio b 10V s VCM s a 10V 90 72 70 dB (Min) PSRR Power Supply Rejection Ratio g 5V s g VS s a 16V 90 72 70 dB (Min) ISC Output Short Circuit Current g 60 g 30 g 25 mA (Min) Symbol A1 AC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. RS e 50X. Symbol Parameter Conditions Typical 25§ C Limit Units GBW Gain-Bandwidth f e 30 MHz 37 25 MHz (Min) SR Slew Rate AV e a 1, RL e 100 kX, g 4 VIN, g 2 VOUT 250 150 V/ms (Min) Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test condition listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. Note 2: In order to achieve optimum AC performance, the input stage was designed without protective clamps. Exceeding the maximum differential input voltage results in reverse breakdown of the base-emitter junction of one of the input transistors. Degradation of the input parameters (especially VOS, IOS, and Noise) is proportional to the level of the externally limited breakdown current and the accumulated duration of the breakdown condition. Note 3: Continuous short-circuit operation of A1 at elevated temperature can result in exceeding the maximum allowed junction temperature of 125§ C. A2 contains current limit and thermal shutdown to protect against fault conditions. The device may be damaged by shorts to the supplies. Note 4: Human body model, C e 100 pF, RS e 1500X. 3 Electrical Characteristics (Continued) A2 DC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. RS e 50X. Symbol Parameter Conditions Typical 25§ C Limit 0§ C to 70§ C Limit Units AV1 Voltage Gain 1 RL e 1 kX, VIN e g 10V 0.99 0.97 0.95 V/mV (Min) AV2 Voltage Gain 2 RL e 50X, VIN e g 10V 0.9 0.85 0.82 V/V (Min) VOS Offset Voltage RL e 1 kX 15 70 100 mV (Max) Ib Input Bias Current RL e 1 kX, RS e 10 kX 1 6 8 mA (Max) RIN Input Resistance RL e 50X 5 CIN Input Capacitance RO Output Resistance IOUT e g 10 mA 3.5 5.0 8.0 X (Min) VO Voltage Output Swing RL e 1 kX RL e 100X RL e 50X 13.7 12.5 11.0 13.0 10.5 9.0 12.7 10.0 8.5 V (Min) 70 60 50 dB (Min) PSRR Power Supply Rejection Ratio MX 3.5 VS e g 5V to g 16V pF A2 AC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. RS e 50X. Symbol Parameter 25§ C Limit Conditions Typical 1200 750 550 30 Units SR 1 SR 2 Slew Rate 1 Slew Rate 2 VIN e g 11V, RL e 1 kX VIN e g 11V, RL e 50X (Note 7) BW b 3 dB Bandwidth VIN e g 100 mVpp RL e 50X, CL s 10 pF 65 tr, tf Rise Time Fall Time RL e 1 kX, CL s 10 pF VO e 100 mVpp 8 ns PD Propagation Delay RL e 50X, CL s 10 pF VO e 100 mVpp 4 ns Overshoot RL e 1 kX, CL e 100 pF RL e 50X, CL e 1000 pF 13 21 % V/ms (Min) MHz (Min) Additional (A2) Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA e 25§ C, and Supply Voltage VS e g 15V. Boldface limits apply at temperature extremes. Symbol Parameter Conditions Typical 25§ C Limit 0§ C to 70§ C Limit Units VOL Flag Pin Output Low Voltage ISINK Flag Pin e 500 mA 220 340 400 mV (Max) IOH Flag Pin Output High Current VOH Flag Pin e 15V (Note 8) 0.01 10 20 mA (Max) Note 5: For operation at elevated temperature, these devices must be derated to insure TJ s 125§ C. TJ e TA a (PD c iJA). iJA for the N package mounted flush to the PCB, is 40§ C/W when pins 4, 5, 12 and 13 are soldered to a total of 2 in2 of copper trace. Note 6: Measured between g 5V. Note 7: VIN e g 9V step input, measured between g 5V out. Note 8: The error flag is set during current limit or thermal shut-down. The flag is an open collector, low on fault. 4 Simplified Schematic TL/H/10521 – 4 Settling Time Test Circuit TL/H/10521 – 6 FIGURE 3 TL/H/10521 – 5 FIGURE 2 Protection Circuit Block Diagram TL/H/10521 – 7 5 Typical Performance Characteristics Op Amp (Unless otherwise specified, TA e 25§ C, VS e g 15V, and RL e 10 kX.) Slew Rate vs Capacitive Load Bode Plot Output Resistance (Open Loop) Bias Current vs Common-Mode Voltage Supply Current vs Supply Voltage Power Supply Rejection Input Noise Voltage Input Noise Current Slew Rate vs Compensation Gain-Bandwidth, Phase Margin vs Comp Cap and Load Cap CMR vs Frequency GBW and Phase Margin vs Comp Cap TL/H/10521 – 8 6 Typical Performance Characteristics A1 Only Gain vs Supply Voltage Bode Plot Gain-Bandwidth and Phase Margin vs Load Capacity Output Saturation Voltage Common-Mode Input Saturation Voltage Output Resistance (Open Loop) (Unless otherwise specified, TA e 25§ C, VS e g 15V, and RL e 10 kX.) TL/H/10521 – 9 Typical Performance Characteristics A2 Only (Unless otherwise specified, TA e 25§ C and VS e g 15V.) Slew Rate vs Supply Voltage Slew Rate vs Input Amplitude Slew Rate vs Temperature Bandwidth vs Supply Voltage Overshoot vs Capacitive Load Gain and Phase Shift (RL e 50X) TL/H/10521 – 10 7 Application Hints The LM6313 is a high-speed, high power operational amplifier that is designed for driving low-impedance loads such as 50X and 75X cables. Available in the standard, low cost, 16-pin DIP, this amplifier will drive back terminated video cables with up to 10 Vp-p. The ability to add additional compensation allows the LM6313 to drive capacitive loads of any size at bandwidths previously possible only with very expensive hybrid devices. The LM6313 is excellent for driving high-speed flash A-to-D converters that require low-impedance drive at high frequencies. At 1 MHz, when used as a buffer, the LM6313 output impedance is below 0.1X. This very low output impedance also means that cables can be accurately backterminated by just placing the characteristic impedance in series with the LM6313 output. SUPPLY BYPASSING Because of the large currents required to drive low-impedance loads, supply bypassing as close as possible to the I.C. is important. At 50 MHz, a few inches of wire or circuit trace can have 20X or 30X of inductive reactance. This inductance in series with a 0.1 mF bypass capacitor can resonate at 1 MHz to 2 MHz and just appear as an inductor at higher frequencies. A 0.1 mF and a 10mF to 15 mF capacitor connected in parallel and as close as possible to the LM6313 supply pins, from each supply to ground, will give best performance. SELECTION OF COMPENSATION CAPACITOR The compensation pin, pin 15, makes it possible to drive any load at any closed loop gain without stability problems. In most cases, where the gain is b1 or greater and the load is resistive, no compensation capacitor is required. When used at unity gain or when driving reactive loads, a small capacitor of 5 pF to 20 pF will insure optimum performance. The easiest way to determine the best value of compensation capacitor is to temporarily connect a trimmer capacitor (typical range of 2 pF to 15 pF) between pin 15, and ground, and adjust it for little or no overshoot at the output while driving the input with a square wave. If the actual load capacitance is known, the typical graphs ‘‘Gain-Bandwidth and Phase Margin vs. Load Capacitance’’ can be used to select a value. OVER-VOLTAGE PROTECTION If the LM6313 is being operated on supply voltages of greater than g 5V, the possibility of damaging the output stage transistors exists. At higher supply voltages, if the output is shorted or excessive power dissipation causes the output stage to shut down, the maximum A2 input-to-output voltage, can be exceeded. This occurs when the input stage tries to drive the output while the output is at ground. To prevent this from happening, an easy solution is to place diodes around the output stage (See Figure 4 ). This will limit the maximum differential voltage to about 1.3V. Any signal diode, such as the 1N914 or the 1N4148 will work fine. VIDEO CABLE DRIVER The LM6313 is ideally suited for driving 50X or 75X cables. Unlike a buffer that requires a separate gain stage to make up for the losses involved in termination, the LM6313 gain can be set to 1 plus the line losses when the transmission line is end-terminated. If back-termination is needed, adding the line impedance in series with the output and raising the gain to 2 plus the expected line losses will provide a 0 dB loss system. Figure 5 illustrates the back and end terminated video system including compensation for line losses. The excellent stability of the LM6313 with changes in supply voltages allow running the amplifier on unregulated supplies. The typical change in phase shift when the supplies are changed from g 5V to g 15V is less than 3§ at 10 MHz. TL/H/10521 – 11 FIGURE 4 HEAT SINKING When driving a low impedance load such as 50X, and operating from g 15V supplies, the internal power dissipation of the LM6313 can rise above 3W. To prevent overheating of the chip, which would cause the thermal protection circuitry to shut the system down, the following guidelines should be followed: 1. Reduce the supply voltage. The LM6313 will operate with little change in performance, except output voltage swing, on g 5V supplies. This will reduce the dissipation to the level where no precautions against overheating are necessary for loads of 10X or more. 2. Solder pins 4, 5, 12 and 13 to copper traces which are at least 0.100 inch wide and have a total area of at least 2 square inches, to obtain a iJA of 40§ C/W. These four pins are connected to the back of the chip and will be at Vb. They should not be used as a Vb connection unless pin 3 is also connected to this same point. TL/H/10521 – 12 FIGURE 5 8 Application Hints (Continued) CAPACITIVE LOAD DRIVING Figure 7 is the circuit used to demonstrate the ability of the LM6313 to drive capacitive loads at speeds not previously possible with monolithic op amps. LASER DIODE MODULATOR Figure 6 is a minimum component count example of a video modulator for a CW laser diode. This example biases the diode at 200 mA and modulates the current at g 200 mA per volt of signal. If it is desired to reduce power consumption and g 5V supplies are available, all that is necessary is to change R2 to 5 kX and R4 to 15X. TL/H/10521 – 14 FIGURE 7 TL/H/10521 – 13 FIGURE 6 In photo 2, CL is changed to 1 mF. Under these conditions, the op amp is forced into current limiting. Here the current is internally limited to about g 400 mA. Note the rapid and complete recovery to normal operation at the end of slewing. In photo 1, CL is 1000 pF. The LM6313 is slewing at 250 V/ms, from b5V to a 5V. The slew rate is 450 V/ms from a 5V to b5V. This requires the op amp to deliver 450 mA into the load and remain stable. TL/H/10521 – 16 TL/H/10521 – 15 Photo 1 Photo 2 9 LM6313 High Speed, High Power Operational Amplifier Physical Dimensions inches (millimeters) Lit. Ý 108290 16-Lead Molded Dual-In-Line Package (N) Order Number LM6313N NS Package Number N16A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 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