EL2480 ® Data Sheet May 23, 2005 250MHz/3mA Current Mode Feedback Amplifier Features • Quad topology The EL2480 is a quad current-feedback operational amplifier which achieves a -3dB bandwidth of 250MHz at a gain of +1 while consuming only 3mA of supply current per amplifier. It will operate with dual supplies ranging from ±1.5V to ±6V, or from single supplies ranging from +3V to +12V. In spite of its low supply current, the EL2480 can output 55mA while swinging to ±4V on ±5V supplies. These attributes make the EL2480 an excellent choice for low power and/or low voltage cable-driver, HDSL, or RGB applications. For triple applications with disable, consider the EL2386 (16pin triple). PACKAGE TAPE & REEL PKG. DWG. # EL2480CS 14-Pin SO - MDP0027 EL2480CS-T7 14-Pin SO 7” MDP0027 EL2480CS-T13 14-Pin SO 13” MDP0027 EL2480CSZ (See Note) 14-Pin SO (Pb-free) - MDP0027 EL2480CSZ-T7 (See Note) 14-Pin SO (Pb-free) 7” MDP0027 EL2480CSZ-T13 (See Note) 14-Pin SO (Pb-free) 13” MDP0027 • 250MHz -3dB bandwidth • Low cost • Single- and dual-supply operation down to ±1.5V • 0.05%/0.05° diff. gain/diff. phase into 150Ω • 1200V/µs slew rate • Large output drive current - 55mA • Also available with disable in triple Applications • Low power/battery applications • HDSL amplifiers • Video amplifiers • Cable drivers • RGB amplifiers NOTE: Intersil Pb-free products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 1 • 3mA supply current (per amplifier) • Pb-Free plus Anneal available (RoHS compliant) Ordering Information PART NUMBER FN7055.1 • Test equipment amplifiers • Current to voltage converters Pinout EL2480 (14-PIN SO) TOP VIEW CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-352-6832 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2002, 2003, 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. EL2480 Absolute Maximum Ratings (TA = 25°C) Supply Voltage between VS+ and GND. . . . . . . . . . . . . . . . . +12.6V Voltage between VS+ and VS- . . . . . . . . . . . . . . . . . . . . . . . . +12.6V Common-Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . VS- to VS+ Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±6V Current into +IN or -IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±7.5mA Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . See Curves Operating Ambient Temperature Range . . . . . . . . . .-40°C to +85°C Operating Junction Temperature Plastic Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±60mA Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA DC Electrical Specifications PARAMETER VS = ±5V, RL = 150Ω, TA = 25°C unless otherwise specified DESCRIPTION VOS Input Offset Voltage TCVOS Average Input Offset Voltage Drift dVOS CONDITIONS MIN Measured from TMIN to TMAX TYP MAX UNIT 2.5 10 mV 5 µV/°C VOS Matching 0.5 mV +IIN +Input Current 1.5 d+IIN +IIN Matching 20 -IIN -Input Current 16 d-IIN -IIN Matching 2 µA CMRR Common Mode Rejection Ratio VCM = ±3.5V 50 dB -ICMR -Input Current Common Mode Rejection VCM = ±3.5V PSRR Power Supply Rejection Ratio VS is moved from ±4V to ±6V -IPSR - Input Current Power Supply Rejection VS is moved from ±4V to ±6V ROL Transimpedance VOUT = ±2.5V 120 300 kΩ +RIN +Input Resistance VCM = ±3.5V 0.5 2 MΩ +CIN +Input Capacitance 1.2 pF CMIR Common Mode Input Range ±3.5 ±4.0 V VO Output Voltage Swing ±3.5 ±4.0 V VS = 5 single-supply, high 4.0 V VS = 5 single-supply, low 0.3 V 55 mA VS = ±5 IO Output Current Per amplifier IS Supply Current Per amplifier 2 45 5 60 3 µA nA 40 30 70 1 50 15 µA µA/V dB 15 6 µA/V mA EL2480 AC Electrical Specifications PARAMETER VS = ±5V, RF = RG = 750Ω, RL = 150Ω, TA = 25°C unless otherwise specified DESCRIPTION CONDITIONS MIN TYP MAX UNIT -3dB BW -3dB Bandwidth AV = 1 250 MHz -3dB BW -3dB Bandwidth AV = 2 180 MHz 0.1dB BW 0.1dB Bandwidth AV = 2 50 MHz SR Slew Rate VOUT = ±2.5V, AV = 2 1200 V/µs tR, tF Rise and Fall Time VOUT = ±500mV 1.5 ns tPD Propagation Delay VOUT = ±500mV 1.5 ns OS Overshoot VOUT = ±500mV 3.0 % tS 0.1% Settling VOUT = ±2.5V, AV = -1 15 ns dG Differential Gain AV = 2, RL = 150Ω (Note 1) 0.05 % dP Differential Phase AV = 2, RL = 150Ω (Note 1) 0.05 ° dG Differential Gain AV = 1, RL = 500Ω (Note 1) 0.01 % dP Differential Phase AV = 1, RL = 500Ω (Note 1) 0.01 ° CS Channel Separation f = 5MHz 85 dB NOTE: 1. DC offset from 0V to 0.714V, AC amplitude 286mVP-P, f = 3.58MHz 3 600 EL2480 Test Circuit (per Amplifier) Simplified Schematic (per Amplifier) 4 EL2480 Typical Performance Curves Non-Inverting Frequency Response (Gain) Non–Inverting Frequency Response (Phase) Inverting Frequency Response (Gain) Inverting Frequency Response (Phase) Frequency Response for Various RF and RG Frequency Response for Various RL and CL Ω Transimpedance (ROL) vs Frequency 5 PSRR and CMRR vs Frequency Frequency Response for Various CIN- EL2480 Typical Performance Curves (Continued) Voltage and Current Noise vs Frequency 2nd and 3rd Harmonic Distortion vs Frequency Output Voltage Swing vs Frequency -3dB Bandwidth and Peaking vs Supply Voltage for Various Non-Inverting Gains -3dB Bandwidth and Peaking vs Supply Voltage for Various Inverting Gains Output Voltage Swing vs Supply Voltage Supply Current vs Supply Voltage Common-Mode Input Range vs Supply Voltage Slew Rate vs Supply Voltage 6 EL2480 Typical Performance Curves (Continued) Input Bias Current vs Die Temperature Short-Circuit Current vs Die Temperature Transimpedance (ROL) vs Die Temperature -3dB Bandwidth and Peaking vs Die Temperature for Various Non-Inverting Gains -3dB Bandwidth vs Die Temperature for Various Inverting Gains Input Offset Voltage vs Die Temperature Supply Current vs Die Temperature Input Voltage Range vs Die Temperature Slew Rate vs Die Temperature 7 EL2480 Typical Performance Curves (Continued) Differential Gain and Phase vs DC Input Voltage at 3.58MHz Differential Gain and Phase vs DC Input Voltage at 3.58MHz Settling Time vs Settling Accuracy Channel Separation vs Frequency Large-Signal Step Response JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 1.6 1.420W 1.4 1.2 POWER DISSIPATION (W) POWER DISSIPATION (W) 1.8 Small-Signal Step Response SO14 1.2 θJA=88°C/W 1 0.8 0.6 0.4 0.2 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) 8 150 1.042W SO14 1 θJA=120°C/W 0.8 0.6 0.4 0.2 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) 150 EL2480 Applications Information Product Description The EL2480 is a current-feedback operational amplifier that offers a wide -3dB bandwidth of 250MHz and a low supply current of 3mA per amplifier. This product also features high output current drive. The EL2480 can output 55mA per amplifier. The EL2480 works with supply voltages ranging from a single 3V to ±6V, and it is also capable of swinging to within 1V of either supply on the input and the output. Because of its current-feedback topology, the EL2480 does not have the normal gain-bandwidth product associated with voltage-feedback operational amplifiers. This allows its -3dB bandwidth to remain relatively constant as closed-loop gain is increased. This combination of high bandwidth and low power, together with aggressive pricing make the EL2480 the ideal choice for many low-power/high-bandwidth applications such as portable computing, HDSL, and video processing. The EL2480 is available in the industry standard SO package. For triple application with disable, consider the EL2386 (16-pin triple). Power Supply Bypassing and Printed Circuit Board Layout As with any high-frequency device, good printed circuit board layout is necessary for optimum performance. Ground plane construction is highly recommended. Lead lengths should be as short as possible. The power supply pins must be well bypassed to reduce the risk of oscillation. The combination of a 4.7µF tantalum capacitor in parallel with a 0.1µF capacitor has been shown to work well when placed at each supply pin. For good AC performance, parasitic capacitance should be kept to a minimum especially at the inverting input (see the Capacitance at the Inverting Input section). Ground plane construction should be used, but it should be removed from the area near the inverting input to minimize any stray capacitance at that node. Carbon or Metal-Film resistors are acceptable with the Metal-Film resistors giving slightly less peaking and bandwidth because of their additional series inductance. Use of sockets, should be avoided if possible. Sockets add parasitic inductance and capacitance which will result in some additional peaking and overshoot. Capacitance at the Inverting Input Any manufacturer's high-speed voltage- or current-feedback amplifier can be affected by stray capacitance at the inverting input. For inverting gains this parasitic capacitance has little effect because the inverting input is a virtual ground, but for non-inverting gains this capacitance (in conjunction with the feedback and gain resistors) creates a pole in the feedback path of the amplifier. This pole, if low enough in frequency, has the same destabilizing effect as a zero in the forward open-loop response. The use of large 9 value feedback and gain resistors further exacerbates the problem by further lowering the pole frequency. The experienced user with a large amount of PC board layout experience may find in rare cases that the EL2480 has less bandwidth than expected. The reduction of feedback resistor values (or the addition of a very small amount of external capacitance at the inverting input, e.g. 0.5pF) will increase bandwidth as desired. Please see the curves for Frequency Response for Various RF and RG, and Frequency Response for Various CIN-. Feedback Resistor Values The EL2480 has been designed and specified at gains of +1 and +2 with RF = 750Ω. These values of feedback resistors give 250MHz of -3dB bandwidth at AV = +1 with about 2.5dB of peaking, and 180MHz of -3dB bandwidth at AV = +2 with about 0.1dB of peaking. Since the EL2480 is currentfeedback amplifier, it is also possible to change the value of RF to get more bandwidth. As seen in the curve of Frequency Response For Various RF and RG, bandwidth and peaking can be easily modified by varying the value of the feedback resistor. Because the EL2480 is current-feedback amplifier, its gainbandwidth product is not a constant for different closed-loop gains. This feature actually allows the EL2480 to maintain about the same -3dB bandwidth, regardless of closed-loop gain. However, as closed-loop gain is increased, bandwidth decreases slightly while stability increases. Since the loop stability is improving with higher closed-loop gains, it becomes possible to reduce the value of RF below the specified 560Ω and 750Ω and still retain stability, resulting in only a slight loss of bandwidth with increased closed-loop gain. Supply Voltage Range and Single-Supply Operation The EL2480 has been designed to operate with supply voltages having a span of greater than 3V, and less than 12V. In practical terms, this means that the EL2480 will operate on dual supplies ranging from ±1.5V to ±6V. With a single-supply, the EL2480 will operate from +3V to +12V. As supply voltages continue to decrease, it becomes necessary to provide input and output voltage ranges that can get as close as possible to the supply voltages. The EL2480 has an input voltage range that extends to within 1V of either supply. So, for example, on a single +5V supply, the EL2480 has an input range which spans from 1V to 4V. The output range of the EL2480 is also quite large, extending to within 1V of the supply rail. On a ±5V supply, the output is therefore capable of swinging from -4V to +4V. Single-supply output range is even larger because of the increased negative swing due to the external pull-down resistor to ground. On a single +5V supply, output voltage range is about 0.3V to 4V. EL2480 Video Performance For good video performance, an amplifier is required to maintain the same output impedance and the same frequency response as DC levels are changed at the output. This is especially difficult when driving a standard video load of 150Ω, because of the change in output current with DC level. Until the EL2480, good Differential Gain could only be achieved by running high idle currents through the output transistors (to reduce variations in output impedance). These currents were typically comparable to the entire 3mA supply current of EL2480 amplifier! Special circuitry has been incorporated in the EL2480 to reduce the variation of output impedance with current output. This results in dG and dP specifications of 0.05% and 0.05° while driving 150Ω at a gain of +2. modified for the EL2480 to remain in the safe operating area. These parameters are calculated as follows: T JMAX = T MAX + ( Θ JA × n × PD MAX ) where: TMAX = Maximum ambient temperature θJA = Thermal resistance of the package n = Number of amplifiers in the package PDMAX = Maximum power dissipation of each amplifier in the package PDMAX for each amplifier can be calculated as follows: V OUTMAX PD MAX = ( 2 × V S × I SMAX ) + ( V S - V OUTMAX ) × ---------------------------R L Video performance has also been measured with a 500Ω load at a gain of +1. Under these conditions, the EL2480 has dG and dP specifications of 0.01% and 0.01° respectively while driving 500Ω at AV = +1. where: VS = Supply voltage ISMAX = Maximum supply current of 1 amplifier Output Drive Capability This amplifier of the EL2480 is capable of providing a minimum of ±50mA. These output drive levels are unprecedented in amplifiers running at these supply currents. The ±50mA minimum output drive of the EL2480 amplifier allows swings of ±2.5V into 50Ω loads. Driving Cables and Capacitive Loads When used as a cable driver, double termination is always recommended for reflection-free performance. For those applications, the back-termination series resistor will decouple the EL2480 from the cable and allow extensive capacitive drive. However, other applications may have high capacitive loads without a back-termination resistor. In these applications, a small series resistor (usually between 5Ω and 50Ω) can be placed in series with the output to eliminate most peaking. The gain resistor (RG) can then be chosen to make up for any gain loss which may be created by this additional resistor at the output. In many cases it is also possible to simply increase the value of the feedback resistor (RF) to reduce the peaking. Current Limiting The EL2480 has no internal current-limiting circuitry. If any output is shorted, it is possible to exceed the Absolute Maximum Ratings for output current or power dissipation, potentially resulting in the destruction of the device. Power Dissipation With the high output drive capability of the EL2480, it is possible to exceed the 150°C Absolute Maximum junction temperature under certain very high load current conditions. Generally speaking, when RL falls below about 25Ω, it is important to calculate the maximum junction temperature (TJMAX) for the application to determine if power-supply voltages, load conditions, or package type need to be 10 VOUTMAX = Maximum output voltage of the application RL = Load resistance EL2480 Typical Application Circuits EL2480 EL2480 FAST-SETTLING PRECISION AMPLIFIER INVERTING 200mA OUTPUT CURRENT DISTRIBUTION AMPLIFIER 120 120 DIFFERENTIAL LINE-DRIVER/RECEIVER 11 EL2480 EL2480 Macromodel * EL2480 Macromodel * Revision A, March 1995 * AC characteristics used: Rf = Rg = 750Ω * Connections: +input * | -input * | | +Vsupply * | | | -Vsupply * | | | | output * | | | | | .subckt EL2480/el 3 2 4 11 1 * * Input Stage * e1 10 0 3 0 1.0 vis 10 9 0V h2 9 12 vxx 1.0 r1 2 11 400 l1 11 12 25nH iinp 3 0 1.5uA iinm 2 0 3uA r12 3 0 2Meg * * Slew Rate Limiting * h1 13 0 vis 600 r2 13 14 1K d1 14 0 dclamp d2 0 14 dclamp * * High Frequency Pole * e2 30 0 14 0 0.00166666666 l3 30 17 150nH c5 17 0 0.8pF r5 17 0 165 * * Transimpedance Stage * g1 0 18 17 0 1.0 rol 18 0 450K cdp 18 0 0.675pF * * Output Stage * q1 11 18 19 qp q2 4 18 20 qn q3 4 19 21 qn q4 11 20 22 qp r7 21 1 4 r8 22 1 4 ios1 4 19 1mA ios2 20 11 1mA * * Supply Current * ips 4 11 0.2mA * * Error Terms 12 EL2480 * ivos 0 23 0.2mA vxx 23 0 0V e4 24 0 3 0 1.0 e5 25 0 4 0 1.0 e6 26 0 11 0 -1.0 r9 24 23 316 r10 25 23 3.2K r11 26 23 3.2K * * Models * .model qn npn(is=5e-15 bf=200 tf=0.01nS) *.model qp pnp(is=5e-15 bf=200 tf=0.01nS) .model dclamp d(is=1e-30 ibv=0.266 + bv=0.71v n=4) .ends EL2480 Macromodel 4 1 11 All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 13