250MHz / 3mA Current Mode Feedback Amplifiers Features General Description • • • • • The EL2180C/EL2280C/EL2480C are single/dual/quad current-feedback operational amplifiers that achieve a -3dB bandwidth of 250MHz at a gain of +1 while consuming only 3mA of supply current per amplifier. They will operate with dual supplies ranging from ±1.5V to ±6V or from single supplies ranging from +3V to +12V. In spite of their low supply current, the EL2480C and the EL2280C can output 55mA while swinging to ±4V on ±5V supplies. The EL2180C can output 100mA with similar output swings. These attributes make the EL2180C/EL2280C/EL2480C excellent choices for low power and/or low voltage cable driver, HDSL, or RGB applications. Single, dual, and quad topologies 3mA supply current (per amplifier) 250MHz -3dB bandwidth 1200V/µs slew rate Tiny package package options (SOT23, LPP) • Low cost • Single- and dual-supply operation down to ±1.5V • 0.05%/0.05° diff. gain/diff. phase into 150Ω Applications • • • • • • • Low power/battery applications HDSL amplifiers Video amplifiers Cable drivers RGB amplifiers Test equipment amplifiers Current to voltage converters Ordering Information Package EL2180CN 8-Pin PDIP - MDP0031 EL2180CS 8-Pin SO - MDP0027 EL2180CS-T7 8-Pin SO 7” MDP0027 EL2180CS-T13 8-Pin SO 13” MDP0027 EL2180CW-T7 5-Pin SOT23 7” MDP0038 EL2180CW-T13 Part No For applications where board space is extremely critical, the EL2180C is available in the tiny 5-pin SOT23 package, with a footprint size 28% of an 8-pin SO. The EL2480C is also available in a 24-pin LPP package. All are specified for operation over the full -40°C to +85°C temperature range. Single, dual, and triple versions are also available with the enable function (EL2186C, EL2286C, and EL2386C). Connection Diagrams NC 1 Tape & Reel Outline # 13” MDP0038 8-Pin PDIP - MDP0031 EL2280CS 8-Pin SO - MDP0027 EL2280CS-T7 8-Pin SO 7” MDP0027 EL2280CS-T13 8-Pin SO 13” MDP0027 EL2480CN 14-Pin PDIP - MDP0031 EL2480CS 14-Pin SO - MDP0027 EL2480CS-T7 14-Pin SO 7” MDP0027 EL2480CS-T13 14-Pin SO 13” MDP0027 EL2480CL 24-Pin LPP - MDP0046 EL2480CL-T7 24-Pin LPP 7” MDP0046 EL2480CL-T13 24-Pin LPP 13” MDP0046 8 NC IN- 2 7 VS+ + IN+ 3 6 OUT VS- 4 5 NC EL2180C (8-Pin SO & 8-Pin PDIP) OUTA 1 INA- 2 8 VS+ A + 7 OUTB INA+ 3 VS- 4 6 INBB + 5 INB+ EL2280C (8-Pin SO & 8-Pin PDIP) Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation. © 2001 Elantec Semiconductor, Inc. July 19, 2001 5-Pin SOT23 EL2280CN EL2180C/EL2280C/EL2480C- EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers Absolute Maximum Ratings (T Supply Voltage between VS+ and GND Voltage between V S+ and VSCommon-Mode Input Voltage Differential Input Voltage Current into +IN or -IN Internal Power Dissipation Operating Ambient Temperature Range A = 25°C) +12.6V +12.6V VS- to VS+ ±6V ±7.5mA See Curves -40°C to +85°C Operating Junction Temperature Plastic Packages Output Current (EL2180C) Output Current (EL2280C) Output Current (EL2480C) Storage Temperature Range 150°C ±120mA ±60mA ±60mA -65°C to +150°C Important Note: All parameters having Min/Max specifications are guaranteed. Typ 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 Characteristics VS = ±5V, RL = 150Ω, TA = 25°C unless otherwise specified. Parameter Description Conditions Min Typ Max 2.5 10 Unit VOS Input Offset Voltage TCVOS Average Input Offset Voltage Drift Measured from TMIN to T MAX dVOS VOS Matching EL2280C, EL2480C only +IIN +Input Current d+IIN +IIN Matching -IIN -Input Current d-IIN -IIN Matching EL2280C, EL2480C only CMRR Common Mode Rejection Ratio VCM = ±3.5V -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 IO IS 5 0.5 1.5 EL2280C, EL2480C only Output Current Supply Current µA 40 µA nA 2 45 60 µA 50 5 VS = ±5 mV 15 20 16 dB 30 µA/V 15 µA/V 70 1 mV µV/°C dB EL2180C only 80 100 mA EL2280C only, per amplifier 50 55 mA EL2480C only, per amplifier 50 55 Per amplifier 3 mA 6 mA AC Electrical Characteristics VS = ±5V, RF = RG = 750Ω for PDIP and SO packages, RF = RG = 560Ω for SOT23-5 package, RL = 150Ω, TA = 25°C unless otherwise specified Parameter 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 = ±500 mV 1.5 ns 2 600 250MHz / 3mA Current Mode Feedback Amplifiers AC Electrical Characteristics VS = ±5V, RF = RG = 750Ω for PDIP and SO packages, RF = RG = 560Ω for SOT23-5 package, RL = 150Ω, TA = 25°C unless otherwise specified Parameter Description Conditions Min Typ Max Unit tPD Propagation Delay VOUT = ±500 mV 1.5 OS Overshoot VOUT = ±500 mV 3.0 % tS 0.1% Settling VOUT = ±2.5V, AV = -1 15 ns dG Differential Gain AV = +2, RL = 150Ω  0.05 % dP Differential Phase AV = +2, RL = 150Ω  0.05 ° dG Differential Gain AV = +1, RL = 500Ω  0.01 % dP Differential Phase AV = +1, RL = 500Ω  0.01 ° CS Channel Separation EL2280C, EL2480C only, f = 5 MHz 85 dB 1. DC offset from 0V to 0.714V, AC amplitude 286mVP-P, f = 3.58MHz Connection Diagrams (Continued) 4 IN- 20 IND- - 21 OUTD + IN+ 3 22 NC GND 2 23 OUTA 5 VS+ 24 INA- OUT 1 NC 1 EL2180C (5-Pin SOT23) 19 NC INA+ 2 18 IND+ NC 3 OUTA 1 17 NC 14 OUTD VS+ 4 INA- 2 - A + + D - Thermal Pad 16 VS- 13 INDNC 5 INA+ 3 12 IND+ VS+ 4 11 VS- INB+ 5 10 INC+ 15 NC INB+ 6 14 INC+ + C - OUTB 7 9 INC- EL2480C (24-Pin LPP - Top View) 8 OUTC EL2480C (14-Pin SO & 14-Pin PDIP) 3 INC- 12 + OUTC 11 B NC 10 - OUTB 9 INB- 6 13 NC INB- 8 NC 7 ns EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers Test Circuit (Per Amplifier) 0.1µF +5V VIN IN+ VS+ *see note IN- V S- OUT VOUT RL 0.1µF 150Ω -5V RG RF 750Ω 750Ω * Note: EL2180C or ½ EL2280C or ¼ EL2480C Simplified Schematic (Per Amplifier) V+ R2 V1 R3 Q2 Q3 R4 Q4 R5 Q5 Q9 Q7 Q6 Q8 I N+ OUT Q10 Q12 Q11 Q13 IN- Q14 R7 V2 V- 4 Q15 Q16 R8 R9 Q17 R10 250MHz / 3mA Current Mode Feedback Amplifiers Typical Performance Curves Non-Inverting Frequency Response (Gain) (PDIP and SOIC Packages) Non–Inverting Frequency Response (Phase) (PDIP and SOIC Packages) Inverting Frequency Response (Gain) (PDIP and SOIC Packages) Inverting Frequency Response (Phase) (PDIP and SOIC Packages) Transimpedance (ROL) vs Frequency PSRR and CMRR vs Frequency 5 Frequency Response for Various RF and RG (PDIP and SOIC Packages) Frequency Response for Various RL and C L (PDIP and SOIC Packages) Frequency Response for Various CIN- EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers Typical Performance Curves Voltage and Current Noise vs Frequency -3 dB Bandwidth and Peaking vs Supply Voltage for Various Non-Inverting Gains Supply Current vs Supply Voltage 2nd and 3rd Harmonic Distortion vs Frequency -3 dB Bandwidth and Peaking vs Supply Voltage for Various Inverting Gains Common-Mode Input Range vs Supply Voltage 6 Output Voltage Swing vs Frequency Output Voltage Swing vs Supply Voltage Slew Rate vs Supply Voltage 250MHz / 3mA Current Mode Feedback Amplifiers Typical Performance Curves Input Bias Current vs Die Temperature Short-Circuit Current vs Die Temperature Transimpedance (ROL) vs Die Temperature -3 dB Bandwidth and Peaking vs Die Temperature for Various Non-Inverting Gains -3 dB 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 EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers Typical Performance Curves Differential Gain and Phase vs DC Input Voltage at 3.58 MHz Differential Gain and Phase vs DC Input Voltage at 3.58 MHz Small-Signal Step Response 5-Lead Plastic SOT23 Maximum Power Dissipation vs Ambient Temperature Settling Time vs Settling Accuracy Large-Signal Step Response 8-Pin Plastic DIP Maximum Power Dissipation vs Ambient Temperature 8 8-Lead SO Maximum Power Dissipation vs Ambient Temperature 250MHz / 3mA Current Mode Feedback Amplifiers Typical Performance Curves 14-Pin Plastic DIP Maximum Power Dissipation vs Ambient Temperature Non-Inverting Frequency Response (Gain) (SOT23-5 Package) Inverting Frequency Response (Gain) (SOT23-5 Package) 14-Lead SO Maximum Power Dissipation vs Ambient Temperature Non-Inverting Frequency Response (Phase) (SOT23-5 Package) Inverting Frequency Response (Phase) (SOT23-5 Package) 9 Channel Separation vs Frequency Frequency Response for Various RF and RG (SOT23-5 Package) EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers Applications Information Product Description 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. The EL2180C/EL2280C/EL2480C are current-feedback operational amplifiers that offer a wide -3dB bandwidth of 250MHz and a low supply current of 3mA per amplifier. All of these products also feature high output current drive. The EL2180C can output 100mA, while the EL2280C and the EL2480C can output 55mA per amplifier. The EL2180C/EL2280C/EL2480C work with supply voltages ranging from a single 3V to ±6V and they are also capable of swinging to within 1V of either supply on the input and the output. Because of their current-feedback topology, the EL2180C/EL2280C/ EL2480C do not have the normal gain-bandwidth product associated with voltage-feedback operational amplifiers. This allows their -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 EL2180C/EL2280C/ EL2480C the ideal choice for many low-power/highbandwidth applications such as portable computing, HDSL, and video processing. 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, particularly for the SO package, 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 openloop response. The use of large value feedback and gain resistors further exacerbates the problem by further lowering the pole frequency. For applications where board space is extremely critical, the EL2180C is available in the tiny 5-pin SOT23 package, which has a footprint 28% the size of an 8-pin SO. The EL2480C is available in the 24-pin LPP package, offering board space savings and better power dissipation compared to the SO and PDIP packages. The EL2180C/EL2280C/EL2480C are each also available in industry-standard pinouts in PDIP and SO packages. For single, dual, and triple applications with disable, consider the EL2186C (8-pin single), EL2286C (14-pin dual), and EL2386C (16-pin triple). If lower power is required, refer to the EL2170C/EL2176C family which provides singles, duals, and quads with 70MHz of bandwidth while consuming 1mA of supply current per amplifier. The experienced user with a large amount of PC board layout experience may find in rare cases that the EL2180C/EL2280C/EL2480C have 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 R F and R G , and Frequency Response for Various CIN-. 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 10 250MHz / 3mA Current Mode Feedback Amplifiers Feedback Resistor Values example, on a single +5V supply, the EL2180C/ EL2280C/EL2480C have an input range which spans from 1V to 4V. The output range of the EL2180C/EL2280C/EL2480C 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. The EL2180C/EL2280C/EL2480C have been designed and specified at gains of +1 and +2 with RF = 750Ω in PDIP and SO packages and RF = 560Ω in 5-pin SOT23 package. 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. The 5-pin SOT23 package is characterized with a smaller value of feedback resistor, for a given bandwidth, to compensate for lower parasitics within both the package itself and the printed circuit board where it will be placed. Since the EL2180C/EL2280C/EL2480C are current-feedback amplifiers, it is also possible to change the value of R F 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. 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 EL2180C/EL2280C/EL2480C, 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 each EL2180C/EL2280C/EL2480C amplifier! Special circuitry has been incorporated in the EL2180C/EL2280C/EL2480C 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. Because the EL2180C/EL2280C/EL2480C are currentfeedback amplifiers, their gain-bandwidth product is not a constant for different closed-loop gains. This feature actually allows the EL2180C/EL2280C/EL2480C 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. Video Performance has also been measured with a 500Ω load at a gain of +1. Under these conditions, the EL2180C/EL2280C/EL2480C have dG and dP specifications of 0.01% and 0.01° respectively while driving 500Ω at AV = +1. Supply Voltage Range and Single-Supply Operation The EL2180C/EL2280C/EL2480C have 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 EL2180C/EL2280C/EL2480C will operate on dual supplies ranging from ±1.5V to ±6V. With a single-supply, the EL2180C/EL2280C/EL2480C will operate from +3V to +12V. Output Drive Capability In spite of its low 3mA of supply current, the EL2180C is capable of providing a minimum of ±80mA of output current. Similarly, each amplifier of the EL2280C and the EL2480C is capable of providing a minimum of ±50mA. These output drive levels are unprecedented in amplifiers running at these supply currents. With a minimum ±80mA of output drive, the EL2180C is capable of driving 50Ω loads to ±4V, making it an excellent choice for driving isolation transformers in telecommunications applications. Similarly, the ±50mA minimum 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 EL2180C/EL2280C/EL2480C have an input voltage range that extends to within 1V of either supply. So, for 11 EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers output drive of each EL2280C and EL2480C amplifier allows swings of ±2.5V into 50Ω loads. n = Number of Amplifiers in the Package PDMAX = Maximum Power Dissipation of Each Amplifier in the Package Driving Cables and Capacitive Loads PDMAX for each amplifier can be calculated as follows: 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 EL2180C/EL2280C/EL2480C 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. V OUTMAX PD MAX = ( 2 × V S × I SMAX ) + ( V S – V OUTMAX ) × ---------------------------RL where: VS = Supply Voltage ISMAX = Maximum Supply Current of 1 Amplifier VOUTMAX = Maximum Output Voltage of the Application RL = Load Resistance Current Limiting The EL2180C/EL2280C/EL2480C have 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 EL2180C/EL2280C/EL2480C, 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 powersupply voltages, load conditions, or package type need to be modified for the EL2180C/EL2280C/EL2480C 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 12 250MHz / 3mA Current Mode Feedback Amplifiers Typical Application Circuits 0.1µF +5V IN+ VS+ EL2180C OUT VSIN0.1µF -5V 750Ω 5Ω 0.1µF VOUT +5V IN+ VS+ EL2180C OUT VSIN- 5Ω 0.1µF -5V 750Ω 750Ω VIN Figure 1. Inverting 200mA Output Current Distribution Amplifier 750Ω 750Ω 0.1µF +5V IN+ *see note IN- VS+ V S- OUT 0.1µF 750Ω -5V 750Ω +5V 0.1µF VIN IN+ *see note IN- VS+ V S- OUT VOUT 0.1µF * Note: ½ EL2280C or ¼ EL2480C -5V Figure 2. Fast-Settling Precision Amplifier 13 EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers Typical Application Circuits (Continued) 0.1µF 0.1µF +5V +5V IN+ IN+ V S+ *see note OUT VSIN- V S+ *see note OUT VSIN- 0.1µF 0.1µF -5V -5V 750Ω 0.1µF 120Ω 750Ω 750Ω VOUT+ 1kΩ 0.1µF 240Ω +5V 0.1µF +5V IN+ V S+ *see note OUT VSIN- 0.1µF 120Ω VOUT- IN+ V S+ *see OUT *see note note VSIN- 1kΩ 0.1µF -5V 0.1µF 750Ω 750Ω -5V VIN 750Ω 750Ω TRANSMITTER * Note: EL2180 or ½ EL2280C or ¼ EL2480C RECEIVER Figure 3. Differential Line Driver/Receiver 14 VOUT 250MHz / 3mA Current Mode Feedback Amplifiers EL2180C/EL2280C/EL2480C Macromodel * EL2180 Macromodel * Revision A, March 1995 * AC characteristics used: Rf = Rg = 750 ohms * Connections: +input * | -input * | | +Vsupply * | | | -Vsupply * | | | | output * | | | | | .subckt EL2180/el 3 2 7 4 6 * * 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 4 18 19 qp q2 7 18 20 qn q3 7 19 21 qn q4 4 20 22 qp r7 21 6 4 r8 22 6 4 ios1 7 19 1mA ios2 20 4 1mA * * Supply Current * ips 7 4 0.2mA * * Error Terms * ivos 0 23 0.2mA vxx 23 0 0V e4 24 0 3 0 1.0 15 EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers e5 25 0 7 0 1.0 e6 26 0 4 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 16 EL2180C/EL2280C/EL2480C- EL2180C/EL2280C/EL2480C-Preliminary 250MHz / 3mA Current Mode Feedback Amplifiers General Disclaimer Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. WARNING - Life Support Policy Elantec, Inc. products are not authorized for and should not be used within Life Support Systems without the specific written consent of Elantec, Inc. Life Support systems are equipment intended to support or sustain life and whose failure to perform when properly used in accordance with instructions provided can be reasonably expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support Systems are requested to contact Elantec, Inc. factory headquarters to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective components and does not cover injury to persons or property or other consequential damages. July 19, 2001 Elantec Semiconductor, Inc. 675 Trade Zone Blvd. Milpitas, CA 95035 Telephone: (408) 945-1323 (888) ELANTEC Fax: (408) 945-9305 European Office: +44-118-977-6020 Japan Technical Center: +81-45-682-5820 17 Printed in U.S.A.