The EL5152 , EL5153 , EL5252 , EL5455 are 270MHz, -3dB bandwidth, voltage mode feedback amplifiers, <0.01% accuracy in DC, 1mV offset and 50kV/V open loop rise. These amplifiers are ideal for applications ranging from precision measuring instruments to high-speed video surveillance applications that require higher linearity at higher frequencies. Capable of operating with as little current as 3.0mA from a single supply ranging from 5V to 12V with dual voltage ranges of ±2.5V to ±5.0V these amplifiers are also ideal for handheld, portable and battery powered equipment. A single amplifier is offered in a SOT-23 package, even in a 10-pin MSOP package where board space is critical. The quad amplifiers are packaged in 14 Ld SOIC packages. Additionally, single and dual channels are available in industry standard 8 Ld SOIC packages. All components operate over an industrial temperature range of -40°C to +°C.

The EL5152, EL5153, EL5252, EL5455 and wide bandwidth, low power, low offset voltage feedback op amps are capable of single-OR operation with dual supplies. This series of op amps is internally compensated for closed loop gains of +1 or higher. Connected in voltage follower mode, driving a 500Ω load this amplifier family member exhibits a -3dB bandwidth around 270MHz. With the loading set to suit typical video applications, with a 150Ω load and a gain setting of 2, the bandwidth is reduced to about 180MHz with a 600V/µs slew rate. The EL5152 power down pin and the EL5252 reduce this already low power demand amplifier series, to 17µA typical, while the amplifier is disabled.

Input, output and supply voltage ranges

The EL5152 and EL5153 series have been designed to operate with a supply voltage range of 5V to 12V. Discrete power supply with supply voltage range of ±2.5V to ±5V. Of course split power supply operation can be easily achieved using a single power supply, by splitting the single power supply in half and applying a simple voltage divider circuit part as shown.

Input common mode range

The input common mode voltage of these amplifiers ranges from 1.5V above the negative supply (VS- pin) to 1.5V below the positive supply (VS+ pin). If the input signal is driven outside this range, the output signal will show distortion.

Maximum Output Swing & Load Resistor The maximum output of the EL5152 and EL5153 families ranges from -4V to a 4V output swing of VS=±5V with a load of 500Ω resistor. Of course, as the load resistance gets lower, the output swing decreases accordingly; for example, if the load resistance is 150Ω, the output swing will range from -3.5V to 3.5V. This response is a simple application of Ohm's law showing that lower resistance values result in greater current demands on the amplifier. In addition, the load resistance affects the frequency response of this family, as well as all op amps, as clearly indicated by the gain versus frequency curves of various RLs. In the case of frequency to reduce the load response to reduce the bandwidth resistance is a conjunct function of the load resistance of the amplifier's output zero response.

The feedback resistor must achieve unity gain; simply connect the short output pin to the inverting input terminal. A gain larger than 1 requires the feedback and gain resistors to set the desired gain. This gets interesting because the feedback resistor forms a pole inverting the input with the parasitic capacitance. As the feedback resistance increases where the magnetic pole shifts in the frequency domain, the phase margin of the amplifier decreases and the amplifier becomes less stable. This transition is symptomatic with peaks in the frequency domain and still in the time domain at the extreme positions. Therefore, we want to keep the feedback resistor as small as possible. You may need to use a large number of feedback resistors for some reason; in this case a parallel feedback resistor in the range of a few picofarads is recommended to compensate for pole shifting and maintain a stable small capacitance. For gains greater than unity, feedback resistors from 500Ω to 750Ω have been determined to provide the best response.

Video performance

For good video performance, the amplifier needs to maintain the same output impedance and the same frequency response as the DC level is changed at the output; this characteristic is widely known as "diffgain - diffphase". Many amplifiers have trouble driving standard video loads of 150Ω with this particular one, as the output current has a natural tendency to vary with the DC level. The EL5152DG and DP for these families are a respectable 0.006% and 0.04%, while driving high impedance loads with a gain of 2 when driving 150Ω also yields similar or better dG and dp performance as placed at the current output Demand amplifiers are reduced with increased loads.