The EL8102 , EL8103 represent single rail-to-rail amplifiers with a bandwidth of 500MHz and a slew rate of -3dB at 600V/µs. Draining a very low 5.6mA supply current, the EL8102 and EL8103 also have an input, to 0.15V below the VS-rail. The EL8102 includes a quick-acting disable/power-down circuit. With 25ns disable and 200ns enable the EL8102 is ideal for multiplexing applications. The EL8102, EL8103 are designed for some general purpose video, communication, instrumentation, and industrial applications. The EL8102 is available in an 8 Ld SOIC package in a 6 Ld SOT-23 package and the EL8103 is available in a 5 Ld SOT-23 package. Everything works within the specified temperature range of -40°C to +85°C.

Schematic

Product Description

The EL8102, EL8103 are wide bandwidth, single supply, low supply and rail-to-rail output voltage feedback operational amplifiers. Both amplifiers use an internally compensated closed-loop gain of greater 1. When connected in voltage follower mode and driving a 1kΩ load, the EL8102 and EL8103 have a -3dB bandwidth of 500MHz. When driving a 150Ω load, the bandwidth is approximately 350MHz while maintaining a slew rate of 600V/µs. The EL8102 can have a power-down pin to reduce the power supply by 30µA typical while the amplifier is disabled.

Input, output and supply voltage ranges of the EL8102, EL8103 have been designed to operate with a single supply voltage of 3V to 5.0V. Split power supplies can also be used as long as their total voltage is between 3V and 5.0V. The amplifier's input common-mode voltage ranges from 0.15V below the negative supply (VS- pin) to within 1.5V of the positive supply (VS+ pin). If the input signal is outside the range specified above, the output signal will be distorted. The output of the EL8102, EL8103 can swing rail-to-rail. As the load resistance becomes lower, the drivability near each track is reduced. For a load resistance of 1kΩ, the output swings about 4.9V at a 5V supply. With a load resistance of 150Ω, the output swing is approximately 4.6V.

Ordering Information

Video performance

For good video performance, the amplifier needs to maintain the same output impedance and at the same frequency response as the DC level is changed at the output. This is especially difficult when finding a standard video load of 150Ω because of the variation in output current with the DC level. Special circuits have been incorporated in the EL8102, EL8103, to reduce the current output with the change in the output impedance. This results in DG and DP specs of 0.01% and 0.01° while driving at 150Ω 2. Driving a gain with high impedance loads will give similar or better dG and DP performance.

Driving capacitive loads and cables

The EL8102, EL8103 can drive a 10pF load in parallel with 1kΩ with less than 5dB peak gain of 1. If less peaking is desired in the application, a small series resistor (typically 5Ω to 50Ω) can be placed on the series output to eliminate most of the peaking. However, this reduces the gain slightly. If the gain is set to greater than 1, the gain resistor RG can then be chosen to compensate for any gain loss which can be created by adding a series resistor in the output. When used as a cable driver, dual termination is always recommended for non-reflective performance. For those applications, a reverse-terminated series resistor at the output of the amplifier will isolate the amplifier from the cable and allow for a wide range of capacitive drives. However, other applications can have high capacitive loads without back-terminating resistors. Also, a small resistor in series with the output can help to reduce peaking.