EL4093

FN7159 Rev 0.00

Page 7 of 12

January 1996

Applications Information

Product Description

The EL4093 is a high speed DC-restore system containing a

current feedback amplifier (CFA) and a sample & hold (S/H)

amplifier. The CFA offers a wide 3dB bandwidth of 300MHz

and a slew rate of 1500V/µs, making it ideal for high speed

video applications such as SVGA. The CFA’s excellent

differential gain and phase at 3.58MHz also makes it suitable

for NTSC applications. Drawing only 9.5mA on ±5V supplies,

the EL4093 serves as an excellent choice for those

applications requiring both low power and high bandwidth.

The connection between the CFA and sample & hold (the

Autozero interface) has been greatly simplified. The output of

the sample & hold is a high impedance current source,

allowing direct connection to the CFA inverting input for

autozero purposes. In addition, special circuitry within the

sample & hold provides a charge current of 8.5mA in sample

mode, resulting in a sample hold current ratio (ratio of charging

current to droop current) of approx. 1,000,000.

Theory of Operation

In video applications, DC restoration moves the backporch or

black level to a fixed DC reference. The EL4093 uses a CFA in

feedback with a sample & hold to provide DC restoration.

Differential Gain and

Phase vs DC Input

Voltage at 3.58MHz

Differential Gain and

Phase vs DC Input

Voltage at 3.58MHz

Slew Rate vs Die

Temperature (Video Amp)

Small-Signal Step Response

Large-Signal Step Response

Settling Time vs

Settling Accuracy

(Video Amp)

Maximum Power Dissipation

vs Ambient Temperature,

16-Pin PDIP Package

Maximum Power Dissipation

vs Ambient Temperature,

16-Pin SO Package