12

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

FN7058.4

September 14 ,2010

Single-Supply Operation

The EL2227s have been designed to have a wide input and

output voltage range. This design also makes the EL2227 an

excellent choice for single-supply operation. Using a single

positive supply, the lower input voltage range is within

range is within 875mV of ground. Upper input voltage range

reaches 3.6V, and output voltage range reaches 3.8V with a

swing on a single 5V supply. This wide output voltage range

also allows single-supply operation with a supply voltage as

high as 28V.

Gain-Bandwidth Product and the -3dB Bandwidth

The EL2227s have a gain-bandwidth product of 137MHz

while using only 5mA of supply current per amplifier. For

gains greater than 2, their closed-loop -3dB bandwidth is

approximately equal to the gain-bandwidth product divided

by the noise gain of the circuit. For gains less than 2, higher

order poles in the amplifiers' transfer function contribute to

even higher closed loop bandwidths. For example, the

EL2227 have a -3dB bandwidth of 115MHz at a gain of +2,

dropping to 28MHz at a gain of +5. It is important to note that

the EL2227 have been designed so that this “extra”

bandwidth in low-gain applications does not come at the

expense of stability. As seen in the typical performance

curves, the EL2227 in a gain of +2 only exhibit 0.5dB of

peaking with a 1000

Ω load.

Output Drive Capability

The EL2227s have been designed to drive low impedance

high output drive capability makes the EL2227 an ideal

choice for RF, IF and video applications.

Printed-Circuit Layout

The EL2227s are well behaved, and easy to apply in most

applications. However, a few simple techniques will help

assure rapid, high quality results. As with any high-frequency

device, good PCB layout is necessary for optimum

performance. Ground-plane construction is highly

recommended, as is good power supply bypassing. A 0.1µF

ceramic capacitor is recommended for bypassing both

supplies. Lead lengths should be as short as possible, and

bypass capacitors should be as close to the device pins as

possible. For good AC performance, parasitic capacitances

should be kept to a minimum at both inputs and at the

output. Resistor values should be kept under 5k

Ω because

of the RC time constants associated with the parasitic

capacitance. Metal-film and carbon resistors are both

acceptable, use of wire-wound resistors is not recommended

because of their parasitic inductance. Similarly, capacitors

should be low-inductance for best performance.

TABLE 1.

PART

PACKAGE

MAX PDISS @

EL2227CS

SO8

160°C/W 0.406W @ +85°C

EL2227CY

MSOP8

206°C/W 0.315W @ +85°C

EL2227