EL2480CSZ-T13 - Intersil Corporation

FN7055.1

EL2480

250MHz/3mA Current Mode Feedback

Amplifier

The EL2480 is a quad current-feedbac k operational amplifier

which achiev es a -3dB bandwidth of 250MHz at a gain of +1

while consuming only 3mA of supply current per amplifier. It

will operate with dual supplies ranging from ±1.5V to ±6V, or

from single supplies ranging from +3V to +12V. In spite of its

low supply current, the EL2480 can output 55mA while

s winging to ±4V on ±5V supplies. These attributes make the

EL2480 an e xcellent choice for lo w pow er and/or low v oltage

cable-driver, HDSL, or RGB applications.

F or triple applications with disable, consider the EL2386 (16-

pin triple).

Features

• Quad topology

• 3mA supply current (per amplifier)

• 250MHz -3dB bandwidth

• Low cost

• Single- and dual-supply operation down to ±1.5V

• 0.05%/0.05° diff. gain/diff. phase into 150Ω

• 1200V/µs slew rate

• Large output drive current - 55mA

• Also available with disable in triple

•Pb-Free plus Anneal available (RoHS compliant)

Applications

• Low power/battery applica tio ns

• HDSL amplifiers

• Video amplifiers

• Cable drivers

• RGB amplifiers

• Test equipment amplifiers

• Current to voltage converters

Pinout EL2480

(14-PIN SO)

TOP VI EW

Ordering Information

PART NUMBER PACKAGE TAPE & REEL PKG.

DWG. #

EL2480CS 14-Pin SO - MDP0027

EL2480CS-T7 14-Pin SO 7” MDP0027

EL2480CS-T13 14-Pin SO 13” MDP0027

EL2480CSZ

(See Note) 14-Pin SO

(Pb-free) - MDP0027

EL2480CSZ-T7

(See Note) 14-Pin SO

(Pb-free) 7” MDP0027

EL2480CSZ-T13

(See Note) 14-Pin SO

(Pb-free) 13” MDP0027

NOTE: Intersil Pb-free products employ special Pb-free material sets;

molding compounds/die attach materials and 100% matte tin plate

termination finish, which are RoHS compliant and compatible with

both SnPb and Pb-free soldering operations. Intersil Pb-free products

are MSL classified at Pb-free peak reflow temperatures that meet or

exceed the Pb-free requirements of IPC/JEDEC J STD-020.

Data Sheet May 23, 2005

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-352-6832 |Intersil (and design) is a registered trademark of Intersil Americas Inc.

All other trademarks mentioned are the property of their respective owners.

Absolute Maximum Ratings (TA = 25°C)

Supply Voltage between VS+ and GND. . . . . . . . . . . . . . . . . +12.6V

Voltage between VS+ and VS-. . . . . . . . . . . . . . . . . . . . . . . . +12.6V

Common-Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . VS- to VS+

Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±6V

Current into +IN or -IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±7.5mA

Internal Power Dissipation. . . . . . . . . . . . . . . . . . . . . . . See Curves

Operating Ambient Temperature Range . . . . . . . . . .-40°C to +85°C

Operating Junction Temperature

Plastic Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C

Output Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±60mA

Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the

device at these or any other conditi ons above those indicated in the operational sections of this specification is not implied.

IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical 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 Specificat ions VS = ±5V, RL = 150Ω, TA = 25°C unless otherwise specified

PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT

VOS Input Offset Voltage 2.5 10 mV

TCVOS Average Input Offset Voltage Drift Measured from TMIN to TMAX 5µV/°C

dVOS VOS Matching 0.5 mV

+IIN +Input Current 1.5 15 µA

d+IIN +IIN Matching 20 nA

-IIN -Input Current 16 40 µA

d-IIN -IIN Matching 2µA

CMRR Common Mode Rejection Ratio VCM = ±3.5V 45 50 dB

-ICMR -Input Current Common Mode

Rejection VCM = ±3.5V 5 30 µA/V

PSRR Power Supply Rejection Ratio VS is moved from ±4V to ±6V 60 70 dB

-IPSR - Input Current Power Supply

Rejection VS is moved from ±4V to ±6V 1 15 µA/V

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

VOOutput Voltage Swing VS = ±5 ±3.5 ±4.0 V

VS = 5 single-supply, high 4.0 V

VS = 5 single-supply, low 0.3 V

IOOutput Current Per amplifier 50 55 mA

ISSupply Current Per amplifier 3 6 mA

EL2480

AC Electrical Specifications VS=±5V, R

F=R

G= 750Ω, 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 = 2 600 1200 V/µs

tR, tFRise and Fall Time VOUT = ±500mV 1.5 ns

tPD Propagation Delay VOUT = ±500mV 1.5 ns

OS Overshoot VOUT = ±500mV 3.0 %

tS0.1% Settling VOUT = ±2.5V, AV = -1 15 ns

dG Differential Gain AV = 2, RL = 150Ω (Note 1) 0.05 %

dP Differential Phase AV = 2, RL = 150Ω (Note 1) 0.05 °

dG Differential Gain AV = 1, RL = 500Ω (Note 1) 0.01 %

dP Differential Phase AV = 1, RL = 500Ω (Note 1) 0.01 °

CSChannel Separation f = 5MHz 85 dB

NOTE:

1. DC offset from 0V to 0.714V, AC amplitude 286mVP-P, f = 3.58MHz

EL2480

Test Circuit (per Amplifier)

Simplified Schematic (per Amplifier)

EL2480

Typical Performance Curves

Non-Inverting Frequency

Response (Gain) Non–Inverting Frequency

Response (Phase) Frequency Response

for Various RF and RG

Inverting Frequency

Response (Gain) Inverting Frequency

Response (Phase) Frequency Response

for Various RL and CL

Frequency Response for

Various CIN-

PSRR and CMRR

vs Frequency

Transimpedance (ROL) vs

Frequency

Ω

EL2480

Typical Performance Curves (Continued)

Voltage and Current

Noise vs Frequency 2nd and 3rd Harmonic

Distortion vs Frequency Output Voltage

Swing vs Frequency

Output Voltage Swing

vs Supply Voltage

-3dB Bandwidth and Peaking

vs Supply Voltage for

Various Inverting Gains

-3dB Bandwidth and Peaking

vs Supply Voltage for

Various Non-Inverting Gains

Supply Current vs Supply Voltage Common-Mode Input Range

vs Supply Voltage Slew Rate vs Supply Voltage

EL2480

Typical Performance Curves (Continued)

Input Bias Current

vs Die Temperature Short-Circuit Current

vs Die Temperature Transimpedance (ROL)

vs Die Temperature

-3dB Bandwidth and Peaking

vs Die Temperature for

Various Non-Inverting Gains

-3dB Bandwidth vs

Die Temperature for

Various Inverting Gains Input Offset Voltage

vs Die Temperature

Slew Rate vs Die Temperature

Input Voltage Range

vs Die Temperature

Supply Current vs Die Temperature

EL2480

Typical Performance Curves (Continued)

Differential Gain and

Phase vs DC Input

Voltage at 3.58MHz

Differential Gain and

Phase vs DC Input

Voltage at 3.58MHz Settling Time vs

Settling Accuracy

Small-Signal Step Response Large-Signal Step Response

Channel Separation

vs Frequency

1.420W

θJA=88°C/W

SO14

1.8

1.6

1.4

0.8

0.6

0.2

0 25 50 75 100 150

AMBIENT TEMPERATURE (°C)

POWER DISSIPATION (W)

12585

JEDEC JESD51-7 HIGH EFFECTIVE

THERMAL CONDUCTIVITY TEST BOARD

0.4

1.2

1.042W

θJA=120°C/W

SO14

1.2

0.8

0.6

0.2

0 25 50 75 100 150

AMBIENT TEMPERATURE (°C)

POWER DISSIPATION (W)

12585

JEDEC JESD51-3 LOW EFFECTIVE

THERMAL CONDUCTIVITY TEST BOARD

0.4

EL2480

Applications Information

Product Description

The EL2480 is a current-feedback operational amplifier that

offers a wide -3dB bandwidth of 250MHz and a low supply

current of 3mA per amplifier. This product also features high

output current drive. The EL2480 can output 55mA per

amplifier. The EL2480 works with supply voltages ranging

from a single 3V to ±6V, and it is also capable of swinging to

within 1V of either supply on the input and the output.

Because of its current-feedback topology, the EL2480 does

not hav e the normal gain-bandwidth product associated with

voltage-feedback operational amplifiers. This allows its -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 EL2480

the ideal choice for many low-power/high-bandwidth

applications such as portable computing, HDSL, and video

processing.

The EL2480 is available in the industry standard SO

package. For triple application with disable, consider the

EL2386 (16-pin tr iple).

Power Supply Bypassing and Printed Circuit

Board Layout

As with any high-frequency device, good printed circuit

board lay out is necessary for optimum perf ormance. Ground

plane construction is highly recommended. Lead lengths

should be as short as possible. The power 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 suppl y pin.

For good AC performance, parasitic capacitance should be

kept to a minimum especially at the inverting input (see the

Capacitance at the Inverting Input secti on). 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 seri es

inductance. Use of sockets, should be avoided if possible.

Sock ets add parasitic inductance and capacitance which will

result in some additional peaking and overshoot.

Capacitance at the Inverting Input

Any man ufacturer'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 open-loop response. The use of large

value feedback and gain resistors further exacerbates the

problem by further lowering the pole frequency.

The experienced user with a large amount of PC board

layout experience may find in rare cases that the EL2480

has less bandwidth than expected.

The reduction of feedback resistor values (or the addition of

a very small amount of external capacitance at the inv erting

input, e.g. 0.5pF) will increase bandwidth as desired. Please

see the curves for Frequency Response for Various RF and

RG, and F r equency Response for Various CIN-.

Feedback Resistor Values

The EL2480 has been designed and specified at gains of +1

and +2 with RF = 750Ω. These values of feedback resistors

give 250MHz of -3dB bandwidth at A V= +1 with about 2.5dB

of peaking, and 180MHz of -3dB bandwidth at AV = +2 with

about 0.1dB of peaking. Since the EL2480 is current-

feedback amplifier, it is also possible to change the value of

RF 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.

Because the EL2480 is current-feedback amplifier, its gain-

bandwidth product is not a constant f or different closed-loop

gains. This feature actually allows the EL2480 to maintain

about the same -3dB bandwidth, regardless of closed-loop

gain. However, as closed-loo p 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.

Supply Voltage Range and Single-Supply

Operation

The EL2480 has been designed to ope rate with supply

voltages having a span of greater than 3V, and less than

12V. In practical term s, this means that the EL24 80 will

operate on dual supplies ranging from ±1.5V to ±6V. With a

single-supply, the EL2480 will operate from +3V to +12V.

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

EL2480 has an input voltage range that extends to within 1V

of either supply. So, for e xample, on a single +5V supply, the

EL2480 has an input range which spans fro m 1V to 4V. The

output range of the EL2480 is also qui te large, extending to

within 1V of the supply rail. On a ±5V supply, the output is

therefore capab le of s winging from -4V to +4V. Single-supply

output range is even larger because of the increased

negative swing due to the exter nal pull-down resistor to

ground. On a single +5V supply, output voltage range is

about 0.3V to 4V.

EL2480

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 EL2480, good Differential Gain could only be

achieved by runni ng 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 EL2480 amplifier! Special circuitry has been

incorporated in the EL2480 to reduce the variation of output

impedance with current output. This results in dG and dP

specifications of 0.05% and 0.05° while dr iving 150Ω at a

gain of +2.

Video performance has also been measured with a 500Ω

load at a gain of +1. Under these conditions, the EL2480 has

dG and dP specifications of 0.01% and 0.01° respectively

while drivin g 500Ω at AV = +1.

Output Drive Capability

This amplifier of the EL2480 is capable of pro viding a

minimum of ±50mA. These output drive lev els are

unprecedented in a mplifiers running at these supply currents.

The ±50mA minimum output driv e of the EL2480 amplifie r

allows swings of ±2.5V into 50Ω loads.

Driving Cables and Capacitive Loads

When used as a cab le driv er, double termination is alw ays

recommended for reflection-free performance. For those

applications , the back-termination series resistor will decouple

the EL2480 from the cab le and al lo w extensive capacitive

drive . Ho wev er, other applications ma y hav e hig h cap acitive

loads without a bac k -termination resistor. In these

applications , a small series resistor (usually between 5 Ω and

50Ω) can be placed in series with the output to eliminate most

peaking. The gain resi stor (R G) can then be chosen to mak e

up f or an y gain loss which may be created by this additional

resistor at the output. In many cases it is also possible to

simply increase the v alu e of the feedback resistor (RF) to

reduce the peaking.

Current Limiting

The EL2480 has no internal current-limiting circuitry. If any

output is shorted, it is possible to e xceed the Absolute

Maximum Ratings for output current or power dissipation,

potentially resulting in the destruction of the de vice .

Po wer Dissipation

With the high output driv e capability of the EL2 480, it is

possib le to exceed the 150°C Absolute Maximum juncti on

temperature under ce rtain very high load current conditions.

Generally speaking , when RL f alls be lo w about 25 Ω, it is

important to calculate the maximum j unction temper a ture

(TJMAX) for the application to determine if pow er-supply

v oltages , lo ad co nditions, or pac kage type nee d to be

modified f or the EL2480 to remain in the safe operating area.

These parameters are calcu lated as follo ws:

where:

TMAX = Maximum ambient temperature

θJA = Thermal resistance of the pac kag e

n = Number of amplifiers in the pack age

PDMAX = Maximum po w er d issipation of each ampli fier in

the packa ge

PDMAX f or each amplifier can be calculated as follows:

where:

VS = Supply v oltag e

ISMAX = Maxi mum sup ply current of 1 amplifier

VOUTMAX = Maximum output voltage of the a pplication

RL = Load resistance

TJMAX TMAX ΘJA nPD

MAX

××()+=

PDMAX 2(VSISMAX)VS

( - VOUTMAX)VOUTMAX

----------------------------

×+××=

EL2480

Typical Application Circuits

INVERTING 200mA OUTPUT CURRENT DISTRIBUTION

AMPLIFIER

FAST-SETTLING PRECISION AMPLIFIER

EL2480

DIFFERENTIAL LINE-DRIVER/RECEIVER

120

EL2480

EL2480 Macromodel

* EL2480 Macromodel

* Revision A, March 1995

* AC characteristics used: Rf = Rg = 750Ω

* Connections: +input

* | -input

* | | +Vsupply

* | | | -Vsupply

* | | | | output

* | | | | |

.subckt EL2480/el 3 2 4 11 1

* 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 11 18 19 qp

q2 4 18 20 qn

q3 4 19 21 qn

q4 11 20 22 qp

r7 21 1 4

r8 22 1 4

ios1 4 19 1mA

ios2 20 11 1mA

* Supply Current

ips 4 11 0.2mA

* Error Terms

EL2480

All Intersil U.S. products are man ufactured, 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 i s gr a nted b y imp lica tion or oth erw ise unde r any patent or pat ent rights of In tersi l or its sub sidi aries.

For information regarding Intersil Corporation and its products, see www.intersil.com

ivos 0 23 0.2mA

vxx 23 0 0V

e4 24 0 3 0 1.0

e5 25 0 4 0 1.0

e6 26 0 11 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

EL2480 Macromodel

EL2480