EVALUATION KIT

19-1230; Rev 2a; 6/97


AVAILABLE

1GHz, Low-Pow er, SOT23, Current-Feedback Amplifiers with Shutdown

MAX4223–MAX4228

General Description Features

The MAX4223–MAX4228 current-feedback amplifiers combine ultra-high-speed performance, low distortion, and excellent video specifications with low-power oper- ation. The MAX4223/MAX4224/MAX4226/MAX4228

have a shutdown feature that reduces power-supply current to 350µA and places the outputs into a high- impedance state. These devices operate with dual sup- plies ranging from ± 2.85V to ± 5.5V and provide a typical output drive current of 80mA. The MAX4223/ MAX4225/MAX4226 are optimized for a closed-loop gain of +1 (0dB) or more and have a -3dB bandwidth of 1GHz, while the MAX4224/MAX4227/MAX4228 are compensated for a closed-loop gain of +2 (6dB) or more, and have a -3dB bandwidth of 600MHz (1.2GHz gain-bandwidth product).

The MAX4223–MAX4228 are ideal for professional video applications, with differential gain and phase errors of 0.01% and 0.02°, 0.1dB gain flatness of 300MHz, and a 1100V/µs slew rate. Total harmonic distortion (THD) of

-60dBc (10MHz) and an 8ns settling time to 0.1% suit these devices for driving high-speed analog-to-digital inputs or for data-communications applications. The low- power shutdown mode on the MAX4223/MAX4224/ MAX4226/MAX4228 makes them suitable for portable and battery-powered applications. Their high output impedance in shutdown mode is excellent for multiplex- ing applications.

The single MAX4223/MAX4224 are available in space- Ordering Information


PART


TEMP. RANGE

PIN- PACKAGE

SOT TOP MARK

MAX4223EUT-T

-40°C to

+85°C

6 SOT23

AAAD

MAX4223ESA

-40°C to

+85°C

8 SO

saving 6-pin SOT23 packages. All devices are available

in the extended -40°C to +85°C temperature range.

Applications

ADC Input Buffers Data Communications

Video Cameras Video Line Drivers

Video Switches Video Multiplexing

Video Editors XDSL Drivers


Ordering Information continued at end of data sheet.

RF Receivers Differential Line Drivers Selector Guide


PART

MIN. GAIN

AMPS PER PKG.

SHUT- DOWN MODE

PIN- PACKAGE

MAX4223

1

1

Yes

6 SOT23, 8 SO

MAX4224

2

1

Yes

6 SOT23, 8 SO

MAX4225

1

2

No

8 SO

MAX4226

1

2

Yes

10 µMAX,

14 SO

MAX4227

2

2

No

8 SO

MAX4228

2

2

Yes

10 µMAX,

14 SO

Pin Configurations


TOPVIEW

OUT 1 6 VCC


VEE 2 5 SHDN


IN+ 3 4 IN-

Pin Configurations MAX4223

continued at end MAX4224

of data sheet. SOT23-6

Maxim Integrated Products 1


For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 For small orders, phone 408-737-7600 ext. 3468.


MAX4223–MAX4228

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (VCC to VEE) ..................................................12V Analog Input Voltage .......................(VEE - 0.3V) to (VCC + 0.3V) Analog Input Current ........................................................±25mA SHDN Input Voltage.........................(VEE - 0.3V) to (VCC + 0.3V)

Short-Circuit Duration

OUT to GND ...........................................................Continuous

OUT to VCC or VEE............................................................5sec


Continuous Power Dissipation (TA = +70°C)

6-Pin SOT23 (derate 7.1mW/°C above +70°C).............571mW

8-Pin SO (derate 5.9mW/°C above +70°C)...................471mW

10-Pin µMAX (derate 5.6mW/°C above +70°C) ............444mW

14-Pin SO (derate 8.3mW/°C above +70°C).................667mW

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

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

Lead Temperature (soldering, 10sec) .............................+300°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

DC ELECTRICAL CHARACTERISTICS

(VCC = +5V, VEE = -5V, SHDN = 5V, VCM = 0V, RL = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS


Input Offset Voltage


VOS

TA = +25°C

MAX4223/MAX4224


±0.5

±4


mV

MAX4225–MAX4228


±0.5

±5

TA = TMIN to TMAX

MAX4223/MAX4224

±6

MAX4225–MAX4228

±7

Input Offset Voltage Drift

TCVOS


±2

µV/°C

Input Bias Current (Positive Input)

IB+

TA = +25°C


±2

±10

µA

TA = TMIN to TMAX

±15


Input Bias Current (Negative Input)


IB-

TA = +25°C

MAX4223/MAX4224


±4

±20


µA

MAX4225–MAX4228


±4

±25

TA = TMIN to TMAX

MAX4223/MAX4224

±30

MAX4225–MAX4228

±35

Input Resistance (Positive Input)

RIN+


700

k

Input Resistance (Negative Input)

RIN-


45

Input Common-Mode Voltage Range

VCM

Inferred from CMRR test

±2.5

±3.2


V

Common-Mode Rejection Ratio

CMRR

VCM = ±2.5V

TA = +25°C

55

61


dB

TA = TMIN to TMAX

50

Operating Supply Voltage Range

VCC/VEE

Inferred from PSRR test

±2.85


±5.5

V

Power-Supply Rejection Ratio

PSRR

VCC = 2.85V to 5.5V, VEE = -2.85V to -5.5V

TA = +25°C

68

74


dB

TA = TMIN to TMAX

63

Quiescent Supply Current (per Amplifier)

ISY

Normal mode (SHDN = 5V)


6.0

9.0

mA

Shutdown mode (SHDN = 0V)


0.35

0.55

Open-Loop Transresistance

TR

VOUT = ±2.5V

RL =

0.7

1.5


M

RL = 50

0.3

0.8


Output Voltage Swing

VOUT

RL = 50

±2.5

±2.8


V

Output Current (Note 2)

IOUT

VOUT = ±2.5V

60

80


mA

Short-Circuit Output Current

ISC

RL = short to ground

140

mA

SHDN Logic Low

VIL


0.8

V

SHDN Logic High

VIH


2.0

V


MAX4223–MAX4228

DC ELECTRICAL CHARACTERISTICS (continued)

(VCC = +5V, VEE = -5V, SHDN = 5V, VCM = 0V, RL = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN TYP MAX

UNITS

SHDN Input Current

IIL/IIH

SHDN = 0V or 5V

25 70

µA

Shutdown Mode Output Impedance


SHDN = 0V, VOUT = -2.5V to +2.5V

(Note 3)

10 100

k


AC ELECTRICAL CHARACTERISTICS

(VCC = +5V, VEE = -5V, SHDN = 5V, VCM = 0V, AV = +1V/V for MAX4223/MAX4225/MAX4226, AV = +2V/V for MAX4224/MAX4227/

MAX4228, RL = 100, TA = +25°C, unless otherwise noted.) (Note 4)


PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

-3dB Small-Signal Bandwidth (Note 5)

BW

VOUT = 20mVp-p

MAX4223/5/6

750

1000

MHz

MAX4224/7/8

325

600

Bandwidth for ±0.1dB Gain Flatness (Note 5)

BW0.1dB

VOUT = 20mVp-p

MAX4223/5/6

100

300

MHz

MAX4224/7/8

60

200

Gain Peaking


MAX4223/5/6

1.5

dB

MAX4224/7/8

0.1

Large-Signal Bandwidth

BWLS

VOUT = 2Vp-p

MAX4223/5/6

250

MHz

MAX4224/7/8

330


Slew Rate (Note 5)


SR


VOUT = 4V step

Rising edge

MAX4223/5/6

850

1100


V/µs

MAX4224/7/8

1400

1700

Falling edge

MAX4223/5/6

625

800

MAX4224/7/8

1100

1400

Settling Time to 0.1%

tS

VOUT = 2V step

MAX4223/5/6

8

ns

MAX4224/7/8

5

Rise and Fall Time

tr, tf

VOUT = 2V step

MAX4223/5/6

1.5

ns

MAX4224/7/8

1.0

Off Isolation


SHDN = 0V, f = 10MHz, MAX4223/4/6/8

65

dB

Crosstalk

XTALK

f = 30MHz, RS = 50

MAX4225/6

-68

dB

MAX4227/8

-72

Turn-On Time from Shutdown

tON

MAX4223/4/6/8

2

µs

Turn-Off Time to Shutdown

tOFF

MAX4223/4/6/8

300

ns

Power-Up Time

tUP

VCC, VEE = 0V to ±5V step

100

ns

Differential Gain Error

DG

RL = 150 (Note 6)

MAX4223/5/6

0.01

%

MAX4224/7/8

0.02

Differential Phase Error

DP

RL = 150 (Note 6)

MAX4223/5/6

0.02

degrees

MAX4224/7/8

0.01


Total Harmonic Distortion


THD


VOUT = 2Vp-p, fC = 10MHz

RL = 100

MAX4223/5/6

-60


dBc

MAX4224/7/8

-61

RL = 1k

MAX4223/5/6

-65

MAX4224/7/8

-78


MAX4223–MAX4228

AC ELECTRICAL CHARACTERISTICS (continued)

(VCC = +5V, VEE = -5V, SHDN = 5V, VCM = 0V, AV = +1V/V for MAX4223/MAX4225/MAX4226, AV = +2V/V for MAX4224/MAX4227/

MAX4228, RL = 100, TA = +25°C, unless otherwise noted.) (Note 4)

PARAMETER

SYMBOL

CONDITIONS

MIN TYP MAX

UNITS

Output Impedance

ZOUT

f = 10kHz

2

Third-Order Intercept

IP3

f = 30kHz

fz = 30.1MHz

MAX4223/5/6

42

dBm

MAX4224/7/8

36

Spurious-Free Dynamic Range

SFDR

f = 10kHz

MAX4223/5/6

-61

dB

MAX4224/7/8

-62

1dB Gain Compression


f = 10kHz

20

dBm

Input Noise Voltage Density

en

f = 10kHz

2

nV/Hz

Input Noise Current Density

in+, in-

f = 10kHz

IN+

3

pA/Hz

IN-

20


Input Capacitance (Note 7)


CIN

SO-8, SO-14

packages

Pin to pin

0.3


pF

Pin to GND

1.0

SOT23-6, 10-pin µMAX

packages

Pin to pin

0.3

Pin to GND

0.8


Note 1: The MAX422_EUT is 100% production tested at TA = +25°C. Specifications over temperature limits are guaranteed by design.

Note 2: Absolute Maximum Power Dissipation must be observed.

Note 3: Does not include impedance of external feedback resistor network.

Note 4: AC specifications shown are with optimal values of RF and RG. These values vary for product and package type, and are tabulated in the Applications Information section of this data sheet.

Note 5: The AC specifications shown are not measured in a production test environment. The minimum AC specifications given are based on the combination of worst-case design simulations along with a sample characterization of units. These minimum specifications are for design guidance only and are not intended to guarantee AC performance (see AC Testing/ Performance). For 100% testing of these parameters, contact the factory.

Note 6: Input Test Signal: 3.58MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0IRE to 100IRE). IRE is a unit of video signal amplitude developed by the International Radio Engineers. 140IRE = 1V.

Note 7: Assumes printed circuit board layout similar to that of Maxim’s evaluation kit.

Typical Operating Characteristics

(VCC = +5V, VEE = -5V, RL = 100, TA = +25°C, unless otherwise noted.)


MAX4223

SMALL-SIGNALGAIN vs. FREQUENCY (AVCL= +1)

MAX4223-01

VIN=20mVp-p
















S

O-

8PAC

K

AG

E









R

F=

560









































SOT2

3-

6












RF=

47

0














































4

3

2

1

GAIN(dB)

0

-1

-2

-3

-4

-5

-6

MAX4223

SMALL-SIGNALGAIN vs. FREQUENCY (AVCL= +2/+5)

VIN=20mVp-p

MAX4223-02

4

3


00

/V

=2

2V

G

AV=+

RF=R

NORMALIZEDGAIN(dB)

2

1

0

-1

V/V

0

+5

10

-2 AV=

25

G=

R

-3 RF=

-4

-5

-6

MAX4223/MAX4225/MAX4226 LARGE-SIGNALGAIN vs. FREQUENCY

(AVCL= +1)

MAX4223-03

4

3 AV=+1V/V RF=560

2 VOUT=2Vp-p

1

GAIN(dB)

0

-1

-2

-3

-4

-5

-6

1 10

100 1000

1 10

100 1000

1 10

100 1000


MAX4223–MAX4228

Typical Operating Characteristics (continued)

(VCC = +5V, VEE = -5V, RL = 100, TA = +25°C, unless otherwise noted.)

MAX4224

SMALL-SIGNALGAIN vs. FREQUENCY (AVCL= +2)

VIN=20mVp-p

MAX4223-04

4

3

NORMALIZEDGAIN(dB)

2

1

0

-1


E


G


ACKA


O-


S

-2

=470

8P

RG

F=

R

-3

GE

CKA

PA

3-6

T2

SO

-4

0

47

G=

=R

RF

-5

-6

MAX4224

SMALL-SIGNALGAIN vs. FREQUENCY (AVCL= +5/+10)

Vp-p

0m

=2

N

VI

MAX4223-05

4

/V

+5V

L=


VC

A

3

0

NORMALIZEDGAIN(dB)

2 RF=24

1 RG=62

0

-1

-2 AVCL=+10V/V RF=130

-3 RG=15

-4

-5

-6

MAX4224/MAX4227/MAX4228 LARGE-SIGNALGAIN vs. FREQUENCY

(AVCL= +2)

MAX4223-06

4

AVCL=+2V/V

3 RF=RG=470

NORMALIZEDGAIN(dB)

2 VOUT=2Vp-p 1

0

-1

-2

-3

-4

-5

-6

1 10

100 1000

1 10

100 1000

1 10

100 1000

FREQUENCY(MHz)


MAX4225/MAX4226

SMALL-SIGNALGAIN vs. FREQUENCY (AVCL= +1)

MAX4223-07

4

VIN=20mVp-p

3


0.4

0.3

FREQUENCY(MHz)


MAX4225/MAX4226

GAIN MATCHINGvs. FREQUENCY (AVCL= +1)


VIN=2OmVp-p

FREQUENCY(MHz)


MAX4227/MAX4228

SMALL-SIGNALGAIN vs. FREQUENCY (AVCL= +2)

MAX4223-08

MAX4223-09

4

VIN=20mVp-p

3

AVCL=+1V/V

2 RF=560

1

GAIN(dB)

0

-1

-2

-3

-4

-5

-6

1 10


100 1000


0.2

0.1

GAIN(dB)

0

-0.1

-0.2

-0.3

-0.4

-0.5

-0.6

AVCL=+1V/V RF=560


1

AMPLIFIERA


AMPLIFIERB


10 100

AVCL=+2V/V

NORMALIZEDGAIN(dB)

2 RF=RG=470

1

0

-1

-2

-3

-4

-5

-6

1 10


100 1000


0.4

0.3

NORMALIZEDGAIN(dB)

0.2

0.1

0

-0.1

-0.2

-0.3

-0.4

-0.5

-0.6

FREQUENCY(MHz)


MAX4227/MAX4228

GAIN MATCHINGvs. FREQUENCY (AVCL= +2)

VIN=20mVp-p AVCL=+2V/V RF=RG=470


0

MAX4223-10

-10

-20

CROSSTALK(dB)

-30

-40

-50

-60

-70

-80

-90

-100

FREQUENCY(MHz)


MAX4225/MAX4226 CROSSTALK vs. FREQUENCY


RS=50 VOUT=2Vp-p


0

MAX4223-11

-10

-20

CROSSTALK(dB)

-30

-40

-50

-60

-70

-80

-90

-100

FREQUENCY(MHz)


MAX4223-12

MAX4227/MAX4228 CROSSTALK vs. FREQUENCY


RS=50 VOUT=2Vp-p

0.1 1

10 100

1 10

100 1000

1 10

100 1000

FREQUENCY(MHz)

FREQUENCY(MHz)

FREQUENCY(MHz)


MAX4223–MAX4228

PSRR(dB)

Typical Operating Characteristics (continued)

(VCC = +5V, VEE = -5V, RL = 100, TA = +25°C, unless otherwise noted.)


10

0

-10

-20

-30

-40

-50

-60

-70

-80

-90

MAX4223/MAX4225/MAX4226 POWER-SUPPLY REJECTIONRATIO

vs. FREQUENCY (AVCL= +1)


AVCL=+1V/V RF=560


VCC


VEE


10

MAX4223-13

0

-10

-20

PSRR(dB)

-30

-40

-50

-60

-70

-80

-90

MAX4224/MAX4227/MAX4228 POWER-SUPPLY REJECTIONRATIO

vs. FREQUENCY (AVCL= +2)


AVCL=+2V/V RF=RG=470


VCC


VEE


100


MAX4223-14

OUTPUTIMPEDANCE( )

10


1


0.1


0.01


OUTPUT IMPEDANCE vs. FREQUENCY


MAX4223-15

MAX4223/5/6 AVCL=+1V/V RF=560


MAX4224/7/8 AVCL=+2V/V RF=RG=470

0.01

0.1

1 10 100

FREQUENCY(MHz)

0.01

0.1

1 10 100

FREQUENCY(MHz)

0.01 0.1 1 10 100

FREQUENCY(MHz)


SHUTDOWNMODEOUTPUTISOLATION(dB)

20

0

-20


SHUTDOWN MODEOUTPUT ISOLATION vs. FREQUENCY


MAX4223-16

MAX4223/5/6 AVCL=+1V/V


-30


-40

MAX4223/MAX4225/MAX4226 TOTALHARMONICDISTORTION vs. FREQUENCY (RL = 150)


AVCL=+1V/V RL=150 RF=560


-30


MAX4223-17

-40

MAX4223/MAX4225/MAX4226 TOTALHARMONICDISTORTION vs. FREQUENCY (RL = 1k)


MAX4223-18

AVCL=+1V/V

RL=1k RF=560

-40

-60

-80

-100

RF=560


MAX4224/7/8

-50


THD(dBc)

-60

VOUT=2Vp-p


THD

-50


THD(dBc)

-60


-70

VOUT=2Vp-p

THD


-120

-140

-160

-180

AVCL=+2V/V RF=RG=470

-70


-80


-90


2NDHARMONIC


3RDHARMONIC


-80


-90


-100

2NDHARMONIC 3RDHARMONIC

0.01

0.1 1

10 100

1000

0.1 1

10 100

0.1 1

10 100


-30


-40


THD(dBc)

-50


-60


-70

FREQUENCY(MHz)

MAX4224/MAX4227/MAX4228 TOTALHARMONICDISTORTION vs. FREQUENCY (RL = 150)



D


T

H


-30


MAX4223-19

-40


-50


THD(dBc)

-60


-70


-80

FREQUENCY(MHz)

MAX4224/MAX4227/MAX4228 TOTALHARMONICDISTORTION vs. FREQUENCY (RL = 1k)


THD

2NDHARMONIC

FREQUENCY(MHz)


TWO-TONE THIRD-ORDER INTERCEPT vs. FREQUENCY

MAX4223-20

MAX4223-21

55


THIRD-ORDERINTERCEPT(dBm)

50


45


40 MAX4224/7/8


35


30


-80

2NDHARMONIC

3RDHARMONIC


-90

MAX4223/5/6

3RDHARMONIC

25


-90


0.1 1


10 100


-100


0.1 1


10 100


20

10 20


30 40


50 60 70 80 90 100


MAX4223–MAX4228

Typical Operating Characteristics (continued)

(VCC = +5V, VEE = -5V, RL = 100, TA = +25°C, unless otherwise noted.)



+100mV INPUT


-100mV


+100mV OUTPUT

-100mV

MAX4223/MAX4225/MAX4226 SMALL-SIGNAL PULSERESPONSE

(AVCL= +1)

MAX4223-22


GND


GND


+100mV INPUT


-100mV


+100mV OUTPUT

-100mV

MAX4223/MAX4225/MAX4226 SMALL-SIGNAL PULSERESPONSE

(AVCL= +1, CL= 25pF)

MAX4223-23


GND


GND


+50mV INPUT

-50mV


+100mV OUTPUT

-100mV

MAX4224/MAX4227/MAX4228 SMALL-SIGNAL PULSERESPONSE

(AVCL= +2)

MAX4223-24


GND


GND


TIME(10ns/div)


TIME(10ns/div)

TIME(10ns/div)


MAX4224/MAX4227/MAX4228 SMALL-SIGNAL PULSERESPONSE

(AVCL= +2, CL= 10pF)

MAX4223-25

MAX4223/MAX4225/MAX4226 LARGE-SIGNAL PULSERESPONSE

(AVCL= +1)

MAX4223-26

MAX4223/MAX4225/MAX4226 LARGE-SIGNAL PULSERESPONSE

(AVCL= +1, CL= 25pF)

MAX4223-27


+50mV INPUT

-50mV


GND


+2V INPUT

-2V


GND

+2V INPUT

-2V


GND


+100mV OUTPUT

-100mV


GND


+2V OUTPUT

-2V

+2V GND OUTPUT

-2V


GND


TIME(10ns/div)


TIME(10ns/div)

TIME(10ns/div)


MAX4224/MAX4227/MAX4228 LARGE-SIGNAL PULSERESPONSE

(AVCL= +2)

MAX4223-28

MAX4224/MAX4227/MAX4228 LARGE-SIGNAL PULSERESPONSE

(AVCL= +2,CL = 10pF)

MAX4223-29

MAX4224/MAX4227/MAX4228 LARGE-SIGNAL PULSERESPONSE

(AVCL= +5)

MAX4223-30


+1V INPUT

-1V


GND

+1V INPUT

-1V


GND

+400mV INPUT

-400mV


GND


+2V OUTPUT

-2V


GND

+2V OUTPUT

-2V

+2V GND OUTPUT

-2V


GND


TIME(10ns/div)

TIME(10ns/div)

TIME(10ns/div)


MAX4223–MAX4228

CURRENT(mA)

Typical Operating Characteristics (continued)

(VCC = +5V, VEE = -5V, RL = 100, TA = +25°C, unless otherwise noted.)



POWER-SUPPLY CURRENT PERAMPLIFIER vs. TEMPERATURE

MAX4223-31

8 5

7

NORMAL 4

6 MODE

CURRENT( A)

5 3

4

3 2

2

SHUTDOWN 1

1 MODE

0 0


MAX4223-32

INPUT BIASCURRENT vs. TEMPERATURE



IB-


170


CURRENT(mA)

160


150


140


130


120


MAX4223-33

SHORT-CIRCUITOUTPUT CURRENT vs. TEMPERATURE










SINKING












SOURCING












IB+

-50

-25 0

25 50 75 100

-50

-25 0

25 50 75 100

-50

-25 0

25 50 75 100

TEMPERATURE(°C)


POSITIVEOUTPUT SWING vs. TEMPERATURE

MAX4223-34













RL=OPEN










RL=50






















4.5


POSITIVEOUTPUTSWING(V)

4.0


3.5


3.0


2.5


2.0


1.5

TEMPERATURE(°C)


-1.0


NEGATIVEOUTPUTSWING(V)

-1.5


-2.0


-2.5


-3.0


-3.5


-4.0

TEMPERATURE(°C)


MAX4223-35






















RL=50











RL=OPEN










NEGATIVEOUTPUT SWING vs. TEMPERATURE


1.0


-50


-25


0 25


50 75 100


-4.5


-50


-25


0 25


50 75 100

TEMPERATURE(°C) TEMPERATURE(°C)


MAX4223–MAX4228

Pin Description


PIN


NAME


FUNCTION FUNCTION

MAX4223/MAX4224

MAX4225 MAX4227

MAX4226/MAX4228

SOT23

SO

SO

µMAX

SO



1, 5




5, 7, 8, 10


N.C.

No Connect. Not internally connected. Tie to GND for optimum AC performance.

1

6

OUT

Amplifier Output


2


4


4


4


4

VEE

Negative Power-Supply Voltage. Connect to -5V.

3

3

IN+

Amplifier Noninverting Input

4

2

IN-

Amplifier Inverting Input


5


8





SHDN

Amplifier Shutdown. Connect to +5V for normal operation. Connect to GND for low- power shutdown.


6


7


8


10


14

VCC

Positive Power-Supply Voltage. Connect to +5V.

1

1

1

OUTA

Amplifier A Output

2

2

2

INA-

Amplifier A Inverting Input

3

3

3

INA+

Amplifier A Noninverting Input

5

7

11

INB+

Amplifier B Noninverting Input

6

8

12

INB-

Amplifier B Inverting Input

7

9

13

OUTB

Amplifier B Output





5


6


SHDNA

Amplifier A Shutdown Input. Connect to +5V for normal operation. Connect to GND for low-power shutdown mode.





6


9


SHDNB

Amplifier B Shutdown Input. Connect to +5V for normal operation. Connect to GND for low-power shutdown mode.


MAX4223–MAX4228


RG RF


IN-


RIN-

TZ OUT

+1


+1

IN+

MAX4223

VIN MAX4224

MAX4225

MAX4226

MAX4227 MAX4228

Detailed Description

The MAX4223–MAX4228 are ultra-high-speed, low- power, current-feedback amplifiers featuring -3dB bandwidths up to 1GHz, 0.1dB gain flatness up to 300MHz, and very low differential gain and phase errors of 0.01% and 0.02°, respectively. These devices operate on dual ± 5V or ± 3V power supplies and require only 6mA of supply current per amplifier. The MAX4223/MAX4225/MAX4226 are optimized for closed-loop gains of +1 (0dB) or more and have -3dB bandwidths of 1GHz. The MAX4224/MAX4227/ MAX4228 are optimized for closed-loop gains of +2 (6dB) or more, and have -3dB bandwidths of 600MHz (1.2GHz gain-bandwidth product).

The current-mode feedback topology of these ampli- fiers allows them to achieve slew rates of up to 1700V/µs with corresponding large signal bandwidths up to 330MHz. Each device in this family has an output that is capable of driving a minimum of 60mA of output current to ±2.5V.

Theory of Operation Since the MAX4223–MAX4228 are current-feedback amplifiers, their open-loop transfer function is expressed as a transimpedance:


Figure 1. Current-Feedback Amplifier


Low-Power Shutdown Mode

VOUT

IIN

or TZ

The MAX4223/MAX4224/MAX4226/MAX4228 have a

shutdown mode that is activated by driving the SHDN

input low. When powered from ±5V supplies, the SHDN

The frequency behavior of this open-loop transimped- ance is similar to the open-loop gain of a voltage-feed- back amplifier. That is, it has a large DC value and decreases at approximately 6dB per octave.

Analyzing the current-feedback amplifier in a gain con- figuration (Figure 1) yields the following transfer func- tion:

input is compatible with TTL logic. Placing the amplifier in shutdown mode reduces quiescent supply current to 350µA typical, and puts the amplifier output into a high- impedance state (100k typical). This feature allows these devices to be used as multiplexers in wideband systems. To implement the mux function, the outputs of multiple amplifiers can be tied together, and only the amplifier with the selected input will be enabled. All of

VOUT VIN


G x

TZS

TZS G x RIN

RF


VOS = input offset voltage (in volts)

1 + RF / RG = amplifier closed-loop gain (dimensionless) IB+ = input bias current (in amps)

IB- = inverting input bias current (in amps) RG = gain-setting resistor (in )

RF = feedback resistor (in ) RS = source resistor (in )

The following equation represents output noise density:


Figure 2. Output Offset Voltage


enOUT

1

RF x RG


With a 600MHz system bandwidth, this calculates to 250µVRMS (approximately 1.5mVp-p, using the six- sigma calculation).


where:

n S n

F G n

Communication Systems Nonlinearities of components used in a communication system produce distortion of the desired output signal.

in = input noise current density (in pA/Hz) en = input noise voltage density (in nV/Hz)

The MAX4223–MAX4228 have a very low, 2nV/Hz noise voltage. The current noise at the noninverting input (in+) is 3pA/Hz, and the current noise at the inverting input (in-) is 20pA/Hz.

An example of DC-error calculations, using the MAX4224 typical data and the typical operating circuit with RF = RG = 470 (RF  RG = 235) and RS = 50, gives:

VOUT = [5 x 10-4 x (1 + 1)] + [2 x 10-6 x 50 x (1 + 1)] +

[4 x 10-6 x 470]

VOUT = 3.1mV

Calculating total output noise in a similar manner yields the following:

Intermodulation distortion (IMD) is the distortion that results from the mixing of two input signals of different frequencies in a nonlinear system. In addition to the input signal frequencies, the resulting output signal contains new frequency components that represent the sum and difference products of the two input frequen- cies. If the two input signals are relatively close in fre- quency, the third-order sum and difference products will fall close to the frequency of the desired output and will therefore be very difficult to filter. The third-order intercept (IP3) is defined as the power level at which the amplitude of the largest third-order product is equal to the power level of the desired output signal. Higher third-order intercept points correspond to better lineari- ty of the amplifier. The MAX4223–MAX4228 have a typi- cal IP3 value of 42dBm, making them excellent choices for use in communications systems.

enOUT

1 1 x

3

x 1012


x 50 2

ADC Input Buffers Input buffer amplifiers can be a source of significant errors in high-speed ADC applications. The input buffer is usually required to rapidly charge and discharge the

12

2

9 2

ADC’s input, which is often capacitive (see the section


enOUT

20 x 10

10.2nV / Hz

x 235 2

x 10

Driving Capacitive Loads). In addition, a high-speed ADC’s input impedance often changes very rapidly during the conversion cycle, requiring an amplifier with


very low output impedance at high frequencies to main- tain measurement accuracy. The combination of high speed, fast slew rate, low noise, and low distortion makes the MAX4223–MAX4228 ideally suited for use as buffer amplifiers in high-speed ADC applications.

Video Line Driver The MAX4223–MAX4228 are optimized to drive coaxial transmission lines when the cable is terminated at both ends, as shown in Figure 3. Note that cable frequency response may cause variations in the signal’s flatness.

Driving Capacitive Loads A correctly terminated transmission line is purely resis- tive and presents no capacitive load to the amplifier. Although the MAX4223–MAX4228 are optimized for AC performance and are not designed to drive highly capacitive loads, they are capable of driving up to 25 pF without excessive ringing. Reactive loads decrease phase margin and may produce excessive ringing and oscillation (see Typical Operating Characteristics). Figure 4’s circuit reduces the effect of large capacitive loads. The small (usually 5 to 20) isolation resistor RISO, placed before the reactive load, prevents ringing and oscillation at the expense of a

small gain error. At higher capacitive loads, AC perfor- mance is limited by the interaction of load capacitance with the isolation resistor.

MAX4223–MAX4228

Maxim’s High-Speed Evaluation Board Layout

Figures 7 and 8 show a suggested layout for Maxim’s high-speed, single-amplifier evaluation boards. These boards were developed using the techniques described above. The smallest available surface-mount resistors were used for the feedback and back-termination resis- tors to minimize the distance from the IC to these resis- tors, thus reducing the capacitance associated with longer lead lengths.

SMA connectors were used for best high-frequency performance. Because distances are extremely short, performance is unaffected by the fact that inputs and outputs do not match a 50 line. However, in applica- tions that require lead lengths greater than 1/4 of the wavelength of the highest frequency of interest, con- stant-impedance traces should be used.

Fully assembled evaluation boards are available for the MAX4223 in an SO-8 package.



RG RF


IN-

RT

75 75 CABLE

OUT


75 CABLE

IN+

RT

MAX4223 75

RT MAX4224

75 MAX4225

MAX4226

MAX4227

MAX4228


RG RF


IN-


OUT RISO


IN+ CL RL

MAX4223

MAX4224

MAX4225 MAX4226 MAX4227 MAX4228

Figure 3. Video Line Driver

Figure 4. Using an Isolation Resistor (RISO) for High Capacitive Loads


MAX4223–MAX4228

MAX4223-fig5a

AC Testing/Performance AC specifications on high-speed amplifiers are usually guaranteed without 100% production testing. Since these high-speed devices are sensitive to external par- asitics introduced when automatic handling equipment is used, it is impractical to guarantee AC parameters through volume production testing. These parasitics are greatly reduced when using the recommended PC board layout (like the Maxim evaluation kit). Characterizing the part in this way more accurately rep- resents the amplifier’s true AC performance. Some

manufacturers guarantee AC specifications without clearly stating how this guarantee is made. The MAX4223–MAX4228 AC specifications are derived from worst-case design simulations combined with a sample characterization of 100 units. The AC perfor- mance distributions along with the worst-case simula- tion limits are shown in Figures 5 and 6. These distributions are repeatable provided that proper board layout and power-supply bypassing are used (see Layout and Power-Supply Bypassing section).


50

100UNITS

NUMBEROFUNITS

40


30 SIMULATION LOWERLIMIT


20

50

MAX4223-fig5b

100UNITS

NUMBEROFUNITS

40


30 SIMULATION LOWERLIMIT


20


10 10


0–600

650–700

750–800

850–900

950–1000

1050–1100

1150–1200

1250–1300

1350–1400

1450–1500

0–60

80–100

120–140

160–180

200–220

240–260

280–300

320–340

360–380

400–420

0 0


-3dBBANDWIDTH(MHz) ±0.1dBBANDWIDTH(MHz)


MAX4223-fig5c

Figure 5a. MAX4223 -3dB Bandwidth Distribution

Figure 5b. MAX4223 ±0.1dB Bandwidth Distribution



50

100UNITS

NUMBEROFUNITS

40


30 SIMULATION LOWERLIMIT


20


50

MAX4223-fig5d

100UNITS

NUMBEROFUNITS

40


30 SIMULATION LOWERLIMIT


20


10 10


0–800

825–850

875–900

925–950

975–1000

1025–1050

1075–1100

1125–1150

1175–1200

1225–1250

0–500

525–550

575–600

625–650

675–700

725–750

775–800

825–850

875–900

925–950

0 0


RISING-EDGESLEWRATE(V/s)


Figure 5c. MAX4223 Rising-Edge Slew-Rate Distribution

FALLING-EDGESLEWRATE(V/ s)


Figure 5d. MAX4223 Falling-Edge Slew-Rate Distribution


MAX4223–MAX4228

MAX4223-fig6a

MAX4223-fig6b










100UNITS














SIMULATION

LOWERLIMIT








































50 50

100UNITS

NUMBEROFUNITS

NUMBEROFUNITS

40 40

30 SIMULATION 30

LOWERLIMIT


20 20


10 10


0–200

250–300

350–400

450–500

550–600

650–700

750–800

850–900

950–1000

1050–1100

0–40

60–80

100–120

140–160

180–200

220–240

260–280

300–320

340–360

380–400

0 0


-3dBBANDWIDTH(MHz) ±0.1dBBANDWIDTH(MHz)


MAX4223-fig6c

Figure 6a. MAX4224 -3dB Bandwidth Distribution

Figure 6b. MAX4224 ±0.1dB Bandwidth Distribution


50

100UNITS

NUMBEROFUNITS

40


30 SIMULATION LOWERLIMIT


20

50

MAX4223-fig6d

100UNITS

NUMBEROFUNITS

40


30 SIMULATION LOWERLIMIT


20


10 10


0–1400

1425–1450

1475–1500

1525–1550

1575–1600

1625–1650

1675–1700

1725–1750

1775–1800

1825–1850

0–1100

1125–1150

1175–1200

1225–1250

1275–1300

1325–1350

1375–1400

1425–1450

1475–1500

1525–1550

0 0


RISING-EDGESLEWRATE(V/s)


Figure 6c. MAX4224 Rising-Edge Slew-Rate Distribution

FALLING-EDGESLEWRATE(V/ s)


Figure 6d. MAX4224 Falling-Edge Slew-Rate Distribution




MAX4223–MAX4228

Figure 7a. Maxim SOT23 High-Speed Evaluation Board Component Placement Guide—Component Side




Figure 7b. Maxim SOT23 High-Speed Evaluation Board PC Board Layout—Component Side

Figure 7c. Maxim SOT23 High-Speed Evaluation Board PC Board Layout—Back Side



MAX4223–MAX4228

Figure 8a. Maxim SO-8 High-Speed Evaluation Board Component Placement Guide—Component Side




Figure 8b. Maxim SO-8 High-Speed Evaluation Board PC Board Layout—Component Side

Figure 8c. Maxim SO-8 High-Speed Evaluation Board PC Board Layout—Back Side


14 VCC

13 OUTB

12 INB-

11 INB+

10 N.C.

9 SHDNB

8 N.C.

OUTA 1

INA- 2

INA+ 3

VEE 4

N.C. 5 SHDNA 6

N.C. 7

MAX

MAX4223–MAX4228

Pin Configurations (continued)


TOPVIEW


MAX4223 MAX4224

MAX4225 MAX4227


N.C. 1

8 SHDN

OUTA 1

8 VCC


IN- 2

7 VCC

INA- 2

7 OUTB


IN+ 3

6 OUT

INA+ 3

6 INB-


VEE 4

5 N.C.

VEE 4

5 INB+


SO

SO


MAX4226 MAX4228

MAX4226 MAX4228


OUTA 1

INA- 2

INA+ 3

VEE 4

SHDNA 5

10 VCC

9 OUTB

8 INB-

7 INB+

6 SHDNB


SO


_Ordering Infor mation (continued)

Chip Infor mation


MAX4223–MAX4228

PART

TEMP. RANGE

PIN- PACKAGE

SOT TOP MARK

MAX4224EUT-T

-40°C to

+85°C

6 SOT23

AAAE

MAX4224ESA

-40°C to

+85°C

8 SO

MAX4225ESA

-40°C to

+85°C

8 SO

MAX4226EUB

-40°C to

+85°C

10 µMAX

MAX4226ESD

-40°C to

+85°C

14 SO

MAX4227ESA

-40°C to

+85°C

8 SO

MAX4228EUB

-40°C to

+85°C

10 µMAX

MAX4228ESD

-40°C to

+85°C

14 SO

MAX4223/MAX4224 TRANSISTOR COUNT: 87 MAX4225–MAX4228 TRANSISTOR COUNT: 171 SUBSTRATE CONNECTED TO VEE


MAX4223–MAX4228

10LUMAXB.EPS

Package Infor mation











6LSOT.EPS

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

20 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600

© 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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