_______________Detailed Description

The MAX4200–MAX4205 wide-band, open-loop buffers

feature high slew rates, high output current, low

2.1nV

√Hz voltage-noise density, and excellent capaci-

tive-load-driving capability. The MAX4200/MAX4203

are single/dual buffers with up to 660MHz bandwidth,

230MHz 0.1dB gain flatness, and a 4200V/µs slew rate.

The MAX4201/MAX4204 single/dual buffers with inte-

grated 50

Ω output termination resistors, up to 780MHz

bandwidth, 280MHz gain flatness, and a 4200V/µs slew

rate, are ideally suited for driving high-speed signals

over 50

Ω cables. The MAX4202/MAX4205 provide

bandwidths up to 720MHz, 230MHz gain flatness,

4200V/µs slew rate, and integrated 75

Ω output termina-

tion resistors for driving 75

Ω cables.

With an open-loop gain that is slightly less than +1V/V,

these devices do not have to be compensated with the

internal dominant pole (and its associated phase shift)

that is present in voltage-feedback devices. This fea-

ture allows the MAX4200–MAX4205 to achieve a nearly

constant group delay time of 405ps over their full fre-

quency range, making them well suited for a variety of

RF and IF signal-processing applications.

These buffers operate with ±5V supplies and consume

only 2.2mA of quiescent supply current per buffer while

providing up to ±90mA of output current drive capability.

__________Applications Information

Power Supplies

The MAX4200–MAX4205 operate with dual supplies

bypassed to the ground plane with a 0.1µF capacitor

located as close to the device pin as possible.

Layout Techniques

Maxim recommends using microstrip and stripline tech-

niques to obtain full bandwidth. To ensure that the PC

board does not degrade the amplifier’s performance,

design it for a frequency greater than 6GHz. Pay care-

ful attention to inputs and outputs to avoid large para-

sitic capacitance. Whether or not you use a

constant-impedance board, observe the following

guidelines when designing the board:

• Do not use wire-wrap boards, because they are too

inductive.

• Do not use IC sockets, because they increase para-

sitic capacitance and inductance.

Ultra-High-Speed, Low-Noise, Low-Power,

SOT23 Open-Loop Buffers

8

_______________________________________________________________________________________

______________________________________________________________Pin Description

Not Internally Connected

N.C.

1

1, 2, 5, 8

—

Buffer Input

IN

3

3

—

Buffer 1 Input

IN1

—

—

1

Buffer 1 Output

OUT1

—

—

2

Negative Power Supply

2

4

—

Negative Power Supply for Buffer 1

—

—

3

Negative Power Supply for Buffer 2

—

—

4

Buffer 2 Input

IN2

—

—

5

Buffer 2 Output

OUT2

—

—

6

Buffer Output

OUT

5

6

—

Positive Power Supply

4

7

—

Positive Power Supply for Buffer 2

—

—

7

Positive Power Supply for Buffer 1

—

—

8

NAME

FUNCTION

SOT23-5

SO

SO/µMAX

MAX4200/MAX4201/MAX4202

PIN

MAX4203

MAX4204

MAX4205