Flash ADC Preamp

The MAX4178/MAX4278’s high current-drive capability

makes them well suited for buffering the low-imped-

ance input of a high-speed flash ADC. With their low

output impedance, these buffers can drive the inputs of

the ADC with no loss of accuracy. Figure 4 shows a

preamp for digitizing video, using the 250Msps

MAX100 and the 500Msps MAX101 flash ADCs. Both of

these ADCs have a 50

Ω input resistance and a 1.2GHz

input bandwidth.

High-Performance

Video Distribution Amplifier

The MAX4278 (AV = +2) makes an excellent driver for

multiple back-terminated 75

Ω video coaxial cables

(Figure 5). The high current-output capability allows the

attachment of up to six ±2Vp-p, 150

Ω loads to the

MAX4278 at +25°C. With the output limited to ±1Vp-p,

the number of loads may double. For multiple gain-of-2

video line drivers in a single package, see the

MAX496/MAX497data sheet.

330MHz, Gain of +1/Gain of +2

Closed-Loop Buffers

10

______________________________________________________________________________________

MAX4178

MAX4278

VIDEO IN

FLASH ADC

(MAX100/MAX101)

Figure 4. Preamp for Video Digitizer

MAX4278

VIDEO IN

75

Ω

75

Ω

75

Ω

75

Ω

75

Ω

75

Ω

75

Ω

75

Ω

75

Ω

OUT1

OUT2

OUTN

Figure 5. High-Performance Video Distribution Amplifier

___________________Chip Information

TRANSISTOR COUNT: 175

_Ordering Information (continued)

PART

MAX4278EPA

MAX4278ESA

MAX4278EUA

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

TEMP. RANGE

PIN-

PACKAGE

8 Plastic DIP

8 SO

8 µMAX

MAX4278MJA

-55°C to +125°C 8 CERDIP

MAX4278EUK-T

-40°C to +85°C

5 SOT23

SOT

TOP MARK

–

–

–

–

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