MAX4158ESA datasheet(13/16 Pages) MAXIM

13 / 16 page

350MHz/250MHz, 2-Channel

Video Multiplexer-Amplifiers

______________________________________________________________________________________

Driving Capacitive Loads

A correctly terminated transmission line is purely resis-

tive and presents no capacitive load to the amplifier.

Consequently, the MAX4158/MAX4159/MAX4258/

MAX4259 are optimized for AC performance and are

not designed to drive highly capacitive loads. Reactive

loads will decrease phase margin and may produce

excessive ringing and oscillation (see

Typical

Operating Characteristics). The circuit of Figure 4

reduces this problem. The small (usually 5

Ω to 20Ω)

isolation resistor RISO, placed before the reactive load,

prevents ringing and oscillation. At higher capacitive

loads, AC performance is limited by the interaction of

load capacitance with the isolation resistor.

MAX4158

MAX4159

MAX4258

MAX4259

IN_

RISO

OUT

MAX4158

MAX4159

MAX4258

MAX4259

INO

INI

OUT

Ω

Ω CABLE

Ω

Ω CABLE

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

Capacitive Loads

Figure 3. Video Line Driver

MAX4158ESA Datasheet(PDF) 13 Page - Maxim Integrated Products