10

LT1190

A 1X Scope Probe Is a

Large Capacitive Load

An Unterminated Cable Is

a Large Capacitive Load

Murphy Circuits

Driving Capacitive Load

Driving Capacitive Load

The ability to maintain shutoff is shown on the curve

Shutdown Supply Current vs Temperature in the Typical

Performance Characteristics section. At very high

elevated temperatures it is important to hold the shut-

down pin close to the negative supply to keep the supply

current from increasing.

Murphy Circuits

There are several precautions the user should take when

using the LT1190 in order to realize its full capability.

Although the LT1190 can drive a 50pF load, isolating the

capacitance with 10

Ω can be helpful. Precautions prima-

rily have to do with driving large capacitive loads.

Other precautions include:

1. Use a ground plane (see Design Note 50, High Fre-

quency Amplifier Evaluation Board).

2. Do not use high source impedances. The input

an 8MHz – 3dB bandwidth.

3. PC board socket may reduce stability.

4. A feedback resistor of 1k or lower reduces the effects of

stray capacitance at the inverting input. (For instance,

300

Ω.)

APPLICATIO S I FOR ATIO

LT1190 • TA13

COAX

5V

–5V

4

2

7

3

6

2

5V

7

–5V

4

3

6

SCOPE

PROBE

2

5V

7

–5V

4

3

6

1X SCOPE

PROBE

+

–

LT1190

+

–

LT1190

+

–

LT1190

A Scope Probe on the Inverting

Input Reduces Phase Margin

LT1190 • TA11

LT1190 • TA12

WITH 10

Ω ISOLATING RESISTOR