LT1191 Linear Technology, LT1191 Datasheet - Page 10

• Manufacturer Part Number: LT1191
• Description: Ultra High Speed Operational Amplifier
• Manufacturer: Linear Technology

LT1191
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 SHDN
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 LT1191 in order to realize its full capability.
Although the LT1191 can drive a 30pF load, isolating the
capacitance with 10 can be helpful. Precautions prima-
rily have to do with driving large capacitive loads.
10
A
PPLICATI
An Unterminated Cable Is
a Large Capacitive Load
3
2
O
A
+
–
Driving Capacitive Load
V
LT1191
= –1, IN DEMO BOARD, C
U
–5V
5V
S
7
4
I FOR ATIO
U
6
COAX
L
= 30pF
W
LT1191 • TA11
U
A 1X Scope Probe Is a
Large Capacitive Load
Murphy Circuits
3
2
+
–
LT1191
–5V
5V
Other precautions include:
1. Use a ground plane (see Design Note 50, High Fre-
2. Do not use high source impedances. The input
3. PC board socket may reduce stability.
4. A feedback resistor of 1k or lower reduces the effects
7
4
quency Amplifier Evaluation Board).
capacitance of 2pF and R
an 8MHz – 3dB bandwidth.
of stray capacitance at the inverting input. (For in-
stance, closed-loop gain of 2 can use R
R
G
6
= 300 .)
1X SCOPE
PROBE
A
Driving Capacitive Load
V
WITH 10 ISOLATING RESISTOR
= –1, IN DEMO BOARD, C
A Scope Probe on the Inverting
Input Reduces Phase Margin
S
= 10k, for instance, will give
3
2
SCOPE
PROBE
+
–
L
LT1191
= 30pF
–5V
5V
7
4
FB
LT1191 • TA12
6
= 300 and
LT1191 • TA13