AD795KN Analog Devices, AD795KN Datasheet - Page 8

• Manufacturer Part Number: AD795KN
• Description: Low Power/ Low Noise Precision FET Op Amp
• Manufacturer: Analog Devices

AD795
MINIMIZING INPUT CURRENT
The AD795 is guaranteed to 1 pA max input current with 15
volt supply voltage at room temperature. Careful attention to
how the amplifier is used will maintain or possibly better this
performance.
The amplifier’s operating temperature should be kept as low as
possible. Like other JFET input amplifier’s, the AD795’s input
V
V
IN
IN
Figure 27. Unity Gain Follower
Figure 24. Unity Gain Inverter
10k
2
3
AD795
–V
2
3
4
S
+V
7
AD795
0.1 F
10k
–V
S
4
S
+V
0.1 F
7
0.1 F
S
10k
6
0.1 F
R
L
10k
6
R
L
C
100pF
L
V
OUT
C
100pF
L
V
OUT
100
90
10
0%
100
90
10
0%
Figure 25. Unity Gain Inverter
Large Signal Pulse Response
Figure 28. Unity Gain Follower
Large Signal Pulse Response
20V
20V
5V
5V
–8–
current will double for every 10 C rise in junction temperature
(illustrated in Figure 6). On-chip power dissipation will raise the
device operating temperature, causing an increase in input
current. Reducing supply voltage to cut power dissipation will
reduce the AD795’s input current (Figure 4). Heavy output
loads can also increase chip temperature, maintaining a
minimum load resistance of 10 k is recommended.
5 s
5 s
100
90
10
0%
100
90
10
0%
Figure 29. Unity Gain Follower
Small Signal Pulse Response
Figure 26. Unity Gain Inverter
Small Signal Pulse Response
10mV
20mV
500ns
500n s
REV. A