AD795

REV. A

–8–

10

90

100

5V

20V

5

µs

0%

Figure 25. Unity Gain Inverter

Large Signal Pulse Response

10

90

100

5V

20V

5

µs

0%

Figure 28. Unity Gain Follower

Large Signal Pulse Response

7

6

4

3

2

10k

Ω

V

IN

–V

S

0.1

µF

R

L

10k

Ω

V

OUT

10k

Ω

C

L

100pF

0.1

µF

+V

S

AD795

Figure 24. Unity Gain Inverter

7

6

4

3

2

V

IN

–V

S

0.1

µF

R

L

10k

Ω

V

OUT

C

L

100pF

0.1

µF

+V

S

AD795

Figure 27. Unity Gain Follower

10

90

100

10mV

500n s

0%

Figure 26. Unity Gain Inverter

Small Signal Pulse Response

10

90

100

20mV

500n s

0%

Figure 29. Unity Gain Follower

Small Signal Pulse Response

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

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

Ω is recommended.