LM308A ON Semiconductor, LM308A Datasheet - Page 4

• Manufacturer Part Number: LM308A
• Description: SUPER GAIN OPERATIONAL AMPLIFIER
• Manufacturer: ON Semiconductor

circuit boards to take full advantage of the low input currents
of the LM308A amplifier. Boards must be thoroughly cleaned
with alcohol and blown dry with compressed air. After
cleaning, the boards should be coated with epoxy or silicone
rubber to prevent contamination.
Input
(1) Used to compensate for large source resistances.
4
Special care must be taken in the assembly of printed
(1) Power Bandwidth: 250 kHz
(2) C5 =
Input
Small Signal Bandwidth:
Slew Rate: 10 V/ s
Figure 7. Fast (1) Summing Amplifier with
150 k
3.5 MHz
RS
6 X 10 –8
Inverting Amplifier
R1
R1
R1
0.002 F
LM308A
R3 (1)
INPUT GUARDING
Low Input Current
Compen B
300 pF
R2
C1
1 M
R2
(3) In addition to increasing speed,
the LM101A raises high and low
frequency gain, increases output
drive capability and eliminates
thermal feedback.
Output
1.0 M
0.002
2
3
F
C5 (2)
R4
SUGGESTED DESIGN APPLICATIONS
1
LM101A (3)
150 pF
Figure 9. Connection of Input Guards
or equiv
6
Input
Output
R3 (1)
Follower
LM308A
C1
currents may cause trouble at +125 C, particularly since the
input pins are adjacent to pins that are at supply potentials.
This leakage can be significantly reduced by using guarding
to lower the voltage difference between the inputs and
adjacent metal runs. The guard, which is a conductive ring
surrounding the inputs, is connected to a low–impedance
point that is at approximately the same voltage as the inputs.
Leakage currents from high voltage pins are then absorbed
by the guard.
Even with properly cleaned and coated boards, leakage
Output
Sample
Input
(1) Teflon, Polyethylene or Polycarbonate
Figure 8. Sample and Hold
1.0 F (1)
Note:
V CC
MOTOROLA ANALOG IC DEVICE DATA
Dielectric Capacitor
Q1
Q2
R1 +R2
R1
R1 R2
Noninverting Amplifier
R3 (1)
Input
1.0 M
must be an impedance.
R2
C1
30 pF
Output
Output