OP215_15 Datasheet, PDF (7/8 Pages) Analog Devices – Dual Precision JFET-Input Operational Amplifier

OP215
APPLICATIONS INFORMATION
Dynamic Operating Considerations
As with most amplifiers, care should be taken with lead dress,
component placement, and supply de-coupling in order to ensure
stability. For example, resistors from the output to an input should
be placed with the body close to the input to minimize “pick up”
and maximize the frequency of the feedback pole by minimizing
the capacitance from the input to ground.
A feedback pole is created when the feedback around any amplifier
is resistive. The parallel resistance and capacitance from the
input of the device (usually the inverting input) to ac ground
sets the frequency of the pole. In many instances, the frequency
of this pole is much greater than the expected 3 dB frequency of
the closed-loop gain and, consequently, there is negligible effect
on stability margin. However, if the feedback pole is less than
approximately six times the expected 3 dB frequency, a lead
capacitor should be placed from the output to the negative input
of the op amp. The value of the added capacitor should be such
that the RC time constant of this capacitor and the resistance it
parallels is greater than, or equal to, the original feedback pole
time constant.
BASIC CONNECTIONS
100k⍀
200⍀
+15V
6
8
OP215 ⁷
5B
100k⍀
2
OP215
1
3A
4
–15V
NOTES
1. T_A = 125؇C TO 150؇C
2. RESISTORS ARE TYPE
RN55D, ؎ 1%
Figure 5. Burn-In Circuit
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
8-Lead CERDIP
(Z-Suffix)
0.005 (0.13) 0.055 (1.4)
MIN
MAX
8
PIN 1
1
5
0.310 (7.87)
0.220 (5.59)
4
0.100 (2.54) BSC
0.405 (10.29) MAX
0.200 (5.08)
MAX
0.200 (5.08)
0.125 (3.18)
0.060 (1.52)
0.015 (0.38)
0.150
(3.81)
MIN
0.023 (0.58)
0.070
(1.78)
SEATING
PLANE
0.014 (0.36) 0.030 (0.76)
0.320 (8.13)
0.290 (7.37)
0.015 (0.38)
15°
0.008 (0.20)
0°
8-Lead Plastic DIP
(P-Suffix)
0.430 (10.92)
0.348 (8.84)
8
5
0.280 (7.11)
0.240 (6.10)
1
4
PIN 1
0.100 (2.54)
0.325 (8.25)
0.300 (7.62)
BSC
0.060 (1.52)
0.210
(5.33)
MAX
0.015 (0.38)
0.130
0.195 (4.95)
0.115 (2.93)
0.160 (4.06)
(3.30)
0.115 (2.93)
MIN
0.015 (0.381)
0.022 (0.558) 0.070 (1.77) SEATING
0.014 (0.356) 0.045 (1.15) ^PLANE
0.008 (0.204)
REV. A
–7–