LMC6462BIM/NOPB National Semiconductor, LMC6462BIM/NOPB Datasheet - Page 12

IC OP AMP DUAL MICPWR R-R 8-SOIC

LMC6462BIM/NOPB

Manufacturer Part Number
LMC6462BIM/NOPB
Description
IC OP AMP DUAL MICPWR R-R 8-SOIC
Manufacturer
National Semiconductor
Datasheet

Specifications of LMC6462BIM/NOPB

Amplifier Type
General Purpose
Number Of Circuits
2
Output Type
Rail-to-Rail
Slew Rate
0.028 V/µs
Gain Bandwidth Product
50kHz
Current - Input Bias
0.15pA
Voltage - Input Offset
250µV
Current - Supply
50µA
Current - Output / Channel
75mA
Voltage - Supply, Single/dual (±)
3 V ~ 15.5 V, ±1.5 V ~ 7.75 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
8-SOIC (3.9mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
-3db Bandwidth
-
Other names
*LMC6462BIM
*LMC6462BIM/NOPB
LMC6462BIM
www.national.com
Application Information
The pulse response of the circuit shown in Figure 6 is shown
in Figure 7.
4.0 COMPENSATING FOR INPUT CAPACITANCE
It is quite common to use large values of feedback resis-
tance with amplifiers that have ultra-low input current, like
the LMC6462/4. Large feedback resistors can react with
small values of input capacitance due to transducers, pho-
todiodes, and circuits board parasitics to reduce phase mar-
gins.
FIGURE 8. Canceling the Effect of Input Capacitance
FIGURE 6. LMC6462 Non-Inverting Amplifier,
Compensated to Handle a 300 pF Capacitive
FIGURE 7. Pulse Response of
LMC6462 Circuit in Figure 6
and 100 kΩ Resistive Load
(Continued)
01205111
01205112
01205110
12
The effect of input capacitance can be compensated for by
adding a feedback capacitor. The feedback capacitor (as in
Figure 8 ), C
or
which typically provides significant overcompensation.
Printed circuit board stray capacitance may be larger or
smaller than that of a breadboard, so the actual optimum
value for C
checked on the actual circuit. (Refer to the LMC660 quad
CMOS amplifier data sheet for a more detailed discussion.)
5.0 OFFSET VOLTAGE ADJUSTMENT
Offset voltage adjustment circuits are illustrated in Figure 9
and Figure 10. Large value resistances and potentiometers
are used to reduce power consumption while providing typi-
cally
both configurations with V
6.0 SPICE MACROMODEL
A Spice macromodel is available for the LMC6462/4. This
model includes a simulation of:
• Input common-mode voltage range
• Frequency and transient response
• GBW dependence on loading conditions
• Quiescent and dynamic supply current
• Output swing dependence on loading conditions
±
2.5 mV of adjustment range, referred to the input, for
FIGURE 10. Non-Inverting Configuration
F
FIGURE 9. Inverting Configuration
F
may be different. The values of C
, is first estimated by:
Offset Voltage Adjustment
Offset Voltage Adjustment
R
1
C
S
IN
=
≤ R
±
5V.
2
C
F
F
01205113
should be
01205114

Related parts for LMC6462BIM/NOPB