Typical Performance Characteristics (Continued)
Total Harmonic Distortion vs. Frequency
01235031
Application Information
The LM6152/6154 is ideally suited for operation with about
10 kΩ(Feedback Resistor, R
F
) between the output and the
negative input terminal.
With R
F
set to this value, for most applications requiring a
close loop gain of 10 or less, an additional small compensa-
tion capacitor (C
F
) (see Figure 1) is recommended across R
F
in order to achieve a reasonable overshoot (10%) at the
output by compensating for stray capacitance across the
inputs.
The optimum value for C
F
can best be established experi-
mentally with a trimmer cap in place since its value is de-
pendant on the supply voltage, output driving load, and the
operating gain. Below, some typical values used in an invert-
ing configuration and driving a 10 kΩload have been tabu-
lated for reference:
TABLE 1. Typical BW (−3 dB) at Various
Supply Voltage and Gains
V
S
Volts
Gain C
F
pF
BW (−3 dB)
MHz
3
−1 5.6 4
−10 6.8 1.97
−100 None 0.797
24
−1 2.2 6.6
−10 4.7 2.2
−100 None 0.962
In the non-inverting configuration, the LM6152/6154 can be
used for closed loop gains of +2 and above. In this case,
also, the compensation capacitor (C
F
) is recommended
across R
F
(= 10 kΩ) for gains of 10 or less.
Because of the unique structure of this amplifier, when used
at low closed loop gains, the realizable BW will be much less
than the GBW product would suggest.
The LM6152/6154 brings a new level of ease of use to op
amp system design.
The greater than rail-to-rail input voltage range eliminates
concern over exceeding the common-mode voltage range.
The rail-to-rail output swing provides the maximum possible
dynamic range at the output. This is particularly important
when operating on low supply voltages.
The high gain-bandwidth with low supply current opens new
battery powered applications where higher power consump-
tion previously reduced battery life to unacceptable levels.
The ability to drive large capacitive loads without oscillating
functional removes this common problem.
To take advantage of these features, some ideas should be
kept in mind.
The LM6152/6154, capacitive loads do not lead to oscilla-
tions, in all but the most extreme conditions, but they will
result in reduced bandwidth. They also cause increased
settling time.
Unlike most bipolar op amps, the unique phase reversal
prevention/speed-up circuit in the input stage, caused the
slew rate to be very much a function of the input pulse
01235030
FIGURE 1. Typical Inverting Gain Circuit A
V
=−1
LM6152/LM6154
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