LMV822M National Semiconductor, LMV822M Datasheet - Page 12

• Manufacturer Part Number: LMV822M
• Description: Operational Amplifier (Op-Amp) IC
• Manufacturer: National Semiconductor

Specifications of LMV822M

• No. Of Amplifiers: 1
• Bandwidth: 5MHz
• Slew Rate: 2V/µs
• No. Of Pins: 8
• Single Supply Voltage Min (+v): 2.7V
• Amplifier Type: Operational
• Mounting Type: Surface Mount
• Peak Reflow Compatible (260 C): No
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Note
UNITY GAIN PULSE RESPONSE CONSIDERATION
A pull-up resistor is well suited for increasing unity-gain,
pulse response stability. For example, a 600 Ω pull-up resis-
tor reduces the overshoot voltage by about 50%, when
driving a 220 pF load. Figure 3 shows how to implement the
pull-up resistor for more pulse response stability.
Higher capacitances can be driven by decreasing the value
of the pull-up resistor, but its value shouldn’t be reduced
beyond the sinking capability of the part. An alternate ap-
proach is to use an isolation resistor as illustrated in Figure 4
.
Figure 5 shows the resulting pulse response from a LMV824,
while driving a 10,000 pF load through a 20Ω isolation
resistor.
FIGURE 4. Using an Isolation Resistor to Drive Heavy
FIGURE 3. Using a Pull-up Resistor at the Output for
FIGURE 2. Unity-Gain Frequency vs Common Mode
Stabilizing Capacitive Loads
Voltage for Various Loads
Capacitive Loads
(Continued)
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12
INPUT BIAS CURRENT CONSIDERATION
Input bias current (I
offset voltage. This offset is primarily due to I
through the negative feedback resistor, R
is 90 nA (max
mV will be developed (V
resistor (R
But the input offset current (I
offset voltage in the same manner - typically 0.05 mV at
room temp.
APPLICATION CIRCUITS
This section covers the following application circuits:
1. Telephone-Line Transceiver
2. “Simple” Mixer (Amplitude Modulator)
FIGURE 6. Canceling the Voltage Offset Effect of Input
FIGURE 5. Pulse Response per Figure 4
C
), as shown in Figure 6, cancels out this affect.
@
room) and R
B
) can develop a somewhat significant
Bias Current
OS
=I
F
B
OS
is 100 kΩ, then an offset of 9
x R
) will still contribute to an
F
).Using a compensation
F
. For example, if I
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B
flowing
B