LMV721-N, LMV722-N

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SNOS414I – AUGUST 1999 – REVISED AUGUST 2013

APPLICATION NOTES

BENEFITS OF THE LMV721-N/722 SIZE

The small footprints of the LMV721-N/722 packages save space on printed circuit boards, and enable the design

of smaller electronic products, such as cellular phones, pagers, or other portable systems. The low profile of the

LMV721-N/722 make them possible to use in PCMCIA type III cards.

Signal Integrity Signals can pick up noise between the signal source and the amplifier. By using a physically

smaller amplifier package, the LMV721-N/722 can be placed closer to the signal source, reducing noise

pickup and increasing signal integrity.

Simplified Board Layout These products help you to avoid using long pc traces in your pc board layout. This

means that no additional components, such as capacitors and resistors, are needed to filter out the

unwanted signals due to the interference between the long pc traces.

Low Supply Current These devices will help you to maximize battery life. They are ideal for battery powered

systems.

Low Supply Voltage TI provides ensured performance at 2.2V and 5V. These specifications ensure operation

throughout the battery lifetime.

Rail-to-Rail Output Rail-to-rail output swing provides maximum possible dynamic range at the output. This is

particularly important when operating on low supply voltages.

Input Includes Ground Allows direct sensing near GND in single supply operation.

Protection should be provided to prevent the input voltages from going negative more than

−0.3V (at 25°C). An

input clamp diode with a resistor to the IC input terminal can be used.

CAPACITIVE LOAD TOLERANCE

The LMV721-N/722 can directly drive 4700pF in unity-gain without oscillation. The unity-gain follower is the most

sensitive configuration to capacitive loading. Direct capacitive loading reduces the phase margin of amplifiers.

The combination of the amplifier's output impedance and the capacitive load induces phase lag. This results in

either an underdamped pulse response or oscillation. To drive a heavier capacitive load, circuit in Figure 23 can

be used.

Figure 23. Indirectly Driving A capacitive Load Using Resistive Isolation

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Product Folder Links: LMV721-N LMV722-N