LMV796, LMV797

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SNOSAU9D – MARCH 2006 – REVISED MARCH 2013

APPLICATION INFORMATION

ADVANTAGES OF THE LMV796/LMV797

Wide Bandwidth at Low Supply Current

The LMV796 and LMV797 are high performance op amps that provide a unity gain bandwidth of 17 MHz while

drawing a low supply current of 1.15 mA. This makes them ideal for providing wideband amplification in portable

applications.

Low Input Referred Noise and Low Input Bias Current

The LMV796/LMV797 have a very low input referred voltage noise density (5.8 nV/

√Hz at 1 kHz). A CMOS input

stage ensures a small input bias current (100 fA) and low input referred current noise (0.01 pA/

√Hz). This is very

helpful in maintaining signal fidelity, and makes the LMV796 and LMV797 ideal for audio and sensor based

applications.

Low Supply Voltage

The LMV796 and the LMV797 have performance specified at 2.5V and 5V supply. The LMV796 family is

specified to be operational at all supply voltages between 2.0V and 5.5V, for ambient temperatures ranging from

−40°C to 125°C, thus utilizing the entire battery lifetime. The LMV796 and LMV797 are also specified to be

operational at 1.8V supply voltage, for temperatures between 0°C and 125°C. This makes the LMV796 family

ideal for usage in low-voltage commercial applications.

RRO and Ground Sensing

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

when operating at low supply voltages. An innovative positive feedback scheme is used to boost the current drive

capability of the output stage. This allows the LMV796 and the LMV797 to source more than 40 mA of current at

1.8V supply. This also limits the performance of the LMV796 family as comparators, and hence the usage of the

LMV796 and the LMV797 in an open-loop configuration is not recommended. The input common-mode range

includes the negative supply rail which allows direct sensing at ground in single supply operation.

Small Size

The small footprint of the LMV796 and the LMV797 package saves space on printed circuit boards, and enables

the design of smaller electronic products, such as cellular phones, pagers, or other portable systems. Long

traces between the signal source and the op amp make the signal path susceptible to noise. By using the

physically smaller LMV796 or LMV797 package, the op amp can be placed closer to the signal source, reducing

noise pickup and increasing signal integrity.

CAPACITIVE LOAD TOLERANCE

The LMV796 and LMV797 can directly drive 120 pF 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, the circuit in

Figure 45 can be used.

short circuit current.

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Product Folder Links: LMV796 LMV797