25˚C.) (Continued)

Application Notes

The LMV101/102/105/110 integrates a rail-to-rail op amp,

two internal gain-setting resistors and a V

one ultra tiny package, SC70-5 or SOT23-5. With its small

footprint and reduced component count for gain stage, it en-

ables the design of smaller portable electronic products,

such as cellular phones, pagers, PDAs, PCMCIA cards, etc.

In addition, the integration solution minimizes printed circuit

board stray capacitance, and reduces the complexity of cir-

cuit design.

The core op amp of this family is National’s LMV321.

1.0 Supply Bypassing

The application circuits in this datasheet do not show the

power supply connections and the associated bypass ca-

pacitors for simplification. When the circuits are built, it is al-

ways required to have bypass capacitors. Ceramic disc ca-

pacitors (0.1µF) or solid tantalum (1µF) with short leads, and

located close to the IC are usually necessary to prevent in-

terstage coupling through the power supply internal imped-

ance. Inadequate bypassing will manifest itself by a low fre-

quency

oscillation

or

by

high

frequency

instabilities.

Sometimes, a 10µF (or larger) capacitor is used to absorb

low frequency variations and a smaller 0.1µF disc is paral-

leled across it to prevent any high frequency feedback

through the power supply lines.

2.0 Input Voltage Range

The input voltage should be within the supply rails. The ESD

protection circuitry at the input of the device includes a diode

between the input pin and the negative supply pin. Driving

the input more than 0.6V (at 25˚C) beyond the negative sup-

ply will turn on the diode and cause signal distortions. For

applications that require sensing voltages beyond the nega-

tive rail, use the LMV111 with external gain setting resistors.

Inverting Small Signal Pulse Response

LMV105

DS101234-40

Inverting Small Signal Pulse Response

LMV110

DS101234-42

Slew Rate vs.

Supply Voltage

DS101234-43

www.national.com

8