Tantalum Capacitors: Tantalum capacitors are the best choice for use with the LP2982. Most good quality tantalums can be used with the LP2982, but check the manufacturer's data sheet to be sure the ESR is in range. As the ESR increases at lower temperatures and a capacitor that is near the upper limit for stability at room temperature can cause instability when temperature gets cold.

In applications which must operate at very low temperatures, the output tantalum capacitor needs to be placed in parallel with a ceramic capacitor to prevent the ESR from going up too high (see ceramic capacitors discussion in this section for important information on ceramic capacitors).

Ceramic Capacitors: TI does not recommend use of ceramic capacitors at the output of the LP2982. This is because the ESR of a ceramic can be low enough to go below the minimum stable value for the LP2982. A 2.2μF ceramic was measured and found to have an ESR of about 15mΩ, which is low enough to cause oscillations. If a ceramic capacitor is used on the output, a 1Ω resistor must be placed in series with the capacitor.

Aluminum Capacitors: Because of large physical size, aluminum electrolytics are not typically used with the LP2982. The aluminum capacitors must meet the same ESR requirements over the operating temperature range, more difficult because of the ESR steep increase at cold temperature. An aluminum electrolytic can exhibit an ESR increase of as much as 50× when going from 20°C to −40°C. Also, some aluminum electrolytics are not operational below −25°C because the electrolyte can freeze.