13

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

3021fa

APPLICATIO S I FOR ATIO

If the LT3021 is powered by a battery mounted in close

proximity on the same circuit board, a 3.3

µF input capaci-

tor is sufficient for stability. However, if the LT3021 is

powered by a distant supply, use a larger value input

capacitor following the guideline of roughly 1

µF (in addi-

tion to the 3.3

µF minimum) per 8 inches of wire length. As

power supply output impedance may vary, the minimum

input capacitance needed to stabilize the application may

also vary. Extra capacitance may also be placed directly on

the output of the power supply; however, this will require

an order of magnitude more capacitance as opposed to

placing extra capacitance in close proximity to the LT3021.

Furthermore, series resistance may be placed between the

supply and the input of the LT3021 to stabilize the appli-

cation; as little as 0.1

Ω to 0.5Ω will suffice.