ST2L05

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an ESR value lower than the minimum required by the ST2L05 and their relatively large capacitance can

change a lot depending on the ambient temperature.The test results of the ST2L05 stability using

multilayer ceramic capacitors show that a minimum value of 2.2µF is needed for both regulators. This

value can be increased without limit if the input capacitor value is major or equal to 4.7µF, and up to 10µF

if the input capacitor is minor than 4.7µF.Surface-mountable solid tantalum capacitors offer a good

combination of small physical size for the capacitance value and ESR in the range needed by the ST2L05.

The test results show good stability for both outputs with values of at least 1µF. The value can be

increased without limit for even better performance such as transient response and noise.

IMPORTANT:

The output capacitor must maintain its ESR in the stable region over the full operating temperature to

assure stability. More over, capacitor tolerance and variations due to temperature must be considered to

assure that the minimum amount of capacitance is provided at all times. For this reason, when a Ceramic

multilayer capacitor is used, the better choice for temperature coefficient is the X7R type, which holds the

capacitance within ±15%. The output capacitor should be located not more than 0.5" from the output pins

of the device and returned to a clean analog ground.

ADJUSTABLE REGULATOR

The ST2L05 has a 1.25V reference voltage between the output and the adjust pins (respectively pin 4 and

temperature conditions.

Figure 6: Application Circuit