供应益力iD9301电源IC

Application Information

Capacitor Selection and Regulator

Stability

Input Capacitor

An input capacitance of 1μF is required between the

device input pin and ground directly (the amount of the

capacitance may be increased without limit). The input

capacitor MUST be located less than 1 cm from the

device to assure input stability (see PCB Layout

Section). A lower ESR capacitor allows the use of less

capacitance, while higher ESR type (like aluminum

electrolytic) requires more capacitance. Capacitor

types (aluminum, ceramic and tantalum) can be mixed

in parallel, but the total equivalent input

capacitance/ESR must be defined as above for stable

operation. There are no requirements for the ESR on

the input capacitor, but tolerance and temperature

coefficient must be considered when selecting the

capacitor to ensure the capacitance is 1 μF over the

entire operating range.

Output Capacitor

The iD9301 is designed specifically to work with very

small ceramic output capacitors. The minimum

capacitance recommended (temperature

characteristics of X7R, X5R, Z5U or Y5V) is within the

1μF to 10μF range with 5mΩ to 50mΩ ESR range

ceramic capacitor between LDO output and GND for

transient stability, but it may be increased without limit.

Higher capacitance values help to improve transient

response. The output capacitor's ESR is critical

because it forms a zero to provide phase lead which is

required for loop stability.

Enable Function

The iD9301 is shut down by pulling the EN pin low, and

turned on by driving the input high. If the shutdown

feature is not required, the EN pin should be tied to

VIN to keep the regulator on at all times (the EN pin

MUST NOT be left floating).