LD49150

Application hints

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Application hints

The LD49150 is an ultra-high performance, low dropout linear regulator, designed for high

current application that requires fast transient response. The LD49150 operates from two input

voltages, to reduce dropout voltage. The LD49150 is designed so that a minimum of external

component are necessary.

8.1

as 1.4V, allowing conversion from very low voltage supplies to achieve low output voltage levels

with very low power dissipation.

8.2

(3mA typ.) even at the maximum output current level (1.5A). A bypass capacitor on the bias pin

is recommended to improve the performance of the LD49150 during line and load transient.

injected into the control circuitry from the bias rail. In typical applications a 1µF ceramic chip

8.3

External capacitors

To assure regulator stability, input and output capacitors are required as shown in the typical

application circuit.

8.4

Output capacitor

The LD49150 requires a minimum output capacitance to maintain stability. A ceramic chip

capacitor of at least 1µF is required. However, specific capacitor selection could be needed to

ensure the transient response. A 1µF ceramic chip capacitor satisfies most applications but

output capacitors of, at least, 10µF in order to avoid over-voltage stress on the Input/output

power pins during short circuit conditions due to parasitic inductive effect. The output capacitor

must be located as close as possible to the output pin of the LD49150. The ESR (equivalent

series resistance) of the output capacitor must be within the "STABLE" region as shown in the

typical characteristics figures. Both ceramic and tantalum capacitors are suitable.

8.5

Minimum load current

The LD49150 does not require a minimum load to maintain output voltage regulation.