AME8815 Просмотр технического описания (PDF) - AME, Inc

Номер в каталоге

Компоненты Описание

производитель

AME8815

1.5A CMOS LDO

AME, Inc 

AME, Inc.

AME8815

n Detailed Description

The AME8815 family of CMOS regulators contain a

PMOS pass transistor, voltage reference, error amplifier,

over-current protection, and thermal shutdown.

The P-channel pass transistor receives data from the

error amplifier, over-current shutdown, and thermal pro-

tection circuits. During normal operation, the error ampli-

fier compares the output voltage to a precision reference.

Over-current and Thermal shutdown circuits become ac-

tive when the junction temperature exceeds 150oC, or

the current exceeds 2.2A. During thermal shutdown, the

output voltage remains low. Normal operation is restored

when the junction temperature drops below 120oC.

The AME8815 behaves like a current source when the

load reaches 2.2A. However, if the load impedance drops

below 0.3 ohms, the current drops back to 600mA to

prevent excessive power dissipation. Normal operation

is restored when the load resistance exceeds 0.75 ohms.

1.5A CMOS LDO

n External Capacitors

The AME8815 is stable with an output capacitor to

ground of 4.7µF or greater. Ceramic capacitors have the

lowest ESR, and will offer the best AC performance. Con-

versely, Aluminum Electrolytic capacitors exhibit the high-

est ESR, resulting in the poorest AC response. Unfortu-

nately, large value ceramic capacitors are comparatively

expensive. One option is to parallel a 0.1µF ceramic

capacitor with a 10µF Aluminum Electrolytic. The benefit

is low ESR, high capacitance, and low overall cost.

A second capacitor is recommended between the in-

put and ground to stabilize Vin. The input capacitor should

be at least 0.1µF to have a beneficial effect.

All capacitors should be placed in close proximity to

the pins. A "Quiet" ground termination is desirable. This

can be achieved with a "Star" connection.

11

Share Link: