eorex

EP1084

Jul. 2006

www.eorex.com

5/8

Functional Block Diagram

Current

Limit

Thermal

Shutdown

FB

+

+-

+

1.25V

Introduction

The EP1084 adjustable Low Dropout (LDO) regulator is a 3 terminal device that can easily be

addition, the output voltage tolerances are also extremely tight and they include the transient response

as part of the specification. For example, Intel VRE specification calls for a total of

±100mV including

initial tolerance, load regulation and 0 to 5.0A load step.

The EP1084 is specifically designed to meet the fast current transient needs as well as providing an

accurate initial voltage, reducing the overall system cost with the need for fewer output capacitors.

Output Voltage Setting

R1 and R2 external resistors according to the following formula:

The EP1084 keeps a constant 1.25V between the output pin and the FB pin. By placing a resistor R1

output voltage. This is summarized in the above equation. Since the minimum load current requirement

of the EP1084 is 10mA, R1 is typically selected to be 121Ω resistor so that it automatically satisfies the

error to the output voltage and should only be considered when a very precise output voltage setting is

only 0.3% of the nominal set point.