2

Application Information

Typical User Application:

Output Voltage Programming

The output voltage of the regulator can be programmed with

two external resistors and is described by the following

Output Current Limit Programming

The output current limit threshold of the regulator can be

programmed with a single external resistor connected from

Capacitor Selection

An input capacitor is required if the regulator is located more

than 6 inches from power supply filter capacitors. A 10µF

solid tantalum capacitor is recommended.

An output capacitor of at least 10µF must be used to insure

stability of the regulator. Additional capacitance may be

added as required to improve the dynamic response of the

regulator. Solid tantalum and/or ceramic capacitors are

recommended.

Loop Compensation

The output capacitor and ESR comprise a zero in the loop

transfer function that must be compensated with a pole to

insure loop stability in accordance with the following

capacitor should be a low ESR ceramic type.

Layout Guidelines

The stability of the regulator is sensitive to layout. It is

strongly recommended that a continuous copper ground

plane (1 ounce or greater) be used. In addition, component

lead lengths and interconnects should be minimized, but

should not exceed 1/2 inch. Finally, the return lead of the

as possible to the GND pin of the IC.

ISL72991RH

VIN

ILIM

SD

GND

VOUT

ADJ

VIN

VOUT

FIGURE 1. TYPICAL APPLICATION SCHEMATIC

ISL72991RH