VOUT

VIN

GND

IN

GND

OUT

2

1

3

LM3480

www.ti.com

SNVS011H – JUNE 1999 – REVISED SEPTEMBER 2015

9 Power Supply Recommendations

The LM3480 is designed to operated from up to a 30-V input voltage supply. This input supply must be well

regulated. If the input supply is noisy, additional input capacitors with low ESR can help to improve the output

noise performance.

10 Layout

10.1 Layout Guidelines

For best overall performance, place all the circuit components on the same side of the circuit board and as near

as practical to the respective LDO pin connections. Place ground return connections to the input and output

capacitors, and to the LDO ground pin as close to each other as possible, connected by a wide, component-side,

copper surface. The use of vias and long traces to create LDO circuit connections is strongly discouraged and

negatively affects system performance. This grounding and layout scheme minimizes the inductive parasitic, and

thereby reduces load-current transients, minimizes noise, and increases circuit stability.

A ground reference plane is also recommended and is either embedded in the PCB itself or located on the

bottom side of the PCB opposite the components. This reference plane serves to assure accuracy of the output

voltage, shield noise, and behaves similar to a thermal plane to spread heat from the LDO device. In most

applications, this ground plane is necessary to meet thermal requirements.

10.2 Layout Example

Copyright © 1999–2015, Texas Instruments Incorporated

Submit Documentation Feedback

13

Product Folder Links: LM3480