LP2982 Datasheet, PDF (20/28 Pages) National Semiconductor (TI) – Micropower 50 mA Ultra Low-Dropout Regulator

LP2982
SNVS128K – MARCH 2000 – REVISED JUNE 2016
www.ti.com
9 Power Supply Recommendations
The LP2982 is designed to operate from an input voltage supply range between between V_OUT(NOM) + 1 V and
16 V. The input voltage range provides adequate headroom for the device to have a regulated output. This input
supply must be well regulated. If the input supply is noisy, additional input capacitors with low ESR can help
improve the output noise performance.
10 Layout
10.1 Layout Guidelines
For best overall performance, place all 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 inductive parasitics, 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 (or sink) heat from the LDO device. In most applications, this
ground plane is necessary to meet thermal requirements.
10.2 Layout Example
V_IN
C_IN
IN
OUT
C_OUT
V_OUT
Ground
GND
C_BYPASS
Ground
ON/ _BYPASS
OFF
Figure 42. LP2982 Layout Example
20
Submit Documentation Feedback
Product Folder Links: LP2982
Copyright © 2000–2016, Texas Instruments Incorporated