0

1.0

2.0

_

3.0

_

4.0

_

5.0

_

DC Bias (V)

100%

80%

60%

40%

20%

_

0402, 6.3V, X5R

0603, 10V, X5R

LP5990

www.ti.com

SNVS438B – APRIL 2007 – REVISED DECEMBER 2007

Another important consideration is that tantalum capacitors have higher ESR values than equivalent size

ceramics. This means that while it may be possible to find a tantalum capacitor with an ESR value within the

stable range, it would have to be larger in capacitance (which means bigger and more costly) than a ceramic

capacitor with the same ESR value. It should also be noted that the ESR of a typical tantalum will increase about

2:1 as the temperature goes from 25°C down to

−40°C, so some guard band must be allowed.

Figure 2.

NO-LOAD STABILITY

The LP5990 will remain stable and in regulation with no external load.

ENABLE CONTROL

turn the device on. When the enable pin is low, the regulator output is off and the device typically consumes 3

regulator output permanently on.

micro SMD MOUNTING

The micro SMD package requires specific mounting techniques, which are detailed in National Semiconductor

Application Note AN-1112.

For best results during assembly, alignment ordinals on the PC board may be used to facilitate placement of the

micro SMD device.

micro SMD LIGHT SENSITIVITY

Exposing the micro SMD device to direct light may cause incorrect operation of the device. Light sources such as

halogen lamps can affect electrical performance if they are situated in proximity to the device.

Light with wavelengths in the red and infra-red part of the spectrum have the most detrimental effect thus the

fluorescent lighting used inside most buildings has very little effect on performance.

Copyright © 2007, Texas Instruments Incorporated

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