LP38853_15 Datasheet, PDF (15/30 Pages) Texas Instruments – LP38853 3A Fast-Response High-Accuracy Adjustable LDO Linear Regulator with Enable and Soft-Start

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8 Application and Implementation
LP38853
SNVS335E – DECEMBER 2006 – REVISED NOVEMBER 2015
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The typical applications of the LP38853 include DSP supplies, microcontroller supplies, and post regulators.
Figure 23 shows the typical application circuit for LP38853.
8.2 Typical Application
VIN
VBIAS
VEN
GND
CIN
10 PF
CBIAS
1 PF
LP38853
IN
OUT
BIAS
EN
ADJ
SS
CSS
GND
CFF R1
VOUT
COUT
R2
10 PF
GND
Figure 23. LP38853 Typical Application
8.2.1 Design Requirements
For typical linear regulator applications, use the parameters listed in Table 2.
DESIGN PARAMETER
Input voltage
Output voltage
Output current
Table 2. Design Parameters
EXAMPLE VALUE
1.8 V
0.8 V
3A
8.2.2 Detailed Design Procedure
8.2.2.1 External Capacitors
To assure regulator stability, input and output capacitors are required as shown in the Figure 23.
8.2.2.1.1 Input Capacitor
The input capacitor must be at least 10 µF, but can be increased without limit. Its purpose is to provide a low
source impedance for the regulator input. A ceramic capacitor, X5R or X7R, is recommended.
Tantalum capacitors may also be used at the input pin. There is no specific equivalent series resistance (ESR)
limitation on the input capacitor (the lower, the better).
Aluminum electrolytic capacitors can be used, but are not recommended as their ESR increases very quickly at
cold temperatures. They are not recommended for any application where the ambient temperature falls below
0°C.
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