LP2989LV_15 Datasheet, PDF (11/26 Pages) Texas Instruments – Micropower and Low-Noise, 500-mA Ultra Low-Dropout Regulator for Use With Ceramic Output Capacitors

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8 Application and Implementation
LP2989LV
SNVS086K – MAY 2000 – REVISED JULY 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 LP2989LV is a linear voltage regulator operating from 2.1 V to 16 V on the input and regulates voltages
between 2.5 V to 5 V with 0.75% accuracy and 500-mA maximum output current. Efficiency is defined by the
ratio of output voltage to input voltage because the LP2989LV is a linear voltage regulator. To achieve high
efficiency, the dropout voltage (V_IN – V_OUT) must be as small as possible, thus requiring a very low dropout LDO.
Successfully implementing an LDO in an application depends on the application requirements. If the
requirements are simply input voltage and output voltage, compliance specifications (such as internal power
dissipation or stability) must be verified to ensure a solid design. If timing, start-up, noise, PSRR, or any other
transient specification is required, the design becomes more challenging.
8.2 Typical Application
*Capacitance values shown are minimum required to assure stability, but may be increased without limit. Larger
output capacitor provides improved dynamic response. See the Output Capacitor section.
**SHUTDOWN must be actively terminated (see the Shutdown Input Operation section). Tie to IN (pin 4) if not use.
Figure 12. Typical Application Schematic
8.2.1 Design Requirements
For typical linear regulator applications, use the parameters in Table 1
DESIGN PARAMETER
Input voltage
Output voltage
Output current
RMS noise, 100 Hz to 100 kHz
PSRR at 1 kHz
Table 1. Design Parameters
DESIGN REQUIREMENT
6.5 V, ±10%,
5 V, ±1%
500 mA (maximum), 1 mA (minimum)
18 μV_(RMS) typical
60 dB typical
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