Datasheet Texas Instruments LP2980IM5-ADJ — 数据表

LP2980-ADJ
www.ti.com SNVS001E – APRIL 2000 – REVISED APRIL 2013 LP2980-ADJ Micropower 50 mA Ultra Low-Dropout
Adjustable Voltage Regulator in SOT-23
Check for Samples: LP2980-ADJ FEATURES DESCRIPTION The LP2980-ADJ is a 50 mA adjustable voltage
regulator designed to provide ultra low dropout in
battery powered applications. 1 2 Ultra Low Dropout Voltage
Output Adjusts from 1.23V to 15V
Specified 50 mA Output Current
Uses Tiny SOT-23 Package
Requires Few External Components 10Ω, and this
usually causes oscillation problems.
One caution about Tantalums if they are used on the input: the ESR of a Tantalum is low enough that it can be
destroyed by surge current if powered up from a low impedance source (like a battery) that has no limit on inrush
current. In these cases, use a ceramic input capacitor which does not have this problem.
CERAMIC: Ceramics are generally larger and more costly than Tantalums for a given amount of capacitance.
Also, they have a very low ESR which is quite stable with temperature. 8 Submit Documentation Feedback Copyright © 2000–2013, Texas Instruments Incorporated Product Folder Links: LP2980-ADJ LP2980-ADJ
www.ti.com SNVS001E – APRIL 2000 – REVISED APRIL 2013 Be warned that the ESR of a ceramic capacitor is typically low enough to make an LDO oscillate: a 2.2 μF
ceramic demonstrated an ESR of about 15 mΩ when tested. If used as an output capacitor, this will cause
instability (see ESR Curves).
If a ceramic is used on the output of an LDO, a small resistance (about 1Ω) should be placed in series with the
capacitor. If it is used as an input capacitor, no resistor is needed as there is no requirement for ESR on
capacitors used on the input. EXTERNAL RESISTORS
The output voltage is set using two external resistors (see Basic Application Circuit). It is recommended that the …