Texas Instruments Evaluation Board for the LP38502 LP38502TJ-ADJEV LP38502TJ-ADJEV 数据表
产品代码
LP38502TJ-ADJEV
User's Guide
SNVA321A – January 2008 – Revised April 2013
AN-1782 LP38502TJ-ADJ Evaluation Board
1
Introduction
The LP38502TJ-ADJ is a 1.5A low-dropout (LDO) linear regulator in the thin TO-263 package that has an
adjustable output voltage (set by external resistors).
adjustable output voltage (set by external resistors).
2
Basic Application Circuit
The basic application circuit that is built up on the evaluation board is shown in
Figure 1. Basic Application Circuit
3
Changing the Output Voltage
The resistors R1 and R2 set the output voltage.
determines output voltage:
V
OUT
= V
ADJ
x (1 + R1/R2)
(1)
where V
ADJ
is typically 0.6 V.
The board has installed values of:
R1 = 19.1k
Ω
R2 = 6.04k
Ω
Which sets the output to 2.5 V. R1 can be adjusted to change the nominal output voltage to other values.
The minimum output voltage which can be set is the ADJ pin voltage, which is approximately 0.6 V. This is
obtained by installing a jumper or low value resistor (less than 10
The minimum output voltage which can be set is the ADJ pin voltage, which is approximately 0.6 V. This is
obtained by installing a jumper or low value resistor (less than 10
Ω
) at R1. The maximum usable output
voltage is limited by the maximum input voltage which is 5.5 V. Since rated dropout voltage at full current
is 0.375 V, this means the maximum usable output voltage for full current operation is about 5.1 V.
is 0.375 V, this means the maximum usable output voltage for full current operation is about 5.1 V.
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1
SNVA321A – January 2008 – Revised April 2013
AN-1782 LP38502TJ-ADJ Evaluation Board
Copyright © 2008–2013, Texas Instruments Incorporated