Datasheet

LP3878-ADJ
www.ti.com SNVS311B –MAY 2005–REVISED APRIL 2013
However, if the output is pulled above the input, this diode will turn ON and current will flow into the regulator
output.
In such cases, a parasitic SCR can latch which will allow a high current to flow into V
IN
(and out the ground pin),
which can damage the part.
In any application where the output may be pulled above the input, an external Schottky diode must be
connected from V
IN
to V
OUT
(cathode on V
IN
, anode on V
OUT
), to limit the reverse voltage across the LP3878-ADJ
to 0.3V (see Absolute Maximum Ratings).
SETTING THE OUTPUT VOLTAGE
The output voltage is set using resistors R1 and R2 (see Basic Application Circuit).
The formula for output voltage is:
V
OUT
= V
ADJ
x (1 + (R
1
/ R
2
)) (3)
R2 must be less than 5 kΩ to ensure loop stability.
To prevent voltage errors, R1 and R2 must be located near the LP3878-ADJ and connected via traces with no
other currents flowing in them (Kelvin connect). The bottom of the R1/R2 divider must be connected directly to
the LP3878-ADJ ground pin.
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