LP3878 NSC [National Semiconductor], LP3878 Datasheet - Page 10

• Manufacturer Part Number: LP3878
• Description: Micropower 800mA Low Noise Ceramic Stable Voltage Regulator for Low Voltage Applications Designed for Use with Very Low ESR Output Capacitors
• Manufacturer: NSC [National Semiconductor]

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Application Hints
To assure proper operation, the signal source used to drive
the Shutdown input must be able to swing above and below
the specified turn-on/turn-off voltage thresholds listed in the
Electrical Characteristics section under V
REVERSE INPUT-OUTPUT VOLTAGE
The PNP power transistor used as the pass element in the
LP3878 has an inherent diode connected between the regu-
lator output and input.
During normal operation (where the input voltage is higher
than the output) this diode is reverse-biased.
(Continued)
ON/OFF
.
10
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
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
reverse voltage across the LP3878 to 0.3V (see Absolute
Maximum Ratings).
IN
to V
OUT
(cathode on V
IN
IN
(and out the ground pin), which
, anode on V
OUT
), to limit the