 English |
|
|
|
|
|
|
|
| LP2981-N_16 Datasheet, PDF (18/30 Pages) Texas Instruments – Micropower 100-mA Ultralow Dropout Regulator | |||
| |||
| ◁ |
LP2981-N
SNOS773N â MARCH 2000 â REVISED APRIL 2016
LP2981-N
VIN
PNP
www.ti.com
VOUT
GND
Figure 34. LP2981-N Reverse Current Path
However, if the input voltage is more than a VBE below the output voltage, 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
the VIN pin and out the ground pin, which can damage the part.
The internal diode can also be turned on if the input voltage is abruptly stepped down to a voltage which is a VBE
below the output voltage.
In any application where the output voltage may be higher than the input voltage, an external Schottky diode
must be connected from VIN to VOUT (cathode on VIN, anode on VOUT; see Figure 35), to limit the reverse voltage
across the LP2981-N to 0.3 V (see Absolute Maximum Ratings).
SCHOTTKY DIODE
LP2981-N
VIN
PNP
VOUT
GND
Figure 35. Adding External Schottky Diode Protection
8.2.2.4 ON and OFF Input Operation
The LP2981-N is shut off by pulling the ON/OFF input low, and turned on by driving the input high. If this feature
is not to be used, the ON/OFF input should be tied to VIN to keep the regulator on at all times (the ON/OFF input
must not be left floating).
To ensure proper operation, the signal source used to drive the ON/OFF input must be able to swing above and
below the specified turnon/turnoff voltage thresholds which specify an ON or OFF state (see Electrical
Characteristics).
18
Submit Documentation Feedback
Product Folder Links: LP2981-N
Copyright © 2000â2016, Texas Instruments Incorporated
|
▷ |
German
Russian
Spanish
Italian
Polish
Chinese
Japanese
Korean
French
Portuguese