LP3871_15 Datasheet, PDF (10/26 Pages) Texas Instruments – LP387x 0.8-A Fast Ultra-Low-Dropout Linear Regulators

LP3871, LP3874
SNVS225H – FEBRUARY 2003 – REVISED JUNE 2015
www.ti.com
Device Functional Modes (continued)
7.4.3 ERROR Flag Operation
The LP3871 produces logic low signals at the ERROR Flag pin when the output drops out of regulation due to
low input voltage, current limiting, or thermal limiting. This flag has a built-in hysteresis. The timing diagram in
Figure 10 shows the relationship between the ERROR flag and the output voltage. In this example, the input
voltage is changed to demonstrate the functionality of the ERROR Flag.
The internal ERROR flag comparator has an open drain output stage. Hence, the ERROR pin must be pulled
high through a pullup resistor. Although the ERROR flag pin can sink current of 1mA, this current is energy drain
from the input supply. Hence, the value of the pullup resistor must be in the range of 10 kΩ to 1 MΩ. The
ERROR pin must be connected to ground if this function is not used. It must also be noted that when the
shutdown pin is pulled low, the ERROR pin is forced to be invalid for reasons of saving power in shutdown
mode.
Figure 10. ERROR Flag Operation
10
Submit Documentation Feedback
Copyright © 2003–2015, Texas Instruments Incorporated
Product Folder Links: LP3871 LP3874