He
epc701/epc703
Functional Description
Normal Operation
During typical operation the OUT follows the IN as shown in Figure 1. In the the other state (when IN is set to high level), the internal switch is
closed pulling the OUT pin to VDD. As long as the output current does not exceed the current threshold, OUT is stable ON and STATUS is
stable HIGH-Z. The delay from IN to OUT is defined as tON and tOFF for the rising and the falling edge respectively.
0
IN
OUT (without
external Transistor
VDD-⎮V
⎮
Sat
HIGH-Z
VDD
OUT (with
external Transistor
0
toff
ton
0
SHORT
SENS
VDD
Vth sens
HIGH-Z
HIGH-Z
STATUS
epc700
STATUS
epc702
Figure 1: Normal operation
Please note that the status of the pin OUT is dependent whether the chip is operated with or without external driver transistor. In the
subsequent diagrams, the version without external driver transistor is shown only.
0
IN
0
OUT
0
SHORT
V
DD
V
SENS
th sens
t
t
ext
del
HIGH-Z
HIGH-Z
STATUS
epc701
STATUS
epc703
t
LED
Figure 2: Short circuit detection
Note: The parameter text used in this paper is described in Figure 7.
Over-current Sequence
A short on the load side will lead to an over-current through OUT. If an over-current stays longer than the time tdel and text, OUT is turned off as
shown in the figure below. At the same time STATUS changes its state to indicate an over-current situation to an external controller. STATUS
can also be used to drive directly an indicator LED due to its 10mA driving capability. epc701 delivers a constant on-signal, whereas epc703
has a flashing output.
© 2011 ESPROS Photonics Corporation
Characteristics subject to change without notice
4
Datasheet epc701_703 - V2.2
www.espros.ch
EPC [ ESPROS PHOTONICS CORP ]
