epc700/epc702
Functional Description
Normal Operation
During typical operation the OUT follows the IN as shown in Figure 1. 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 t
ON
and t
OFF
for the rising and the falling edge
respectively.
IN
0
V
OUT (without
HIGH-Z
external Transistor)
OUT (with
V
external Transistor)
Sat
t
on
Sat
VDD
t
off
SHORT
0
V
th sens
SENS
0
STATUS
HIGH-Z
epc700
STATUS
HIGH-Z
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 with external driver transistor is shown only.
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 t
del
and t
ext
, 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. epc700 delivers a constant on-signal, whereas epc702
has a flashing output.
IN
0
OUT
0
0
V
th sens
SHORT
SENS
0
t
ext
t
del
STATUS
epc700
HIGH-Z
t
LED
t
LED
STATUS
HIGH-Z
epc702
t
LED
Figure 2: Short circuit detection
Note: The parameter t
ext
used in this paper is described in Figure 7.
Timing diagram operation mode
epc700
File:
LST
05.01.2011
Page 1
This document is confidential and protected by law and international trades. It must not be shown to any third party nor be copied in any form without our written permission
.
© 2011 ESPROS Photonics Corporation
Characteristics subject to change without notice
4
Datasheet epc700_702 - V2.2
www.espros.ch
EPC [ ESPROS PHOTONICS CORP ]
