epc700/epc702

Current Peak at OUT

A short current peak when OUT is turned on, typically generated by a capacitive load, could trigger the short-circuit protection logic. However,

Make sure that the energy drawn by such a current peak does not destroy the internal/external output transistor.

Over-current Reset Sequence

to turn on OUT again. If the short circuit is still present, OUT is immediately turned off again. This sequence continues until the short circuit is

removed or IN goes to LOW or power is turned off. This mode is called self-healing since the device tries to self-heal the short circuit end to

switch back into normal operation.

As a consequence in the case of a permanent over-current , short current peaks are issued into the load, respectively short.

If one wants to reduce the waiting time in case of a short circuit situation, it can be done by simply taking IN to a low state and then to high

again. Please refer to the timing diagram in Figure 5. However, make sure that the maximum power dissipation of the chip or the external

switching transistor will never be exceeded above the allowed maximum.

© 2011 ESPROS Photonics Corporation

Characteristics subject to change without notice

5

Datasheet epc700_702 - V2.2

www.espros.ch

Figure 3: Short over-current pulse, i.e., by switching a capacitive load

Timing diagram not enough

overcurrent epc700

LST

V

th sens

<t

del

t

ext

IN

OUT

STATUS

SENS

HIGH-Z

01.08.2010

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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

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Figure 4: Over-current reset sequence

Timing diagram normal overcurrent

release epc700

LST

V

th sens

t

del

t

ext

IN

OUT

STATUS

epc700

SHORT

SENS

t

minOFF

HIGH-Z

05.01.2011

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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

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STATUS

epc702

0

0

0

0

t

LED

HIGH-Z

Figure 5: Over-current status reset

Timing diagram reset overcurren

epc700

Lukas Steinemann

V

th sens

t

del

t

ext

IN

OUT

STATUS

SHORT

SENS

<t

minOFF

HIGH-Z

01.08.2010

Page 1

...

File:

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

.