Power supply Positive power supply for regulator and positive terminal of the 2-wire interface.
Power supply Negative power supply pin.
Analog Input
Digital Input
Analog Out
Digital Out
Photo diode input.
SPI Interface: Chip Select. Active low, with pull up
Amplified and filtered signal of the photo diode (push-pull) or
light reserve output (open drain) with 50 % threshold voltage above the threshold of the
OUT output.
6
7
8
9
10
n/a
n/a
n/a
n/a
n/a
n/a
1
15
14
12
10
3
5
8
11
13
16
Digital Output SPI Interface: Serial out
Digital Input
Digital Input
SPI Interface: Serial input
SPI Interface: Shift Clock
Power supply Positive power supply for analog and digital. If the the device is supplied by V
DDR
, a
Decoupling
power supply filter capacitor is connected to this pin.
Analog Out
1.8 V regulator output. Do not use this pin, except for a decoupling capacitor.
Not connected. Connect this pin with VSS.
Not connected. Connect this pin with VSS.
Not connected. Connect this pin with VSS.
Not connected. Connect this pin with VSS.
Not connected. Connect this pin with VSS.
Not connected. Connect this pin with VSS.
PIN Connections QFN16-VEED-
1VN4
File: Unbenannt
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
The epc100 device can be operated in two different modes:
a) Photo Current Receivers
It detects current pulses of the photo diode generated by light pulses and transmits the information using the 2-wire bus to a central con -
troller, i.e. a micro controller. The devices operating as this photo current receivers are designated in the schematic diagram above as R
1
to
R
n
.
b) 2-Wire Bus Interface of the Central Controller
It manages the 2-wire bus traffic between the micro controller and the individual photo current receivers. The device operating as the inter-
face unit is designated as I
F
.
From the point of view of the micro controller, the whole system looks like a single device with several addressable photo diodes. The micro
controller activates one photo diode and fetches the results after a predefined time. Each sensor device has two different operation modes: A
18.05.2011
LST
standby and an operating mode. During the standby mode the power consumption is reduced and the DC current generated in the photo di -
AN epc100 light curtain receiver
Page 1
ode is shorted. During the operation mode, the micro controller addresses one device after the other and fetches the result. The result con -
File:
tains the information whether a light pulse has been received in a predefined receive window or not. It also contains the time point when the
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
.
light pulse has been received in respect to the receive window.
The receiver channel detects current pulses which are generated by light pulses in the photo diodes. The detection circuitry has two trigger
levels, hereinafter called thresholds, which form a digital signal from the analog current change. The lower threshold is called OUTN (normal)
whereas the upper level is called OUTH (high). Both trigger thresholds can be configured individually per chip. Please refer to Figure 2 and to
the Reference Manual epc10x which contains the configuration information.