epc101

Overview Functional Description

Light Curtain – Transmitter

Figure 1 shows a typical schematic circuit of a light curtain emitter edge. A microcontroller manages the transmitters in the edge via an inter -

face chip (epc100) to the 2-wire power and communication bus. Since the LEDs draw a very high peak current when enabled, huge noise on

he 2-wire bus would interfere with the communication protocol on the bus. Thus, the LEDs are connected to a separate 2-wire power bus.

Part Name

Part No.

Designed

Approved

Scale

Page

<Text>

M 1:1

<Date>

DIN A3

<Partname>

<x000 000>

<Text>

File: Unbenannt

26.02.2009

1

<xx>

VDD33

IF

VDD

epc100

GND

SO

SCK

SI

CS

µC

GND

VDD µC

VDD

+ I

LED

- I

LED

PD

VDD33

VDD

epc101

GND

LED

T

n

VDD18

R

LED

C1

C2

PD

VDD33

VDD

epc101

GND

LED

T

2

VDD18

R

LED

C1

C2

PD

VDD33

VDD

epc101

GND

LED

T

1

VDD18

R

LED

C1

C2

Figure 1: Light curtain transmitter with up to 300mA pulse current through the LED

The feedback LED voltage to the PD input is to allocate the physical location of the transmitter node to the unique chip ID during production.

In this mode the the LED is used as a receiver. For configuration please refer to the Reference Manual epc10x.

safety applications. If this resistor is inserted, a failure mode will be detected if more than one LED is active due to a short circuit or a failure in

the epc101. It is also possible to have a common voltage supply and to control the LED current by a series resistor.

In order to allow a stable operation of the transmitter nodes, two voltage supply decoupling capacitors are needed: C1 should be of 100nF and

C2 4.7nF, both ceramic types.

For long range applications, a LED current of up to 1A is needed. Such a high pulse current can be achieved by using a darlington stage ac -

40.

Part Name

Part No.

Designed

Approved

Scale

Page

<Text>

M 1:1

<Date>

DIN A3

<Partname>

<x000 000>

<Text>

File: Unbenannt

26.02.2009

1

<xx>

VDD33

IF

VDD

epc100

GND

SO

SCK

SI

CS

µC

GND

VDD µC

VDD

+ I

LED

- I

LED

VDD18

PD

VDD33

VDD

epc101

GND

LED

T

n

R

LED

R

T1

T2

C1

C2

VDD18

PD

VDD33

VDD

epc101

GND

LED

T

n

R

LED

R

T1

T2

C1

C2

VDD18

PD

VDD33

VDD

epc101

GND

LED

T

n

R

LED

R

T1

T2

C1

C2

VDD18

PD

VDD33

VDD

epc101

GND

LED

T

1

R

LED

R

T1

T2

C1

C2

VDD18

PD

VDD33

VDD

epc101

GND

LED

T

n

R

LED

R

T1

T2

C1

C2

VDD18

PD

VDD33

VDD

epc101

GND

LED

T

2

R

LED

R

T1

T2

C1

C2

Figure 2: Light curtain transmitter with more then 300mA pulse current through the LED

© 2011 ESPROS Photonics Corporation

Characteristics subject to change without notice

4

Datasheet epc101 - V2.1

www.espros.ch