epc110

Applications

Long range light barrier application (refer also to datasheet epc111)

Figure 18 shows the epc110 as an example in a long range light barrier application with minimal part count. The LED flashes according to the

description of the previous chapter. Light of the LED is passing either direct, reflecting from a reflecting object or a retro reflector to the photo

diode PD. If the received light fulfills the criteria according to the description in the previous chapter, the output signals OUTN and OUTH are

set.

LED Driver:

The output LED of the epc110 to drive the LED driver circuit is a current source capable to drive typically 1mA. For a high performance long

range light barrier (>8m), an LED peak current of up to 1.5A is needed. To generate such a high LED current, an external driver circuit is

necessary. The circuitry in Figure 18 is a simple implementation of such a driver circuit. The darlington circuit with T2 and T3 and R2 and R3

does the job. In order to avoid interference on the supply voltage, the supply is isolated (filtered) with R1 and C1. The high peak LED pulse

current is delivered by the capacitor C1, which itself is charged by R1. Make sure, that there is no coupling of the high LED current to the

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OUTH

LED

OUTN

PD

VDD33

VDD

epc110

GND

VDD18

R3

1R2

C1

47μF

Low ESR

GND

+3.3V

VDD

LED

= +24V

OUTH

OUTN

PD

epc300

T2

BC846

R2

1k

R5

3k6

R4

10k

IR LED

TSML1000

R1

100R

C3 100nF

C2 1μF

C5 4.7nF

C4 100nF

R6

12k

R8

10k

R7

4k7

T1

BC846

T3

BCP56

Marked conductors must be short and low ohmic

C2

The epc111 device with its very sensitive input PD needs a well decoupled power supply

Figure 18: Long range light barrier application with minimal part count

Notice:

The schematic is for illustrating the basic circuit idea only. For the real built up the designer has to take all other additional influence factors in

consideration too e.g. design rules, power rating, heat dissipation, ...

ROM RAM

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

0

16

1

1

0

1

1

0

0

0

0

0

0

0

0

1

1

FUSEBIT

1

17

0

1

1

1

1

0

0

0

0

0

1

0

0

0

0

FUSEBIT

2

18

0

0

0

0

1

0

1

0

1

0

1

1

0

1

1

FUSEBIT

3

19

don't use

FUSEBIT

4

20

don't use

FUSEBIT

Trimming

5

21

don't use

FUSEBIT

6

22

don't use

FUSEBIT

7

23

don't use

FUSEBIT Device Address

8

24

Lot no. LSB

FUSEBIT

Chip ID

9

25

Lot no. MSB

FUSEBIT

10

26

Chip ID

FUSEBIT

11

27

Factory use only

FUSEBIT

12

28

Revision no.

FUSEBIT

13

29

no function

FUSEBIT

14

30

no function

FUSEBIT

15

31

no function

FUSEBIT

Application

parameters

Figure 19: Corresponding memory map epc110 “Long range”

Parameter settings can be done by writing complete 16 bit registers only.

© 2011 ESPROS Photonics Corporation

Characteristics subject to change without notice

21

Datasheet epc110 - V2.1

www.espros.ch