SFH 7770

2011-09-16

2

Application diagram and basic informations

• The inductivity of the wire from the LED pin (1,2 or 3) to the cathode of the LED needs to be

<20nH at If=200mA (e.g. max 2 – 3cm length of a wire). The cable length may be increased for

lower currents inversely proportional to forward current: cable length

1/forward current (e.g. max 8

- 12cm at If=50mA).

• Proposed size for the pull-up resistor is 560 Ohm

• Short evaluation program

Adress

Command

Action

0x80

Write 03

Ambient Light Sensor in FREE-RUNNING mode

0x81

Write 03

Proximity Sensor in FREE-RUNNING mode

Wait 110 ms

0x8C

Read data

read LSByte data from ambient light measurement

0x8D

Read data

read MSByte data from ambient light measurement

0x8F

Read data

read data from proximity measurement LED 1

LED 1

LED 2

LED 3

SFH 7770

MCU

100nF

9

8

3

2

1

4

7

6

10

5

SDA

SCL

nc

INT

GND_LED

GND

10 μF