SFH7773 datasheet(8/23 Pages) OSRAM

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1. Activate Ambient Light Sensor

2. Activate Proximity Sensor

3. Wait

4. Read Out PS Data

5.1 Read Out ALS Data (LSB)

5.2 Read Out ALS Data (MSB)

SFH7773 Address

(0x38)

W A

I_LED Register

(0x82)

Set LED Current to

200mA (0x1E)

A P

SFH7773 Address

(0x38)

W A

PS Control

Activate Free Running

Mode (0x03)

A P

SFH7773 Address

(0x38)

W A

ALS Control

Activate Free Running

Mode (0x03)

A P

SFH7773 Address

(0x38)

W A

PS Data Register

(0x8F)

A P

SFH7773 Address

(0x38)

R A

PS Data

SFH7773 Address

(0x38)

W A

ALS Data Register

LSB - (0x8C)

A P

SFH7773 Address

(0x38)

R A

ALS Data (LSB)

SFH7773 Address

(0x38)

W A

ALS Data Register

MSB - (0x8D)

A P

SFH7773 Address

(0x38)

R A

ALS Data (MSB)

Communication from Master to SFH 7773

Communication from SFH 7773 to Master

W: Master Writes

R: Master Reads

A: Acknowledge

NA: Not Acknowledge

S: Start Condition

P: Stop Condition

Fig. 14: I

2C-bus communication for the example described below.

The built-in I2C-bus interface is compatible

with all common I2C-bus modes (see Tab.

3). The logic voltage (VIO) of the SFH 7773

ranges from 1.6 V – 2.0 V (according to I2C-

bus specification [2]).

8.2 I²C - Bus Communication

By embedding the SFH 7773 in an I²C-bus

network and after applying VDD = 2.5 V, the

communication can start as follows (Fig. 14

illustrates this I²C-bus conversation):

1. Activation of the ALS:

The default mode of the sensor is STAND-

BY and the SFH 7773 needs to be activated

by the master (e.g. microcontroller).

Each I²C bus communication begins with a

start command “S” of the Master (SDA line

is changing from “1” to “0” during SCL line

stays “1”) followed by the address of the

slave (SFH 7773 address is 0x38). After the

7bit slave address the read (1) and write (0)

R/W bit of the master will follow. The R/W bit

controls

the

communication

direction

between the master and the addressed

slave. The slave is responding the proper

communication

with

acknowledge

command.

Acknowledge

“A”

(or

not

acknowledge “NA”) is performed from the

receiver by pulling the SDA line down (or

leave in “1” state).

For the activation of the sensor the master

needs to write an activation command

(0x03)

into

the

corresponding

control

December 12, 2011

page 8 of 23

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