MAX44006 datasheet(21/26 Pages) MAXIM

21 / 26 page

Maxim Integrated

MAX44006/MAX44008

RGB Color, Infrared, and Temperature Sensors

Table 14. Slave Address

dition occurs (e.g., when ambient lux readings exceed

threshold limits for a period greater than that set by

the Persist Timer register). The interrupt status bit is

cleared automatically if register 0x00 is read or if the

interrupts are disabled.

A PWRON interrupt bit is set to alert the master of a

chip-reset operation in case of a power-supply glitch,

as can happen in instruments during vibration or power

fluctuations.

It is recommended to utilize the INT pin on the devices to

alert the master to read measurements from the devices.

This eliminates the need for the microcontroller (I2C mas-

ter) to continually poll the devices for information. Due to

the use of pullup resistors on the I2C bus, minimizing I2C

bus activity can reduce power consumption substantial-

ly. In addition, this frees up the microcontroller resources

to service other background processes to improve the

devices’ performance. The wide variety of smarts avail-

able on the chip, such as the ability to set the threshold

levels and to count persist timer limits, allow the part to

operate in an autonomous mode most of the time.

Typical Operating Sequence

The typical operating sequence for the master to com-

municate to the devices is shown below:

1) Setup:

a) Read the Interrupt Status register (0x00) to confirm

only the PWRON bit is set (usually at power-up

only). This also clears the hardware interrupt.

b) Set Threshold and Persist Timer registers for ambi-

ent measurements.

c) Write 0x00 to Ambient Configuration register (reg-

ister 0x02) to set the AMB sensor in the most

sensitive gain setting, and the AMB ADCs in 14-bit

modes of operation.

d) Write 0x21 to the Main Configuration register (reg-

ister 0x01) to set the part in CLEAR + TEMP + RGB

+ IR mode and to enable AMB interrupt.

e) (Optional: Set new CLEAR, RGB, and infrared

channel gains if necessary and set TRIM bit in

2) Wait for interrupt.

3) On interrupt:

a) Read the Interrupt Status register (0x00) to confirm

the IC to be the source of interrupt. This should

clear the hardware interrupt on the part, if set.

b) If an AMB interrupt has occurred, read AMB reg-

isters (register 0x04–0x0D) and take appropriate

action (e.g., sets new backlight strength/change

display gamma). Set new AMB thresholds, if nec-

essary.

c) Return to Step 2.

I2C Serial Interface

The devices feature an I2C /SMBusK-compatible, 2-wire

serial interface consisting of a serial data line (SDA)

and a serial clock line (SCL). SDA and SCL facilitate

communication between the devices and the master

at clock rates up to 400kHz. Figure 3 shows the 2-wire

interface timing diagram. The master generates SCL

and initiates data transfer on the bus. A master device

writes data to the devices by transmitting the proper

slave address followed by the register address and then

the data word. Each transmit sequence is framed by

a START (S) or Repeated START (Sr) condition and a

STOP (P) condition. Each word transmitted to the devices

is 8 bits long and is followed by an acknowledge clock

pulse. A master reading data from the IC transmits the

proper slave address followed by a series of nine SCL

SLAVE ADDRESS FOR WRITING

SLAVE ADDRESS FOR READING

MAX44006

GND

1000 1010

1000 1011

VDD

1000 1000

1000 1001

MAX44008

GND

1000 0010

1000 0011

VDD

1000 0000

1000 0001

MAX44006 Datasheet(PDF) 21 Page - Maxim Integrated Products

MAX44006 Datasheet(HTML) 21 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Datasheet Download

Link URL