MAX44009EDT+T Maxim Integrated Products, MAX44009EDT+T Datasheet - Page 12

• Manufacturer Part Number: MAX44009EDT+T
• Description: Optical Sensors - Industrial Digital Ambient Ligh Ambient Light Sensor
• Manufacturer: Maxim Integrated Products

Specifications of MAX44009EDT+T

• Operating Supply Voltage: 1.7 V to 3.6 V
• Maximum Power Dissipation: 953 mW
• Package / Case: TDFN-6
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 0.65 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Industry’s Lowest-Power
Ambient Light Sensor with ADC
The count is multiplied by 0.045, which is the LSB.
Because of the logarithmic nature of autoranging cir-
cuitry implemented on the IC, resolution of ambient lux
readings scale with the absolute measurement. Table 8
lists the lux resolution and the lux ranges obtained from
the IC.
Interrupt is enabled by setting bit 0 of register 0x01 to
1 (see Table 1). INT, an open-drain output, pulls low
when an interrupt condition occurs (lux readings that
exceed threshold limits for a period greater than that set
by the Time register). The interrupt status bit is cleared
automatically if register 0x00 is read or if the interrupt is
disabled (INTE = 0).
The IC’s interrupt circuit requires the upper and lower
limit thresholds to be in a specific format to be properly
interpreted. The upper and lower limits, from registers
0x05 and 0x06 must match the lux high-byte format. This
consists of the 4 bits of the exponent and the 4 most sig-
nificant bits of the mantissa (E3 E2 E1 E0 M7 M6 M5 M4).
In this case, there is the following formula:
Lower lux threshold = (2
The exponent is a 4-bit number ranging from 0000 to
1110 (zero to 14).
Table_8._Lux_per_LSB_in_Automatic_Mode
12
LUx_(MIN)
11,796.5
23,593.0
47,185.9
94,371.8
1474.6
2949.1
5898.2
184.3
368.6
737.3
11.5
23.0
46.1
92.2
0
Threshold Register Data Format
(exponent)
LUx_(MAx)
188,006.4
11,796.5
23,593.0
47,185.9
94,371.8
1474.6
2949.1
5898.2
184.3
368.6
737.3
11.5
23.0
46.1
92.2
Interrupt Settings
x mantissa) x 0.045
AUTOMATIC_MODE
LUx_PER_LSB_IN_
184.32
368.64
737.28
0.045
11.52
23.04
46.08
92.16
0.09
0.18
0.36
0.72
1.44
2.88
5.76
The mantissa is an 8-bit number ranging from 0000 0000
to 1111 0000 (zero to 240).
Upper lux threshold = (2
The exponent is a 4-bit number ranging from 0000 to
1110 (zero to 14).
The mantissa is an 8-bit number ranging from 0000 1111
to 1111 1111 (15 to 255).
In the auto range mode (MANUAL = 0), the upper thresh-
old and lower threshold bytes must be in a format that
matches the format used in register 0x03, the lux high
byte. There are only two rules to follow:
• For very low lux levels (light levels below 11.5 lux),
• For all other conditions (light levels above 11.5 lux)
In manual mode (MANUAL = 1), Table 9 gives the range
of exponent (E3 E2 E1 E0) that can be used for each
TIM[2:0] and CDR bit setting.
set the exponent to zero, the code is merely: 0000
MMMM where the 4 zeroes are the exponent, and the
MMMM represent the 4 most significant bits of the
mantissa.
where the exponent is not zero, the format is: EEEE
1MMM. Notice that bit M7 (most significant bit) must
always be a 1. The other bits do not matter. EEEE is
limited to a maximum value of 1110. The maximum
usable setting is a code of 1110 1111.
COUNTS_(MIN)
1,048,576
2,097,152
131,072
262,144
524,288
16,384
32,768
65,536
1024
2048
4096
8192
256
512
0
(exponent)
x mantissa) x 0.045
COUNTS_(MAx)
1,048,576
2,097,152
4,177,920
131,072
262,144
524,288
16,384
32,768
65,536
1024
2048
4096
8192
256
512