ISL29018IROZ-T7 Intersil, ISL29018IROZ-T7 Datasheet - Page 8

• Manufacturer Part Number: ISL29018IROZ-T7
• Description: IC SENSOR AMB LGT-DTGL I2C 8ODFN
• Manufacturer: Intersil

Specifications of ISL29018IROZ-T7

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Command Register II 01(hex)
The second command register has the following functions:
.
1. Proximity Sensing Scheme: Bit 7. This bit programs the
2. Modulation Frequency: Bits 6. This bit sets the IR LED
3. Amplitude of IR driver current: Bits 5 and 4. This device
4. Resolution: Bits 3 and 2. Bits 3 and 2 determine the ADC’s
BITS 5 TO 4
BITS 3 TO 2
TABLE 7. CURRENT SOURCE CAPABILITY AT IRDR PIN
function of the proximity detection. Logic 0 of this bit,
Scheme 0, makes full n (4, 8, 12, 16) bits (unsigned)
proximity detection. The range of Scheme 0 proximity
count is from 0 to 2
n-1 (3, 7, 11, 15) bits (2’s complementary)
proximity_less_ambient detection. The range of Scheme
1 proximity count is from -2
0 has wider dynamic range, Scheme 1 proximity
detection is less affected by the ambient IR noise
variation.
driver’s modulation frequency.
provides current source to drive an external IR LED. The
drive capability can be programmed through Bits 5 and 4.
For example, the device sources 12.5mA out of the IRDR
pin if Bits 5 and 4 are 0.
resolution and the number of clock cycles per conversion
in Internal Timing Mode. Changing the number of clock
cycles does more than just change the resolution of the
device. It also changes the integration time, which is the
period the device’s analog-to-digital (A/D) converter
samples the photodiode current signal for a measurement.
BITS 6
00
01
10
11
BIT 7
00
01
10
11
0
1
0
1
TABLE 5. PROXIMITY SENSING SCHEME
TABLE 6. MODULATION FREQUENCY
12.5mA IR LED driver
25mA IR LED driver
50mA IR LED driver
100mA IR LED driver
TABLE 8. RESOLUTION/WIDTH
2
2
2
2
NUMBER OF CLOCK CYCLES
16
12
8
4
Sensing IR from LED and ambient
Sensing IR from LED with ambient IR rejection
= 256
= 16
= 65,536
= 4,096
n
IRDR PIN SOURCE CURRENT
. Logic 1 of this bit, Scheme 1, makes
MODULATION FREQUENCY
8
(n-1)
OPERATION
to 2
(kHz)
360
DC
(n-1)
. While Scheme
n-BIT ADC
16
12
8
4
ISL29018
Data Registers (02 hex and 03 hex)
The device has two 8-bit read-only registers to hold the data
from LSB to MSB for ADC. The most significant bit (MSB) is
accessed at 03 hex, and the least significant bit (LSB) is
accessed at 02 hex. For 16-bit resolution, the data is from
D0 to D15; for 12-bit resolution, the data is from D0 to D11;
for 8-bit resolution, the data is from D0 to D7. The registers
are refreshed after every conversion cycle.
Interrupt Registers (04, 05, 06 and 07 hex)
Registers 04 and 05 hex set the low (LO) threshold for the
interrupt pin and the interrupt flag. 04 hex is the LSB and 05
hex is the MSB. By default, the Interrupt threshold LO is 00
hex for both LSB and MSB.
Registers 06 and 07 hex set the high (HI) threshold for the
interrupt pin and the interrupt flag. 06 hex is the LSB and 07
hex is the MSB. By default, the Interrupt threshold HI is FF
hex for both LSB and MSB.
Test Register (08 hex)
The part functions in normal operation mode when Register
8 is set to 0x00.
Calculating Lux
The ISL29018’s ADC output codes, DATA, are directly
proportional to lux in the ambient light sensing as shown in
Equation 1.
Here, E
determined by the Full Scale Range and the ADC’s
maximum output counts. The constant is independent on the
light sources (fluorescent, incandescent and sunlight)
because of the light sources’ IR component is removed
during the light signal process. The constant can also be
E
5. Range: Bits 1 and 0. The Full Scale Range (FSR) can be
ADDRESS
cal
BITS
1:0
00
01
10
11
adjusted via I
possible values of FSR for the 499kΩ R
(hex)
02
03
=
α
cal
×
k
1
2
3
4
DATA
is the calculated lux reading. The constant α is
D0 is LSB for 4, 8, 12 or 16-bit resolution, D3 is MSB
for 4-bit resolution, D7 is MSB for 8-bit resolution
D15 is MSB for 16-bit resolution, D11 is MSB for
12-bit resolution
RANGE(k)
Range1
Range2
Range3
Range4
TABLE 10. DATA REGISTERS
TABLE 9. RANGE/FSR LUX
2
C using Bits 1 and 0. Table 9 lists the
ALS SENSING
FSR (LUX) @
CONTENTS
16,000
64,000
1,000
4,000
EXT
Refer to page 4
Refer to page 4
Refer to page 4
Refer to page 4
FSR @ IR
SENSING
February 11, 2010
resistor.
FN6619.1
(EQ. 1)