ISL29015IROZ-EVALZ Intersil, ISL29015IROZ-EVALZ Datasheet - Page 8

• Manufacturer Part Number: ISL29015IROZ-EVALZ
• Description: EVALUATION BOARD FOR ISL29015
• Manufacturer: Intersil

Specifications of ISL29015IROZ-EVALZ

• Sensor Type: Light, Digital Output
• Sensing Range: 65535Lux
• Interface: I²C, SMBus
• Sensitivity: 540nm
• Voltage - Supply: 2.25 V ~ 3.3 V
• Embedded: No
• Utilized Ic / Part: ISL29015
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Here, E
changes with the spectrum of background IR noise like
sunlight and incandescent light. The β also changes with the
ADC’s range and resolution selections.
ADC Output in Proximity Sensing
In the proximity sensing, the ADC output codes, DATA, are
directly proportional to the total IR intensity from the
background IR noise and from the IR LED driven by the
ISL29015.
β and E
Equation 7. The constant γ depends on the spectrum of the
used IR LED and the ADC’s range and resolution selections.
E
and reflected by a specific objector to the ISL29015. E
depends on the current to the IR LED and the surface of the
object. E
between the object and the sensor.
If background IR noise is small, i.e., E
the ADC output directly decreases with the distance. If there
is significant background IR noise, the sequence of the
proximity sensing followed by the IR sensing can be
implemented. The differential reading of ADC outputs from
the proximity and IR sensing has no effect of background
IR noise and directly decreases with the distance between
the object and the sensor. Please refer to “Typical
Performance Curves” on page 10 for ADC output vs
distance. Figure 9 shows ISL29015 configured at 12-bit ADC
resolution, 12.5mA external LED current at 327.7KHz
modulation frequency, detects three different sensing
objects: 92% brightness paper, 18% gray card and ESD
black foam. Figure 10 shows ISL29015 configured at 12-bit
ADC resolution, programmed external LED at 327.7KHz
modulation frequency, detects the same sensing object: 18%
gray card under four different external LED current: 12.5mA,
25mA, 50mA and 100mA to compare the proximity readout
versus distance.
Current Consumption Estimation
The low power operation is achieved through sequential
readout in the serial fashion, as shown in Figure 3, the
device requires three different phases in serial during the
entire detection cycle to do ambient light sensing, infrared
sensing and proximity sensing. The external IR LED will only
be turned on during the proximity sensing phase under user
program controlled current at modulated frequency depends
on user selections. Figure 3 also shows the current
consumption during each ALS, IR sensing and Proximity
sensing phase. For example, at 8-bit ADC resolution the
integration time is 0.4ms. If user programed 50mA current to
supply external IR LED at 327.7kHz modulated frequency,
DATA
DATA
LED
is the IR intensity which is emitted from the IR LED
IR
PROX
IR
IR
LED
=
is the received IR intensity. The constant β
in Equation 8 have the same meanings as in
β
=
×
decreases with the square of the distance
E
β
IR
×
E
IR
+
γ
×
E
LED
8
IR
can be neglected,
(EQ. 7)
(EQ. 8)
LED
ISL29015
during the entire operation cycle that includes ALS, IR
sensing and Proximity sensing three different serial phases,
the detection occurs once every 30ms, the average current
consumption including external IR LED drive current can be
calculated from Equation 9:
If at a 12-bit ADC resolution where the integration time for
each serial phase becomes 7ms and the total detection time
becomes 100ms, the average current can be calculated from
Equation 10:
Suggested PCB Footprint
It is important that the users check the “Surface Mount
Assembly Guidelines for Optical Dual FlatPack No Lead
(ODFN) Package” before starting ODFN product board
mounting.
http://www.intersil.com/data/tb/tb477.pdf
Layout Considerations
The ISL29015 is relatively insensitive to layout. Like other
I
even in significantly noisy environments. There are only a
few considerations that will ensure best performance.
Route the supply and I
sources of noise. Use two power-supply decoupling
capacitors, 1µF and 0.1µF, placed close to the device.
Typical Circuit
A typical application for the ISL29015 is shown in Figure 4.
The ISL29015’s I
1000100. The device can be tied onto a system’s I
together with other I
Soldering Considerations
Convection heating is recommended for reflow soldering;
direct-infrared heating is not recommended. The plastic
ODFN package does not require a custom reflow soldering
profile, and is qualified to +260°C. A standard reflow
soldering profile with a +260°C maximum is recommended.
[
[
2
(
(
0.05mA
0.05mA
C devices, it is intended to provide excellent performance
+
+
0.05mA
0.05mA
+
+
2
1mA
1mA
C address is internally hardwired as
2
C compliant devices.
+
+
2
(50mA ∗ 50%)) ∗ 0.4ms
(50mA ∗ 50%)) ∗
C traces as far as possible from all
7
ms
)
]/100ms = 1.83mA
)
]/30ms = 0.35mA
October 31, 2008
2
C bus
(EQ. 10)
FN6522.0
(EQ. 9)