ISL29015 View Datasheet(PDF) - Intersil
Part Name
Description
View to exact match
ISL29015 Datasheet PDF : 13 Pages
| |||
ISL29015
Electrical Specifications VDD = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless
otherwise specified. (Continued)
PARAMETER
DESCRIPTION
CONDITION
MIN TYP MAX UNIT
ISDA
IIRDR1
IIRDR2
IIRDR3
IIRDR4
VIRLED
tr
tf
fIRLED1
fIRLED2
IDD (IRLED1)
IDD (IRLED2)
Duty Cycle
SDA Current Sinking Capability
IRDR Source Current
IS<1:0> = 0 (Note 4)
IRDR Source Current
IRDR Source Current
IS<1:0> = 1 (Note 4)
1.5V at IRDR pin
IS<1:0> = 2 (Note 4)
IRDR Source Current
IS<1:0> = 3 (Note 4)
Voltage Head Room of IRDR Pin
Rise Time for IRDR Source Current
Fall Time for IRDR Source Current
IR LED Modulation Frequency
RLOAD = 15Ω at IRDR pin, 20% to 80%
RLOAD = 15Ω at IRDR pin, 80% to 20%
Freq<1:0> = 0 (Note 4)
IR LED Modulation Frequency
Freq<1:0> = 3 (Note 4)
Supply Current of Proximity Sensing IS<1:0> = 0, Freq<1:0> = 0 (Note 4)
Supply Current of Proximity Sensing IS<1:0> = 0, Freq<1:0> = 3 (Note 4)
Duty Cycle of IR LED Modulation
4
5
mA
100
mA
44
50
56
mA
25
mA
12.5
mA
VDD - 0.6
V
35
ns
10
ns
DC
kHz
360
kHz
101
mA
51
mA
50
%
PROX-IR
Differential ADC Output of IR and IR and proximity sensing with Range 2; 1.5V @ IRDR
2.0
%
PROX
Proximity Sensing With Object Far pin, IS<1:0> = 0, Freq<1:0> = 0; E = 210 lux, Sunlight.
Away to Provide No Reflection
NOTES:
2. 550nm green LED is used in production test. The 550nm LED irradiance is calibrated to produce the same DATA count against an illuminance
level of 300 lux fluorescent light.
3. 850nm infrared LED is used in production test. The 850nm LED irradiance is calibrated to produce the same DATA_IR count against an
illuminance level of 210 lux sunlight at sea level.
4. See “Register Set” on page 6.
Principles of Operation
Photodiodes and ADC
The ISL29015 contains two photodiode arrays which convert
light into current. The spectral response for ambient light
sensing and IR sensing is shown in Figure 6 in the performance
curves section. After light is converted to current during the light
signal process, the current output is converted to digital by a
built-in 16-bit Analog-to-Digital Converter (ADC). An I2C
command reads the ambient light or IR intensity in counts.
The converter is a charge-balancing integrating type 16-bit
ADC. The chosen method for conversion is best for converting
small current signals in the presence of an AC periodic noise. A
100ms integration time, for instance, highly rejects 50Hz and
60Hz power line noise simultaneously.
The built-in ADC offers user flexibility in integration time or
conversion time. There are two timing modes: Internal Timing
Mode and External Timing Mode. In Internal Timing Mode,
integration time is determined by an internal oscillator (fOSC),
and the n-bit (n = 4, 8, 12,16) counter inside the ADC. In
External Timing Mode, integration time is determined by the
time between two consecutive I2C External Timing Mode
commands. See “Integration and Conversion Time” on page 7.
A good balancing act of integration time and resolution
depending on the application is required for optimal results.
The ADC has I2C programmable range select to dynamically
accommodate various lighting conditions. For very dim
conditions, the ADC can be configured at its lowest range
(Range 1) in the ambient light sensing. For very bright
conditions, the ADC can be configured at its highest range
(Range 4) in the proximity sensing.
Low-Power Operation
The ISL29015 initial operation is at the power-down mode after
a supply voltage is provided. The data registers contain the
default value of 0. When the ISL29015 receives an I2C
command to do a one-time measurement from an I2C master, it
will start ADC conversion with light or proximity sensing. It will
go to the power-down mode automatically after one conversion
is finished and keep the conversion data available for the
master to fetch anytime afterwards. The ISL29015 will
continuously do ADC conversion with light or proximity sensing
if it receives an I2C command of continuous measurement. It
will continuously update the data registers with the latest
conversion data. It will go to the power-down mode after it
receives the I2C command of power-down.
Ambient Light, IR and Proximity Sensing
There are six operational modes in ISL29015: Programmable
ALS once with auto power-down, programmable IR sensing
once with auto power-down, programmable proximity sensing
once with auto power-down; programmable continuous ALS
sensing, programmable continuous IR sensing and
4
FN6522.0
October 31, 2008
Share Link: 