ISL29011 Datasheet, PDF (5/15 Pages) Intersil Corporation – Digital Ambient Light Sensor and Proximity Sensor with Interrupt Function

ISL29011
Electrical Specifications V_{SUP(VDDD,VDDA)} = 3V, T_A = +25°C, R_EXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless otherwise
specified. (Continued)
PARAMETER
DESCRIPTION
CONDITION
MIN TYP MAX UNIT
I_SDA, I_INT SDA and INT Current Sinking Capability
I_IRDR1
IRDR Source Current
I_IRDR2
IRDR Source Current
I_IRDR3
IRDR Source Current
I_IRDR4
IRDR Source Current
V_IRLED
Voltage Head Room of IRDR Pin
t_r
Rise Time for IRDR Source Current
t_f
Fall Time for IRDR Source Current
f_IRLED1
IR LED Modulation Frequency
f_IRLED2
IR LED Modulation Frequency
I_{SUP (IRLED1)} Supply Current of Proximity Sensing
I_{SUP (IRLED2)} Supply Current of Proximity Sensing
Duty Cycle Duty Cycle of IR LED Modulation
IS<1:0> = 0 (Note 5)
IS<1:0> = 1 (Note 5)
15Ω at IRDR pin
IS<1:0> = 2 (Note 5)
IS<1:0> = 3 (Note 5)
R_LOAD = 15Ω at IRDR pin, 20% to 80%
R_LOAD = 15Ω at IRDR pin, 80% to 20%
Freq = 0 (Note 5)
Freq = 1 (Note 5)
IS<1:0> = 0, Freq = 0 (Note 5)
IS<1:0> = 0, Freq = 1 (Note 5)
4
5
mA
100
mA
44
50
58 mA
25
mA
12.5
mA
V_DD - 0.6
V
35
ns
10
ns
DC
kHz
360
kHz
101
mA
51
mA
50
%
PROX-IR Differential ADC Output of IR and Proximity IR and proximity sensing with Range 2 and Scheme 0;
1.0
%
PROX
Sensing With Object Far Away to Provide 15Ω @ IRDR pin, IS<1:0> = 0, Freq = 0; E = 210 lux,
No Reflection
Sunlight.
NOTES:
2. V_SUP is the common voltage to V_DDD and V_DDA.
3. 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.
4. 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.
5. See “Register Set” on page 7.
Principles of Operation
Photodiodes and ADC
The ISL29011 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. See “Integration and
Conversion Time” on page 9.
The built-in ADC offers user flexibility in integration time or
conversion time. Integration time is determined by an internal
oscillator (f_OSC), and the n-bit (n = 4, 8, 12,16) counter inside
the ADC. 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 ISL29011 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 ISL29011 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 ISL29011 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 ISL29011: 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
programmable continuous proximity sensing. These six
modes can be programmed in series to fulfill the application
5
FN6467.2
May 14, 2009