ISL29030A
Principles of Operation
I 2 C Interface
The ISL29030A I 2 C interface slave address is internally hardwired
as 0b1000100.
Figure 2 shows a sample one-byte read. The I 2 C bus master
always drives the SCL (clock) line, while either the master or the
slave can drive the SDA (data) line. Every I 2 C transaction begins
with the master asserting a start condition (SDA falling while SCL
remains high). The first transmitted byte is initiated by the
master and includes seven address bits and a R/W bit. The slave
is responsible for pulling SDA low during the ACK bit after every
transmitted byte.
Each I 2 C transaction ends with the master asserting a stop
condition (SDA rising while SCL remains high).
For more information about the I 2 C standard, please consult the
Philips ? I 2 C specification documents.
Photodiodes and ADCs
The ISL29030A contains two photodiode arrays that convert
photons (light) into current. The ALS photodiodes are constructed to
mimic the human eye wavelength response curve to visible light
(see Figure 7). The ALS photodiode current output is digitized by a
12-bit ADC in 100ms. These 12 bits can be accessed by reading
from I 2 C registers 0x9 and 0xA when the ADC conversion is
completed.
The ALS converter is a charge-balancing, integrating, 12-bit ADC.
Charge-balancing is best for converting small current signals in the
presence of periodic AC noise. Integrating over 100ms highly rejects
both 50Hz and 60Hz light flicker by picking the lowest-integer
number of cycles for both 50Hz/60Hz frequencies.
The proximity sensor is an 8-bit ADC that operates in a similar
fashion. When proximity sensing is enabled, the IRDR pin drives
a user-supplied infrared LED, the emitted IR reflects off an object
(i.e., a human head) back into the ISL29030A, and a sensor
ALS CONVERSION
TIME = 100ms
(FIXED)
ALS
ACTIVE
converts the reflected IR wave to a current signal in 0.54ms. The
ADC subtracts the IR reading before and after the LED is driven
(to remove ambient IR such as sunlight) and converts this value
to a digital count stored in Register 0x8.
The ISL29030A is designed to run two conversions concurrently: a
proximity conversion, and an ALS (or IR) conversion. Please note
that because of the conversion times, the user must let the ADCs
perform one full conversion first before reading from I 2 C
Registers PROX_DATA (wait 0.54ms) or ALSIR_DT1/2 (wait
100ms). The timing between ALS and Prox conversions is
arbitrary, as shown in Figure 3. The ALS runs continuously, with
new data available every 100ms. The proximity sensor runs
continuously, with a time between conversions decided by
PROX_SLP (Register 1 Bits [6:4]).
Ambient Light and IR Sensing
The ISL29030A is set for ambient light sensing when Register bit
ALSIR_MODE = 0 and ALR_EN = 1. The light-wavelength response of
the ALS appears as shown in Figure 6. ALS measuring mode (as
opposed to IR measuring mode) is set by default.
When the part is programmed for infrared (IR) sensing
(ALSIR_MODE = 1; ALS_EN = 1), infrared light is converted into a
current and is digitized by the same ALS ADC. The result of an IR
conversion is strongly related to the amount of IR energy incident
on the sensor, but it is unitless and is referred to in digital counts.
Proximity Sensing
When proximity sensing is enabled (PROX_EN = 1), the external
IR LED is driven through the IRDR pin for 0.1ms by the built-in IR
LED driver. The amplitude of the IR LED current depends on
Register 1 bit 3: PROX_DR. If this bit is low, the load sees a fixed
110mA current pulse. If this bit is high, the load on IRDR sees a
fixed 220mA current pulse, as shown in Figure 4.
SEVERAL μs BETWEEN
CONVERSIONS
100ms
100ms
100ms
100ms
100ms
TIME
PROX
SENSOR
ACTIVE
IRDR
(CURRENT
DRIVER)
0.54ms FOR
PROX
CONVERSION
SERIES OF
CURRENT PULSES
TOTALING 0.1ms
TIME
TIME
SLEEP TIME
(PROX_SLP)
FIGURE 3. TIMING DIAGRAM FOR PROX/ALS EVENTS - NOT TO SCALE
9
FN7722.2
November 12, 2012
相关PDF资料
ISL29101IROZ-EVALZ EVALUATION BOARD FOR ISL29101
ISL29102IROZ-EVALZ EVALUATION BOARD FOR ISL29102
ISL5961EVAL2 ISL5961 TSSOPEVALUATION PLATF
ISL76683EVAL1Z BOARD EVALUATION FOR ISL76683
ISL97632IRTZ-EVALZ EVAL BOARD FOR ISL97632IRTZ
ISL97671IRZ-EVALZ BOARD EVALUATION FOR ISL97671
ISL97684IRTZEVALZ EVAL BOARD LED DRIVER
ISL97801BOOSTEVALZ EVAL BOARD FOR ISL97801
相关代理商/技术参数
ISL29030AIROZ-T7 功能描述:IC PROXIMITY SENSOR AMB LT 8ODFN RoHS:是 类别:传感器,转换器 >> 多功能 系列:* 其它有关文件:Automotive Product Guide 标准包装:2,500 系列:- 传感器类型:光线和近程 输出类型:I²C?
ISL29030IROZ-EVALZ 制造商:Intersil Corporation 功能描述: 制造商:Intersil Corporation 功能描述:ISL29030IROZ-EVALZ (PB-FREE ) EVALUATION BOARD - ROHS COMPLI - Bulk 制造商:Intersil Corporation 功能描述:ISL29030IROZ-EVALZ (PB-Free ) EVALUATION BOARD - ROHs Compli
ISL29030IROZ-T7 制造商:Intersil Corporation 功能描述:ISL29030IROZ PBFREE AUTONOMOUS LOW POWER ALS + PROXIMITY SEN - Tape and Reel 制造商:Intersil Corporation 功能描述:ISL29030IROZ PbFree Autonomous Low Power ALS + Proximity sen T/R
ISL29033IROZ-T7 功能描述:IC PHOTO DETECTOR AMBIENT 6-ODFN RoHS:是 类别:传感器,转换器 >> 光学 - 光电探测器 - 环境光传感器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 产品变化通告:Product Discontinuation 25/Jun/2012 标准包装:2,500 系列:- 带接近传感器:无 波长:- 电源电压:1.7 V ~ 2 V 电流 - 暗(标准):- 电流 - 光(典型值):- 输出类型:数字 - I²C 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UDFN 裸露焊盘 包装:带卷 (TR)
ISL29035IROZ-T7 制造商:Intersil Corporation 功能描述:ISL29035IROZ PB-FREE INTEGRATED DIGITAL LIGHT SENSOR WITH IN - Tape and Reel 制造商:Intersil Corporation 功能描述:IC PROXIMITY SENSOR AMB LT 6HODF 制造商:Intersil Corporation 功能描述:Integrated Digital Light Sensor with Interrupt. 制造商:Intersil Corporation 功能描述:IC, DIGITAL LIGHT SENSOR, ODFN-6, IC Function:Light to Digital Output Sensor, Brief Features:-, Supply Voltage Min:2.25V, Supply Voltage Max:3.63V, Operating Temperature Min:-40C, Operating Temperature Max:85C, No. of Pins:6
ISL29038IROZ-T7 制造商:Intersil Corporation 功能描述:ISL29038IROZ PBFREE AUTONOMOUS LOW POWER ALS + PROXIMITY SEN - Tape and Reel 制造商:Intersil Corporation 功能描述:IC PROXIMITY SENSOR AMB LT 8ODFN 制造商:Intersil 功能描述:Low Power ALS and Proximity Sensor
ISL29038IROZ-T7S2764 制造商:Intersil Corporation 功能描述:MOTOROLA SOLUTIONS, ISL29038IROZ-T7 W/ BARCODE LABELING, BUS - Tape and Reel
ISL29040IROMZ-EVALZ 制造商:Intersil Corporation 功能描述:ISL29040IROMZ-EVALZ (PB-FREE ) EVALUATION BOARD - ROHS COMPL - Bulk