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Numéro de sérieISL29020
CategorieInterface and Interconnect => I2C
DescriptionA Low Power, High Sensitivity, Light-to Digital Sensor With I2C Interface
The ISL29020 is a low power, high sensitivity, integrated light sensor with I2C (SMBus Compatible) interface. Its state-of-the-art photodiode array provides close-to human eye response and good IR rejection. This ADC is capable of rejecting 50Hz and 60Hz flicker caused by artificial light sources. The lux range select feature allows the user to program the lux range for optimized counts/lux.
SociétéIntersil Corporation
DatasheetTélécharger ISL29020 datasheet
 
 
  • Description courte

  • A Low Power, High Sensitivity, Light-to Digital Sensor With I2C Interface

    The is a low power, high sensitivity, integrated light sensor with I2C (SMBus Compatible) interface. Its state-of-the-art photodiode array provides close-to human eye response and good IR rejection. This ADC is capable of rejecting 50Hz and 60Hz flicker caused by artificial light sources. The lux range select feature allows the user to program the lux range for optimized counts/lux. In normal operation, typical power consumption 55µA. In order to further minimize power consumption, two power-down modes have been provided. If polling is chosen over continuous measurement of light, the auto-power-down function shuts down the whole chip after each ADC conversion for the measurement. The other power-down mode is controlled by software via the I2C interface. The power consumption can be reduced to less than 1µA when powered down. Designed to operate on supplies from to 3.3V with I2C supply from to 3.6V, the ISL29020 is specified for operation over the to +85°C ambient temperature range.

    Features

    · Low Power - 65µA Max Operating Current - 0.5µA Max Shutdown Current - Software Shutdown and Automatic Shutdown· Ideal Spectral Response - Close to Human Eye Response - Excellent IR and UV Rejection· Easy to Use - Simple Output Code Directly Proportional to lux - I2C (SMBus Compatible) Output - No Complex Algorithms Needed - Variable Conversion Resolution 16-bits - Adjustable Sensitivity to 65 Counts per lux - Works Under Various Light Sources, Including Sunlight - Selectable Range (via I2C) - Range = 0.015 lux to 1,000 lux - Range = 0.06 lux to 4,000 lux - Range = 0.24 lux to 16,000 lux - Range = 0.96 lux to 64,000 lux - Temperature Compensated - Integrated 50/60Hz Noise Rejection· Small Form Factor 6 Ld ODFN Package

    PART NUMBER (Note) ISL29020IROZ-T7* ISL29020IROZ-EVALZ PACKAGE (Pb-Free) 6 Ld ODFN PKG. DWG. # L6.2x2.1

    *Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and NiPdAu plate - e4 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.

    · Additional Features - I2C and SMBus Compatible to 3.6V Supply for I2C Interface to 3.3V Supply - Address Selection Pin· Pb-Free (RoHS compliant)

    Applications

    · Display and keypad dimming for: - Mobile devices: smart phone, PDA, GPS - Computing devices: notebook PC, webpad - Consumer devices: LCD-TV, digital picture frame, digital camera· Industrial and medical light sensing

    CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2008. All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

    VDD Supply Voltage between VDD and GND. 3.6V I2C Bus Pin Voltage (SCL, SDA). 3.6V I2C Bus Pin Current (SCL, SDA). <10mA REXT, A0 Pin Voltage. -0.2V to VDD ESD Rating Human Body Model.2kV

    Thermal Resistance JA (°C/W) 6 Ld ODFN. 88 Maximum Die Temperature. +90°C Storage to +100°C Operating to +85°C Pb-Free Reflow Profile.see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp

    CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: = TA

    PARAMETER VDD IDD IDD1 VI2C fOSC tint FI2C DATA_0 DATA_F DATA DATA_IR3 DATA_IR4 VREF VIL VIH ISDA NOTES:

    VDD = +25°C, REXT 500k 1% tolerance, 16-bit ADC operation, unless otherwise specified. CONDITION MIN 2.25 55 Software disabled or auto power-down 650 16-bit ADC data = 0 lux, Range 1 (1k lux) 5 0.01 TYP MAX UNIT µA V kHz ms kHz Counts

    DESCRIPTION Power Supply Range Supply Current Supply Current when Powered Down Supply Voltage Range for I2C Interface Internal Oscillator Frequency ADC Integration/Conversion Time I2C Clock Rate Range Count Output When Dark Full Scale ADC Code Count Output Variation Over Three Light Ambient light sensing Sources: Fluorescent, Incandescent and Sunlight Light Count Output With LSB of 0.015 lux/count Light Count Output With LSB of 0.06 lux/count Light Count Output With LSB of 0.24 lux/count Light Count Output With LSB of 0.96 lux/count Infrared Count Output Infrared Count Output Infrared Count Output Infrared Count Output Voltage of REXT Pin SCL and SDA Input Low Voltage SCL and SDA Input High Voltage SDA Current Sinking Capability

    = 300 lux, Fluorescent light (Note 1), Ambient light sensing, Range 1 (1k lux) = 300 lux, Fluorescent light (Note 1), Ambient light sensing, Range 2 (4k lux) = 300 lux, Fluorescent light (Note 1), Ambient light sensing, Range 3 (16k lux) = 300 lux, Fluorescent light (Note 1), Ambient light sensing, Range 4 (64k lux) = 210 lux, Sunlight (Note 2), IR sensing, Range = 210 lux, Sunlight (Note 2), IR sensing, Range = 210 lux, Sunlight (Note 2), IR sensing, Range = 210 lux, Sunlight (Note 2), IR sensing, Range 4

    1. 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 fluorscent light. 2. 850nm green 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.

    PIN NUMBER PIN NAME VDD GND REXT A0 SCL SDA DESCRIPTION Positive supply; connect this pin to 3.3V supply. Ground pin. External resistor pin for ADC reference; connect this pin to ground through a (nominal) 500k resistor. Bit of I2C address; ground or tie this pin to VDD. No floating. I2C serial clock I2C serial data The I2C bus lines can be pulled from 1.7V to above VDD, 3.6V max.

    The ISL29020 contains two photodiode arrays which convert light into current. The spectral response for ambient light sensing and IR sensing is shown in Figure 8 in the "Typical Performance Curves" on page 9. After light is converted to current during the light signal process, the current output is converted to digital by a single 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 an AC periodic noise. A 100ms integration time, for instance, highly rejects 50Hz and 60Hz power line noise simultaneously. See "Integration Time or Conversion Time" on page 6 and "Noise Rejection" on page 7. 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 counter inside the ADC. In External Timing Mode, integration time is determined by the time between two consecutive I2C External Timing Mode commands. See "External Timing Mode" on page 6. A good balancing act of integration time and resolution depending on the application is required for optimal results. The ADC has I2C programmable ranges to dynamically accommodate various lighting conditions. For very dim conditions, the ADC can be configured at its lower range (Range 1). For bright conditions, the ADC can be configured at its higher range (Range 2).

    Figure 1 shows a sample one-byte read. Figure 2 shows a sample one-byte write. Figure 3 shows a sync_I2C timing diagram sample for externally controlled integration time. The I2C bus master always drives the SCL (clock) line, while either the master or the slave can drive the SDA (data) line. Every I2C transaction begins with the master asserting a start condition (SDA falling while SCL remains high). The following byte is driven by the master, and includes the slave address and read/write bit. The receiving device is responsible for pulling SDA low during the acknowledgement period. Every I2C transaction ends with the master asserting a stop condition (SDA rising while SCL remains high). For more information about the I2C standard, please consult the Philips® I2C specification documents.

    The ISL29020 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 ISL29020 receives an I2C command do a one-time measurement from an I2C master, it will start light sensing and ADC conversion. 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 ISL29020 will continuously do light sensing and ADC conversion 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.

    There are three 8-bit registers available inside the ISL29020. The command register defines the operation of the device. The command register does not change until the register is overwritten. The two data registers are Read-Only for 16-bit ADC output or timer output. The data registers contain the ADC's or timer's latest digital output. The ISL29020's I2C interface slave address can be selected 1000101 by connecting A0 pin to GND or VDD, respectively. When or 1000101x with W is sent after the Start condition, this device compares the first seven bits of this byte to its address and matches. 3