Digital Proximity Sensor with Interrupt Function

Product Status: Mass Production


The ISL29021 is an integrated proximity and infrared sensor with a built-in IR LED driver and I2 C Interface (SMBus Compatible). This device provides infrared sensing to allow proximity estimation featured with interrupt function.

For infrared and proximity sensing, an internal ADC has been designed based on the charge-balancing A/D conversion technique.

The ADC is used to digitize the output signal from the photodiode array when the internal IR LED driver is turned on and off for the programmed time periods under user-selected modulation frequency to drive the external IR LED. As this proximity sensor employs a noise cancellation scheme to highly reject unwanted IR noise, the digital output of proximity sensing decreases with distance. The driver output current is user selectable up to 100mA to drive different types of IR emitters LEDs.

Four different modes of operation can be selected via the I2 C interface: programmable IR sensing once, programmable proximity sensing once, programmable continuous IR sensing and programmable continuous proximity sensing. The programmable one-time operation modes greatly reduce power because an immediate automatic shutdown reduces overall supply current less than 0.5µA.

The ISL29021 supports both hardware and software interrupts that remain asserted until the host clears it through I2 C interface for proximity detection.

Designed to operate on supplies from 2.5V to 3.63V, the ISL29021 is specified for operation over the -40°C to +85°C ambient temperature range. It is packaged in a clear, Pb-free 8 Ld ODFN package.


    Proximity Sensing
  • Ambient IR Cancellation During Proximity Sensing
  • Works Under Direct Sunlight
  • IR LED Driver with Programmable Source Current
  • Adjustable Current Drive from 100mA to 12.5mA
  • Programmable LED current Modulation Frequency
  • Variable Conversion Resolution up to 16-bits
  • Selectable Range (via I2C)
  • Works Under Various Light Sources, Including Sunlight

  • Ideal Spectral Response for Proximity Sensor
  • Proximity sensor range from 850nm to 950nm
  • Can use either 850nm or 950nm LED solution

  • Ultra Low Power
  • 90µA Max Operating Current
  • Software Shutdown and Automatic Shutdown
  • 0.5µA Max Shutdown Current

  • Easy to Use
  • I2C (SMBus Compatible) Output
  • No Complex Algorithms Needed
  • Temperature Compensated
  • Small Form Factor
  • 8 Ld 2.0mmx2.1mmx0.7mm ODFN Package

  • Additional Features
  • I2C and SMBus Compatible
  • 1.7V to 3.63V Supply for I2C Interface
  • 2.25V to 3.63V Sensor Power Supply
  • Pb-Free (RoHS Compliant)


 Block Diagram


Basic Information
Production Status
Mass Production
Peak Spectral Sensitivity
825 nm
VS (min)
2.25 V
VS (max)
3.63 V
Resolution Bits
Lux Range (max) (lux)
Counts/Lux (max) (Counts)
Dark ADC Code @ Ev=0Lux (max) (Counts)
Gain Selection?
Qualification Level
Bus/Output Interface
Address Selection Pins?
Package Dimensions (mm)
Enable Pin?
Can Sample
Temperature Range
-40 to +85

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