OPT4001-Q1

The OPT4001-Q1 is a light-to-digital sensor (single-chip lux meter) that measures the intensity of visible light. To measure accurate light intensity, a specially engineered filter on the device tightly matches the photopic response of the human eye and rejects the near-infrared component from common light sources. The output of the OPT4001-Q1 is semi-logarithmic with nine binary logarithmic full-scale light ranges along with a highly linear response within each range, providing measurement capability from 400µlux to 107klux. This capability allows the light sensor to have a 28-bit effective dynamic range. The built-in automatic range-selection logic dynamically adjusts the device gain settings based on the light level, providing the best possible resolution in all conditions without user input.

The engineered optical filter on the OPT4001-Q1 provides strong near infrared (NIR) rejection. This filter aids in maintaining high accuracy when the sensor is placed under dark glass for aesthetic reasons.

The OPT4001-Q1 is designed for systems that require light level detection to enhance user experience and typically replaces low-accuracy photodiodes, photoresistors, and other ambient light sensors with underwhelming human eye matching and near-infrared rejection.

The OPT4001-Q1 can be configured to operate with light conversion times from 600µs to 800ms in 12 steps, providing system flexibility based on application need. Conversion time includes the light integration time and analog-to-digital (ADC) conversion time. Measurement resolution is determined by a combination of light intensity and integration time, effectively providing the capability to measure down to 400µlux of light intensity changes.

Digital operation is flexible for system integration. Measurements can be either continuous or triggered in one shot with register writes or a hardware pin. The device features a threshold detection logic, which allows the processor to sleep while the sensor waits for an appropriate wake-up event to report through the interrupt pin.

The sensor reports a digital output representing the light level over an I2C- and SMBus-compatible, two-wire serial interface. An internal first-in-first-out (FIFO) on the output registers is available to read out measurements from the sensor at a slower pace while still preserving all data captured by the device. The OPT4001-Q1 also supports I2C burst mode, thus helping the host read data from the FIFO with minimal I2C overhead.

The low power consumption and low power-supply voltage capability of the OPT4001-Q1 helps enhance the battery life of battery-powered systems.