SB040172025 – LIGHT INTENSITY SENSOR SCHEMATIC BLOCK

This schematic block features the LTR‑329ALS‑01, a low‑voltage, I²C‑digital ambient light sensor in a miniature 4‑pin VDFN package. It’s designed to measure a wide range of illumination levels with high resolution and low power consumption, making it ideal for portable and display-dimming applications.

The sensor integrates two photodiodes, internal temperature compensation, and an ADC with selectable gain. It provides digital lux readings via I²C, simplifying the interface and removing the need for complex analog front-end design.

Key Features:

• Digital I²C interface (Fast Mode, 400 kbit/s)
• Wide dynamic range: approximately 0.01 lux to 64,000 lux
• Six gain settings (1×, 2×, 4×, 8×, 48×, 96×) for flexible sensitivity
• Close-to-human-eye spectral response with IR and UV immunity
• Flicker rejection (50/60 Hz lighting) built in
• Built-in temperature compensation for stable readings
• Very low active power consumption (~250 µA)
• Ultra-low standby current (~5 µA)
• Supply voltage: 2.4 V to 3.6 V
• Logic-level interface voltage: as low as 1.7 V
• Operating temperature range: –30 °C to +70 °C

Typical Applications:

• Display backlight control (phones, tablets, monitors)
• Ambient brightness sensing in consumer electronics
• Power-saving lighting systems
• Smart home sensors and IoT lighting control
• Environmental light monitoring
• Portable devices that need ambient light feedback

By integrating this Quickboards schematic block, engineers can quickly prototype light-based control systems, reduce analog complexity, and use a compact, power-efficient sensor for reliable ambient light measurement.