Si1120 Proximity/Ambient Light Sensor with PWM Output Description Features The Si1120 is a low-power, reflectance-based proximity and ambient light sensor with advanced analog signal processing and analog PWM output. It includes an integrated differential photodiode, signal processor, and LED driver. Proximity sensing is based on the measurement of reflected light from an external, optically-isolated, strobed LED. A separate visible light photodiode is used for ambient light sensing. The standard package for the Si1120 is an 8-pin ODFN. - 0-1/2 meter proximity range with single pulse - 7 precision optical measurement modes - 3 Proximity ranges - 3 dc ambient ranges - 1 calibration mode - Low-noise ambient cancelling circuit allows maximum sensitivity with 8-12 bit resolution - Works in direct sunlight (100 klux) - Minimum reflectance sensitivity <1 W/cm2 - High EMI immunity without shielded packaging - Power supply: 2.2-3.7 V - Operating temperature range: -40 to +85 C - Typical 10 A current consumption - Programmable 400/50 mA LED constant current driver output - Allows independent LED supply voltage - Small outline 3 x 3 mm (ODFN) - U.S. Patents 5,864,591 and 6,198,118 (others pending) Applications - IC1 IC2 MUX Handsets Touchless switches Occupancy sensors Consumer electronics Notebooks/PCs Industrial automation Display backlighting control Photo-interrupter AMP CMP PRX BUF IR VIS RAMP GEN VDD VREG STX SC TXO MODE CTRL TX MD VSS Human Interface Products Copyright (c) 2009 by Silicon Laboratories TXGD 5.18.09 Si1120 Proximity/Ambient Light Sensor with PWM Output Selected Electrical Specifications (TA = -40 to +85 C unless otherwise specified) Parameter Supply Voltage Conditions Min Typ Max Units -40 to +85 C, VDD to VSS 2.2 3.3 3.7 V -40 -- 85 C 2000 s 100 klux 1.0 A Operating Temperature PRX pulse width range VDD = 3.3 V DC Ambient light (Edc) VDD = 3.3 V 4 IDD Shutdown SC = VDD = 2.2 to 3.7 V 0.1 IDD idle current SC = STX = 0 V, VDD = 3.3 V 120 A IDD current during transmit, not saturated LED I = 50 mA, VDD = 3.3 V 3 A VDD = 3.7 V 1 W/cm2 Min. Detectable Reflectance Input 8-Pin ODFN Package Pin Assignments Si1120 ODFN-8 PRX 1 8 VSS TXGD 2 7 MD TXO 3 6 SC STX 4 5 VDD Symbol A b D D2 e E E2 L aaa bbb ccc ddd Min 0.55 0.25 1.40 2.20 0.30 Millimeters Typ 0.65 0.30 3.00 BSC. 1.50 0.65 BSC. 3.00 BSC. 2.30 0.35 0.10 0.10 0.08 0.10 Max 0.75 0.35 1.60 2.40 0.40 Product Family Part Number Pkg LED Drivers LED Drive Methods Range Measurement Modes Resolution Si1120-A-GM ODFN-8 1 Current Driven (400 mA), Saturated 50 cm 3 Proximity 3 DC Ambient 1 Calibration 8 to 12 bits Human Interface Products Copyright (c) 2009 by Silicon Laboratories Silicon Laboratories and Silicon Labs are trademarks of Silicon Laboratories Inc. Other products or brandnames mentioned herein are trademarks or registered trademarks of their respective holders. 5.18.09