Si1120 PROXIMITY/AMBIENT LIGHT SENSOR WITH PWM OUTPUT Features Pin Assignments Typically 50 cm meter proximity High EMI immunity without range with single pulse shielded packaging Si1120 Seven precision optical Power supply: 2.23.7 V ODFN measurement modes: Operating temperature range: 3 proximity ranges 40 to +85 C PRX 1 8 VSS 3 dc ambient ranges Typical 10 A current MD TXGD 2 7 1 calibration mode consumption TXO 3 6 Low-noise ambient cancelling SC Programmable 400/50 mA LED circuit allows maximum STX 4 5 VDD constant current driver output sensitivity with 812 bit resolution Allows independent LED supply ALS works in direct sunlight voltage (100 klux) U.S. Patent 5,864,591 Small outline 3 x 3 mm (ODFN) Minimum reflectance sensitivity U.S. Patent 6,198,118 2 <1 W/cm Other patents pending Applications Handsets Notebooks/PCs Touchless switches Industrial automation Occupancy sensors Display backlighting control Consumer electronics Photo-interrupter Description 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. Rev. 1.0 8/10 Copyright 2010 by Silicon Laboratories Si1120 Not Recommended for New DesignsSi1120 Functional Block Diagram Ambient Light Sources Transparent Transparent window window MUX AMP CMP PWM PRX Output Infrared BUF emitter IR VIS VDD Product RAMP VREG GEN Case STX TXO Optical Block MODE SC TX CTRL MD VSS TXGD 3.3 V P0.0/VREF VDD / DC+ C1 Si1120 1.0 uF P0.1 / AGND P0.2 / XTAL1 VSS PRX GND / DC- P0.3 / XTAL2 P0.4 / TX MD TXGD P0.5 / RX P0.6 / CNVSTR SC TXO P0.7 / IREF0 VDD STX P1.0 C8051F931 P1.1 P1.2 DCEN P1.3 P1.4 VBAT R1 P1.5 TX LED 30 ohm P1.6 C2 C3 XTAL3 C4 10 uF 0.1 uF XTAL4 68.0 uF GND RST / C2CK P2.7 / C2D Figure 1. Si1120 Typical Application Example of Digital Proximity and Ambient Light Sensor with 2 C8051F931 MCU and I C Interface 2 Rev. 1.0 Not Recommended for New Designs