Si1120-A-GM Silicon Laboratories Inc, Si1120-A-GM Datasheet
Si1120-A-GM
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Si1120-A-GM Summary of contents
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... Occupancy sensors Consumer electronics 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 ...
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... Infrared emitter Product Case Optical Block 3.3 V VDD / DC+ C1 1.0 uF GND / DC- C8051F931 DCEN VBAT GND Figure 1. Si1120 Typical Application Example of Digital Proximity and Ambient Light Sensor with 2 Ambient Light Sources Transparent window MUX AMP IR VIS RAMP GEN STX MODE SC CTRL ...
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... Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 2.3. Proximity Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 2.4. Ambient-Light Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.5. Choice of LED and LED Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.6. Power-Supply Transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 2.7. Practical Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3. Pin Descriptions—Si1120 (ODFN Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5. Photodiode Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6. Package Outline (8-Pin ODFN .18 Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Rev ...
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Si 1120 1. Electrical Specifications Table 1. Absolute Maximum Ratings* Parameter Supply Voltage Operating Temperature Storage Temperature Voltage on TXO with respect to GND Voltage on all other Pins with respect to GND Maximum Total Current through TXO (TXO active) ...
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... TXO = 1 V (Mode 0) Itxo TXO = 1 V (Mode 2, 3 FSals1 V = 3.3 V, Mode 5 DD FSals2 V = 3.3 V, Mode 6 DD FSals3 V = 3.3 V, Mode 7 DD Rev. 1.0 Si1120 Min Typ Max Units — 0.1 1.0 µA — 90 150 µA — 14 — mA — 3 — mA 0.5 — ...
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... For small objects, the drop in reflectance is as much as the fourth power of the distance; this means that there is less range ambiguity than with passive motion-based devices. For example, a sixteen-fold change in an object's reflectance means only a fifty-percent drop in detection range. The Si1120 periodically measures proximity at a rate that can be set by an external controller. ...
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... SC goes back low. Following a mode change, STX must be kept low during the power-up latency period. If the host sets STX too early, the Si1120 may not begin a measurement cycle; PRX does not assert. If this occurs, the host can restart a measurement by toggling STX. ...
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... In proximity mode, an LED sends light pulses that are reflected from the target to a photodiode and processed by the Si1120’s analog circuitry. Light reflected from a proximate object is detected by the receiver, and the Si1120 converts the light signal into a pulse at the PRX output of a duration proportional to the amount of reflected light. ...
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... Hand, 300 Lux Fluorescent 47%, Hand, 300 Lux Incandescent 18% Gray Card, 1 Lux 92% White Card, 1 Lux 1000 1200 1400 1600 1800 47%, Hand, 1 Lux 47%, Hand, 300 Lux Fluorescent 47%, Hand, 300 Lux Incandescent 18% Gray Card, 1 Lux 92% White Card, 1 Lux 150 200 250 Rev. 1.0 Si1120 2000 300 9 ...
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Si 1120 200 400 Figure 7. Combined PRX400 and PRX50 10 18% Gray Card, 400 mA 18% Gray Card 92% White, 400 mA 92% White 600 ...
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... The Si1120 has two photodiodes, each of which peaks at a different wavelength. The VAMB mode uses the visible light photodiode which peaks at around 530 nm. On the other hand, the VIRH and VIRL modes use the photodiode which peaks at around 830 nm ...
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... Si 1120 1 0.9 0.8 0.7 0.6 0.5 VAMB 0.4 0.3 0.2 0.1 0 400 500 600 700 800 Wavelength (nm) Figure 9. Si1120 Typical Spectral Response 100 100 200 300 400 500 VIRH Pulse Width (VIRL, VAMB saturated) Figure 10. Sunlight Transfer Function 140 120 100 80 ...
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... Figure 15. Lux/VIRL Ratio vs. Color Ratio 0.09 0.1 Rev. 1.0 Si1120 13 ...
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... Supply transients occurring after the LED has been turned off have no effect since the proximity state is latched until the next cycle. The Si1120 itself produces sharp current transients, and, for this reason, must also have a bulk capacitor on its supply pins. Current transients at the Si1120 supply can mA. ...
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... Practical Considerations It is important to have an optical barrier between the LED and the Si1120. The reflection from objects to be detected can be very weak since, for small objects within the LED's emission angle, the amplitude of the reflected signal decreases in proportion with the fourth power of the distance. The receiver can detect a signal with an 2 irradiance of 1 µ ...
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... Si 1120 3. Pin Descriptions—Si1120 (ODFN) Pin Name 1 PRX PWM Output. Outputs a low-going PWM pulse proportional to signal. 2 TXGD TXGD. Power ground (LED and PRX driver ground return). Must be connected to VSS. 3 TXO Transmit Output. Normally connected to an infrared LED cathode. The output current is a programmable con- stant current sink ...
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... Ordering Guide Part Ordering # Si1120-A-GM 5. Photodiode Centers Temperature Package –40 to +85 °C 3x3 mm ODFN8 Rev. 1.0 Si1120 17 ...
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... Si 1120 6. Package Outline (8-Pin ODFN) Figure 18 illustrates the package details for the Si1120 ODFN package. Table 6 lists the values for the dimensions shown in the illustration. Figure 18. ODFN Package Diagram Dimensions Table 6. Package Diagram Dimensions Dimension aaa bbb ccc ddd Notes: 1. All dimensions shown are in millimeters (mm). ...
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... TYP and 300 µA Max to 150 µA Max. Updated first paragraph in "2.4. Ambient-Light Modes" on page 11. Renamed Section “2.7. Mechanical and Optical Implementation” to “2.7. Practical Considerations” . Added factory calibration guidance. Added "5. Photodiode Centers" on page 17. Rev. 1.0 Si1120 19 ...
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