TSL27713FN TAOS, TSL27713FN Datasheet - Page 13

• Manufacturer Part Number: TSL27713FN
• Description: Light to Digital Converters Light to Digital w/Proximity
• Manufacturer: TAOS

Specifications of TSL27713FN

• Data Bus Width: 16 bit
• Peak Wavelength: 640 nm, 850 nm
• Maximum Operating Frequency: 795 KHz
• Operating Supply Voltage: 2.4 V to 3.6 V
• Operating Current: 175 uA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: - 30 C
• Interface Type: I2C
• Maximum Fall Time: 300 ns
• Maximum Rise Time: 300 ns
• Mounting Style: SMD/SMT
• Resolution: 16 bit
• Package / Case: DFN-6
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Proximity Detection
The LUMENOLOGY r Company
Proximity sensing uses an external light source (generally an infrared emitter) to emit light, which is then viewed
by the integrated light detector to measure the amount of reflected light when an object is in the light path
(Figure 10). The amount of light detected from a reflected surface can then be used to determine an object’s
proximity to the sensor.
The TSL2771 has controls for the number of IR pulses (PPCOUNT), the integration time (PTIME), the LED drive
current (PDRIVE), and the photodiode configuration (PDIODE) (Figure 11). The photodiode configuration can
be set to infrared diode (recommended), clear diode, or a combination of both diodes. At the end of the
integration cycle, the results are latched into the proximity data (PDATA) register.
The LED drive current is controlled by a regulated current sink on the LDR pin. This feature eliminates the need
to use a current limiting resistor to control LED current. The LED drive current can be configured for 12.5 mA,
25 mA, 50 mA, or 100 mA. For higher LED drive requirements, an external P type transistor can be used to
control the LED current.
The number of LED pulses can be programmed to any value between 1 and 255 pulses as needed. Increasing
the number of LED pulses at a given current will increase the sensor sensitivity. Sensitivity grows by the square
root of the number of pulses. Each pulse has a 16-μs period.
LED
IR
Surface Reflectivity (SR)
Background Energy (BGE)
V
Figure 11. Proximity Detection Operation
DD
Figure 10. Proximity Detection
r
Clear
PDRIVE(r 0x0F, b7:6)
Integration
IR LED Constant
www.taosinc.com
Current Sink
Prox
Distance (D)
Prox Control
IR
Prox
ADC
PTIME(r 2)
PPCOUNT(r 0x0E)
Optical Crosstalk (OC)
Glass Attenuation (GA)
Prox
Data
LIGHT-TO-DIGITAL CONVERTER
r
PDATAH(r 0x019), PDATAL(r 0x014)
IR LED
with PROXIMITY SENSING
2771
TAOS100A − FEBRUARY 2010
Copyright E 2010, TAOS Inc.
TSL2771
13