TMD26721 datasheet(5/44 Pages) OSRAM

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[v1-00] 2015-Mar-23

TMD2672 − Detailed Description

A fully integrated proximity detection solution is provided with

an 850nm IR LED, LED driver circuit, and proximity detection

engine. An internal LED driver (LDR) pin, is externally connected

to the LED cathode (LEDK) to provide a controlled LED sink

current. This is accomplished with a proprietary current

calibration technique that accounts for all variances in silicon,

optics, package, and most important, IR LED output power. This

eliminates or greatly reduces the need for factory calibration

that is required for most discrete proximity sensor solutions.

The device is factory calibrated to achieve a proximity count

reading at a specified distance with a specific number of pulses.

In use, the number of proximity LED pulses can be programmed

from 1 to 255 pulses, which allows different proximity distances

to be achieved. Each pulse has a 16μs period, with a 7.2μs on

time.

The device provides a separate pin for level-style interrupts.

When interrupts are enabled and a pre-set value is exceeded,

the interrupt pin is asserted and remains asserted until cleared

by the controlling firmware. The interrupt feature simplifies and

improves system efficiency by eliminating the need to poll a

sensor for a proximity value. An interrupt is generated when the

value of a proximity conversion exceeds either an upper or

lower threshold. In addition, a programmable interrupt

persistence feature allows the user to determine how many

consecutive exceeded thresholds are necessary to trigger an

interrupt.

Detailed Description

TMD26721 数据表(PDF) 5 Page - OSRAM GmbH