TSL27721 datasheet(42/56 Pages) AMSCO

42 / 56 page

Page 42

ams Datasheet

Document Feedback

[v1-00] 2016-Aug-26

TSL2772 − Principles O f Operation

Proximity Offset Register (0x1E)

The 8-bit proximity offset register provides compensation for

proximity offsets caused by device variations, optical crosstalk,

and other environmental factors. Proximity offset is a

sign-magnitude value where the sign bit, bit 7, determines if

the offset is negative (bit 7 = 0) or positive (bit 7 = 1). At power

up, the register is set to 0x00. The magnitude of the offset

compensation depends on the proximity gain (PGAIN),

proximity LED drive strength (PDRIVE), and the number of

proximity pulses (PPULSE). Because a number of environmental

factors contribute to proximity offset, this register is best suited

for use in an adaptive closed-loop control system. See available

ams application notes for proximity offset register application

information.

Figure 46:

Proximity Offset Register

SIGN

MAGNITUDE

Field

Bit

Description

SIGN

Proximity Offset Sign. The offset sign shifts the proximity data negative when equal to

0 and positive when equal to 1.

MAGNITUDE

6:0

Proximity Offset Magnitude. The offset magnitude shifts the proximity data positive

or negative, depending on the proximity offset sign. The actual amount of the shift

depends on the proximity gain (PGAIN), proximity LED drive strength (PDRIVE), and

the number of proximity pulses (PPULSE).

TSL27721 Arkusz danych(PDF) 42 Page - ams AG