TMD27721 Datasheet, PDF (27/35 Pages) TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS – DIGITAL ALS and PROXIMITY MODULE

TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
ADC Channel Data Registers (0x14 − 0x17)
ALS data is stored as two 16-bit values. To ensure the data is read correctly, a two-byte read I²C transaction
should be used with auto increment protocol bits set in the command register. With this operation, when the
lower byte register is read, the upper eight bits are stored in a shadow register, which is read by a subsequent
read to the upper byte. The upper register will read the correct value even if additional ADC integration cycles
end between the reading of the lower and upper registers.
REGISTER
lid ^C0DATA
C0DATAH
C1DATA
a _C1DATAH
Table 18. ADC Channel Data Registers
ADDRESS
0x14
0x15
0x16
0x17
BITS
7:0
7:0
7:0
7:0
DESCRIPTION
ALS CH0 data low byte
ALS CH0 data high byte
ALS CH1 data low byte
ALS CH1 data high byte
v _{Proximity Data Registers (0x18 − 0x19)}
ill ^{Proximity data is stored as a 16-bit value. To ensure the data is read correctly, a two-byte read I2C transaction}
should be utilized with auto increment protocol bits set in the command register. With this operation, when the
t _{lower byte register is read, the upper eight bits are stored into a shadow register, which is read by a subsequent}
G ^{read to the upper byte. The upper register will read the correct value even if the next ADC cycle ends between}
s _{the reading of the lower and upper registers.}
s A nt REGISTER
PDATAL
e _PDATAH
Table 19. Proximity Data Registers
ADDRESS
0x18
0x19
BITS
7:0
7:0
DESCRIPTION
Proximity data low byte
Proximity data high byte
am ^nt _{Proximity Offset Register (0x1E)}
o _{The 8-bit proximity offset register provides compensation for proximity offsets caused by device variations,}
c _{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
l _{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
a _{contribute to proximity offset, this register is best suited for use in an adaptive closed-loop control system. See}
available TAOS application notes for proximity offset register application information.
ic_{Table 20. Proximity Offset Register}
hn _POFFSET
c _FIELD
Te ^SIGN
7
SIGN
BIT
7
6
5
4
3
2
1
0
MAGNITUDE
Reset
0x00
DESCRIPTION
Proximity Offset Sign. The offset sign shifts the proximity data negative when equal to 0 and positive when
equal to 1.
Proximity Offset Magnitude. The offset magnitude shifts the proximity data positive or negative, depending
MAGNITUDE
6:0
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).
Copyright E 2012, TAOS Inc.
r
The LUMENOLOGY r Company
r
26
www.taosinc.com