ISL29021_14 Datasheet, PDF (6/12 Pages) Intersil Corporation – Digital Proximity Sensor with Interrupt Function

ISL29021
Register Set
There are eight registers that are available in the ISL29021. Table 1 summarizes their functions.
TABLE 1. REGISTER SET
BIT
ADDR REG NAME
7
6
5
4
3
2
1
00h COMMANDI OP2
OP1
OP0
0
0
FLAG
PRST1
01h COMMANDII
1
FREQ
IS1
IS0
RES1
RES0 RANGE1
02h
DATA_LSB
D7
D6
D5
D4
03h
DATA_MSB
D15
D14
D13
D12
04h INT_LT_LSB TL7
TL6
TL5
TL4
D3
D2
D1
D11
D10
D9
TL3
TL2
TL1
05h INT_LT_MSB TL15
TL14
TL13
TL12
TL11
TL10
TL9
06h INT_HT_LSB TH7
TH6
TH5
TH4
TH3
TH2
TH1
07h INT_HT_MSB TH15
TH14
TH13
TH12
TH11
TH10
TH9
0
PRST0
RANGE0
D0
D8
TL0
TL8
TH0
TH8
DEFAULT
00h
00h
00h
00h
00h
00h
FFh
FFh
Command Register I 00(hex)
The first command register has the following functions:
1. Operation Mode: Bits 7, 6, and 5.These three bits
determines the operation mode of the device.
TABLE 2. OPERATION MODE
BITS 7 TO 5
OPERATION
000
Power-down the device
001
Reserved (Do not use)
010
IR once
011
Proximity once
100
Reserved (Do not use)
101
Reserved (Do not use)
110
IR continuous
111
Proximity continuous
2. Interrupt flag; Bit 2. This is the status bit of the interrupt.
The bit is set to logic high when the interrupt thresholds
have been triggered, and logic low when not yet triggered.
Once triggered, INT pin stays low and the status bit stays
high. Both interrupt pin and the status bit are automatically
cleared at the end of Command Register I transfer.
TABLE 3. INTERRUPT FLAG
BIT 2
OPERATION
0
Interrupt is cleared or not triggered yet
1
Interrupt is triggered
3. Interrupt persist; Bits 1 and 0. The interrupt pin and the
interrupt flag is triggered/set when the data sensor
reading is out of the interrupt threshold window after m
consecutive number of integration cycles. The interrupt
persist bits determine m.
.
TABLE 4. INTERRUPT PERSIST
BITS 1 TO 0
NUMBER OF INTEGRATION CYCLES
00
1
01
4
10
8
11
16
Command Register II 01(hex)
The second command register has the following functions:
1. Proximity Sensing Scheme: Bit 7. This bit programs the
function of the proximity detection. Logic 1 of this bit,
Scheme 1, makes n-1 (3, 7, 11, 15) bits (2’s
complementary) proximity_less_ambient detection. The
range of Scheme 1 proximity count is from -2^(n-1) to
2^(n-1), Scheme 1 proximity detection is less affected by
the ambient IR noise variation.
TABLE 5. PROXIMITY SENSING SCHEME
BIT 7
OPERATION
0
Reserved
1
Sensing IR from LED with ambient IR rejection
2. Modulation Frequency: Bits 6. This bit sets the IR LED
driver’s modulation frequency.
TABLE 6. MODULATION FREQUENCY
BITS 6
MODULATION FREQUENCY
(kHz)
0
DC
1
360
3. Amplitude of IR driver current: Bits 5 and 4. This device
provides current source to drive an external IR LED. The
drive capability can be programmed through Bits 5 and 4.
For example, the device sources 12.5mA out of the IRDR
pin if Bits 5 and 4 are 0.
6
FN6732.0
March 3, 2009