ISL29030AIROZ-T7 Intersil, ISL29030AIROZ-T7 Datasheet - Page 10

• Manufacturer Part Number: ISL29030AIROZ-T7
• Description: IC PROXIMITY SENSOR AMB LT 8ODFN
• Manufacturer: Intersil

Specifications of ISL29030AIROZ-T7

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

110mA current pulse. If this bit is high, the load on IRDR sees a
fixed 220mA current pulse, as shown in Figure 4.
When the IR from the LED reaches an object and gets reflected
back into the ISL29030A, the reflected IR light is converted into
current, as shown by the IR spectral response in Figure 7. One
entire proximity measurement takes 0.54ms for one conversion
(which includes 0.1ms spent driving the LED), and the period
between proximity measurements is decided by PROX_SLP
(sleep time) in Register 1 Bits 6:4.
Average LED driving current consumption is given by Equation 1.
A typical IRDR scheme is 220mA amplitude pulses every 800ms,
which yields 28μA DC.
Total Current Consumption
Total current consumption is the sum of I
pin sinks current (as shown in Figure 4), and the average IRDR
current can be calculated using Equation 1. I
voltage and the mode of operation, as shown in Figure 11.
Interrupt Function
The ISL29030A has an intelligent interrupt scheme designed to
shift some logic processing away from intensive microcontroller
I
independent light sensor that can instruct a system to “wake up”
or “go to sleep.”
An ALS interrupt event (ALS_FLAG) is governed by Registers 5
through 7. The user writes high and low threshold values to these
registers, and the ISL29030A issues an ALS interrupt flag if the
actual counts stored in Registers 0x9 and 0xA are outside the
user-programmed window. The user must write 0 to clear the
ALS_FLAG.
A proximity interrupt event (PROX_FLAG) is governed by the high
and low thresholds in Registers 3 and 4 (PROX_LT and
PROX_HT). PROX_FLAG is set when the measured proximity data
is greater than the high threshold a user-specified consecutive
number of times (X; set by the user; see next paragraph). The
proximity interrupt flag is cleared when the proximity data is
lower than the low proximity threshold X consecutive times, or
when the user writes “0” to PROX_FLAG.
Interrupt persistency is another useful option available for both
ALS and proximity measurements. Persistency requires a user-
specified number (X) of consecutive interrupt flags before the INT
pin is driven low. Both ALS and Prox have their own independent
I
lRDR AVG
2
C polling routines (which consume power) and toward a more
(
)
(PROX_DR = 1)
=
FIGURE 4. CURRENT DRIVE MODE OPTIONS
(PROX_DR = 0)
I
------------------------------------------------------- -
220mA
lRDR PEAK
110mA
T
SLEEP
(
(IRDR IS HI-Z WHEN
+
NOT DRIVING)
)
540μs
×
100μs
10
DD
and I
DD
depends on
IRDR
PIN 8 - IRDR
. The IRDR
ISL29030A
(EQ. 1)
interrupt persistency options. See ALS_PRST and PROX_PRST
bits in Register 2.
The final interrupt option is the ability to AND or OR the two
interrupt flags using Register 2 Bit 0 (INT_CTRL). If the user
wants simultaneous ALS and Prox interrupts to happen before
changing the state of the interrupt pin, the user sets this bit high.
If the user wants the interrupt pin to change state when either
the ALS or the Proximity interrupt flag goes high, the user leaves
this bit at its default value of 0.
Analog-Out I
When ALS_EN = 1, the analog I
directly proportional to the digital count stored in register bits
ALSIRDATA[11:0]. When ALS_EN = 0, this pin is in a high
impedance state. See Figure 15 for the effects of the compliance
voltage (V
ALS Range 1 Considerations
When measuring ALS counts higher than 1800 on range 1
(ALSIR_MODE = 0, ALS_RANGE = 0, ALS_DATA > 1800), the user
must switch to range 2 (change the ALS_RANGE bit from 0 to 1)
and re-measure ALS counts. This recommendation pertains only
to applications where the light incident upon the sensor is
IR-heavy and is distorted by tinted glass that increases the ratio
of infrared to visible light.
V
Considerations
At power-up, ensure a V
power-up, or if the power supply temporarily deviates from the
factory specification (2.25V to 3.63V), Intersil recommends the
user write the following: 0x00 to register 0x01, 0x29 to register
0x0F, 0x00 to register 0x0E, and 0x00 to register 0x0F. The user
should then wait ~1ms or more and then rewrite all registers to
the desired values. If the user prefers a hardware reset method
instead of writing to test registers, then set V
or more, power up again at the required slew rate, and write the
desired values to the registers.
Power-Down
The user can set power-down in two ways. The first is to set both
PROX_EN and ALS_EN bits to 0 in Register 1. The second and
more simple way is to set all bits in Register 1 to 0 (0x00).
Calculating Lux
When in ALS mode, the ISL29030A ADC output codes are directly
proportional to lux (see ALSIR_MODE bit).
In Equation 2, E
represents the ADC code. The constant, α, which is to plug in, is
determined by the range bit, ALS_RANGE (register 0x1 bit 1) and
is independent of the light source type.
E
calc
DD
=
Power-up and Power Supply
α
RANGE
I_ALS
) on I
calc
×
ALS
OUT
ALS
is the calculated lux reading, and OUT
ADC
Pin
.
DD
slew rate of 0.5V/ms or greater. After
ALS
output pin sources a current
DD
= 0V for 1 second
March 31, 2011
FN7722.1
(EQ. 2)