NOA1305
Ambient Light Sensor with
I2C Interface and Dark
Current Compensation
Description
The NOA1305 ambient light sensor (ALS) is designed for handheld
applications and integrates a 16−bit ADC, a 2−wire I2C digital
interface, internal clock oscillator and a power down mode. The built
in dynamic dark current compensation and precision calibration
capability coupled with excellent IR and 50/60 Hz flicker rejection
enables highly accurate measurements from very low light levels to
full sunlight. The device can support simple count equals lux readings
in interrupt−driven or polling modes. The NOA1305 employs proprietary
CMOS image sensing technology from ON Semiconductor to provide
large signal to noise ratio (SNR) and wide dynamic range (DR) over
the entire operating temperature range. The optical filter used with this
chip provides a light response similar to that of the human eye.
Features
• Senses Ambient Light and Provides an Output Count Proportional to
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
the Ambient Light Intensity
Photopic Spectral Response
Dynamic Dark Current Compensation
IR Rejection Eliminates Need for Additional IR Photodiode
Less than 120 mA Active Power Consumption in Normal Operation
Less than 2 mA Power Dissipation in Power Down Mode
Interrupt Signal Notifies Host of Significant Intensity Changes
Wide Operating Voltage Range (2.4 V to 3.6 V)
Wide Operating Temperature Range (−40°C to 85°C)
Linear Response Over the Full Operating Range
Senses Intensity of Ambient Light from 0.165 Lux to Over 100K Lux
8 Selectable Integration Times Ranging from 6.25 ms to 800 ms
No External Components Required
Built−in 16−bit ADC
I2C Serial Communication Port Supports Standard and Fast Modes
Metal Mask Programmable I2C Slave Address Option Available
These Devices are Pb−Free and are RoHS Compliant
http://onsemi.com
CUDFN6
CU SUFFIX
CASE 505AD
PIN ASSIGNMENT
VSS
NC
SCL
1
6
2
5
3
4
VDD
INT
SDA
(Top View)
ORDERING INFORMATION
Device
Package
Shipping†
NOA1305CUTAG
CUDFN6
(Pb−Free)
2500 / Tape &
Reel
Temperature Range
−40°C to 85°C
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
Applications
• Saves Display Power In Applications Such As:
♦
♦
♦
Cell Phones, PDAs, MP3 Players, GPS
Cameras, Video Recorders
Mobile Devices with Displays or Backlit Keypads
© Semiconductor Components Industries, LLC, 2012
October, 2012 − Rev. 0
1
Publication Order Number:
NOA1305/D
NOA1305
Vin = 2.0 to 3.6 V
R1
1k
hn
6
VDD
R2
1k
R3
1k
MCU
4
SDA
3
SCL
5
INT
SDA
SCL
INT
C2 1
VSS
10 m
IC1
NOA1305
C1
10 m
Cb not to exceed 400 pF including
all parasitic capacitances
Figure 1. Typical Application Circuit
2C Interface
II2C
Interface
&
Control
Control
ADC
hn
Reference
Diode
Photo
Diode
SDA
SCL
INT
Osc
Figure 2. Simplified Block Diagram
Table 1. PIN FUNCTION DESCRIPTION
Pin
Pin Name
1
VSS
Ground pin.
Description
2
NC
No connection.
3
SCL
External I2C clock supplied by the I2C master. Requires a 1 kW pull−up resistor.
4
SDA
Bi−directional data signal for communications between this device and the I2C master. Requires a 1 kW
pull−up resistor.
5
INT
Interrupt request to the host. Programmable active state, open−drain output and requires an external
1 kW pull−up resistor.
6
VDD
Power pin.
Table 2. ABSOLUTE MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Input power supply
VDD
4.0
V
Input voltage range
Vin
−0.3 to VDD + 0.2
V
Output voltage range
Vout
−0.3 to VDD + 0.2
V
TJ(max)
85
°C
TSTG
−40 to 85
°C
ESD Capability, Human Body Model (Note 1)
ESDHBM
2
kV
ESD Capability, Charged Device Model (Note 1)
ESDCDM
750 (corner pins), 500 (center pins)
V
ESD Capability, Machine Model (Note 1)
ESDMM
200
V
Moisture Sensitivity Level
MSL
5
−
Lead Temperature Soldering (Note 2)
TSLD
260
°C
Maximum Junction Temperature
Storage Temperature
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. This device incorporates ESD protection and is tested by the following methods:
ESD Human Body Model tested per EIA/JESD22−A114
ESD Charged Device Model tested per ESD−STM5.3.1−1999
ESD Machine Model tested per EIA/JESD22−A115
Latchup Current Maximum Rating: ≤ 100 mA per JEDEC standard: JESD78
2. For information, please refer to our Soldering and Mounting Techniques Reference Manual, SOLDERRM/D
http://onsemi.com
2
NOA1305
Table 3. OPERATING RANGES
Standard Mode
Fast Mode
Symbol
Min
Max
Min
Max
Unit
Power supply voltage
VDD
2.4
3.6
2.4
3.6
V
Power supply current
IDD
120
mA
Rating
Quiescent supply current (Note 3)
120
2.0
mA
Low level input voltage (VDD related input levels)
IDD_qe
VIL
−0.5
0.3 VDD
2.0
−0.5
0.3 VDD
V
High level input voltage (VDD related input levels) (Note 4)
VIH
0.7 VDD
VDD + 0.5
0.7 VDD
VDD + 0.5
V
Hysteresis of Schmitt trigger inputs (VDD > 2 V)
Vhys
N/A
N/A
0.05 VDD
−
V
Low level output voltage (open drain) at 3 mA sink current
(VDD > 2 V)
VOL
0
0.4
0
0.4
V
Output low current (VOl=0.4 V)
IOL
3
N/A
3
N/A
mA
Output low current (VOl=0.6 V)
IOL
N/A
N/A
6
N/A
mA
Output fall time from VIHmin to VILmax with a bus capacitance, Cb from 10 pF to 400 pF (Note 4)
tof
−
250
20+0.1Cb
250
ns
Pulse width of spikes which must be suppressed by the
input filter
tSP
N/A
N/A
0
50
ns
Input current of IO pin with an input voltage between 0.1
VDD and 0.9 VDD
II
−10
10
−10
10
mA
Capacitance on IO pin
CI
−
10
−
10
pF
Operating free−air temperature range
TA
−40
85
−40
85
°C
3. Current dissipation when a software Power Down command is sent to the device.
4. Cb = capacitance of one bus line, maximum value of which including all parasitic capacitances should be less than 400 pF.
Table 4. ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over VDD = 3.3 V, −40°C < TA < 85°C) (Note 5)
Standard Mode
Fast Mode
Symbol
Min
Max
Min
Max
Unit
fSCL
0
100
0
400
kHz
tHD;STA
4.0
−
0.6
−
mS
Low period of SCL clock
tLOW
4.7
1.3
mS
High period of SCL clock
tHIGH
4.0
0.6
mS
Parameter
SCL clock frequency
Hold time for START condition. After this period, the first
clock pulse is generated.
Set−up time for a repeated START condition
tSU;STA
4.7
−
0.6
−
mS
tHD;DAT_d
0
3.45
0
0.9
mS
tSU;DAT
250
−
100
−
nS
Rise time of both SDA and SCL (Note 6)
tr
−
1000
20 + 0.1Cb
300
nS
Fall time of both SDA and SCL (Note 6)
tf
−
300
20 + 0.1Cb
300
nS
tSU;STO
4.0
−
0.6
−
mS
Data hold time for I2C−bus devices
Data set−up time
Set−up time for STOP condition
Bus free time between STOP and START condition
tBUF
4.7
−
1.3
−
mS
Capacitive load for each bus line
Cb
−
400
−
400
pF
Noise margin at the low level for each connected device
(including hysteresis)
VnL
0.1 VDD
−
0.1 VDD
−
V
Noise margin at the high level for each connected device
(including hysteresis)
VnH
0.2 VDD
−
0.2 VDD
−
V
Parameter
Symbol
Typ
Typ
Unit
fosc
1
1
MHz
Internal Oscillator Frequency
5. Refer to Figure 3 for more information on AC characteristics
6. The rise time and fall time are measured with a pull−up resistor Rp = 1 kW and Cb of 400 pF (including all parasitic capacitances).
http://onsemi.com
3
NOA1305
Table 5. OPTICAL CHARACTERISTICS
(Unless otherwise specified, these specifications are for VDD = 3.3 V, TA = 25°C, TINT = 200 ms)
Parameter
Irradiance responsivity
Illuminance responsivity
Dark responsivity
Test Conditions
Symbol
Min
Typ
Max
Unit
Re
545
nM
White LED Source:
Ev = 100 lux (see Figure 6)
Rvi100
154
Counts
White LED source:
Ev = 1000 lux (see Figure 6)
Rvi1000
1543
Ev = 0 lux (see Figure 6)
IDARK
0
lp (see Figure 5)
Figure 3. AC Characteristics
http://onsemi.com
4
Counts
NOA1305
TYPICAL CHARACTERISTICS
ALS
Human Eye
0.9
Fluorescent
(5000K)
0.8
0.7
White LED
(5600K)
0.6
0.5
Fluorescent
(2700K)
0.4
0.3
0.2
Incandescent
(2850K)
200 300
400
500
600
700
800
900
1.5
2.0
Figure 4. Spectral Response
Figure 5. Illumination Response to Various
Light Sources
OUTPUT COUNTS (Normalized to 20°C)
1600
1200
800
400
200
400
600
800
1000
1200
1.2
1.0
0.8
0.6
0.4
VDD = 3.3 V
0.2
0
−60
−40
−20
0
20
40
60
80
Ev (lux)
TEMPERATURE (°C)
Figure 6. Output Counts vs. Ev
Figure 7. Output Counts vs. Temperature
(100 lux)
−50
−60
−70
−80
−90
10
20
30
−30
−40
−50
40
50
60
−60
70
−100
−140
−150
−160
130
140
−170 180 170
160
0.6
50
60
70
0.2
80
90
−90
0.0
90
100
−100
Q
−110
o
−90
150
1
6
2
5
3
120
−130
o
90
−140
−150
150
−160
160
−170 180 170
4
TOP VIEW
Figure 8. Output Counts vs. Angle
(End View, Normalized)
Q
110
−120
END VIEW
130
140
SIDE VIEW
o
−90
TOP VIEW
Figure 9. Output Counts vs. Angle
(Side View, Normalized)
http://onsemi.com
5
100
40
−80
120
−130
30
80
110
−120
0.8
10 20
0.4
−70
100
−110
−10 0
−20 1.0
4
−40
0
−10
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
5
−20
3
−30
6
OUTPUT COUNTS
1.0
RATIO
White LED (5600K)
0
0.5
WAVELENGTH (nm)
2000
0
0
1000
2
0.1
0
1
OUTPUT COUNTS (Normalized)
1.0
90o
NOA1305
2.0
1.2
OUTPUT COUNTS (Normalized)
1.5
1.0
0.5
0
−0.5
VDD = 3.3 V
−1.0
−1.5
−2.0
−60
−40
−20
0
20
40
60
80
0.8
0.6
0.4
0.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
TEMPERATURE (°C)
VDD (V)
Figure 10. Output Counts vs. Temperature
(0 lux)
Figure 11. Output Counts vs. Supply Voltage
(100 lux)
100
100
90
90
80
80
70
70
60
60
50
40
50
40
30
30
20
20
VDD = 3.3 V
10
0
−60
−40
−20
0
20
40
60
80
10
0
100
2.4
2.6
2.8
3.0
3.2
3.4
3.6
TEMPERATURE (°C)
VDD (V)
Figure 12. Supply Current vs. Temperature
(100 lux)
Figure 13. Supply Current vs Supply Voltage
(100 lux)
4
7.5
6.0
RP(max) (KW)
1.0
0
100
IDD (mA)
IDD (mA)
OUTPUT COUNTS (Normalized to 20°C)
TYPICAL CHARACTERISTICS
RP = 1 kW
Cb = 400 pF (including all parasitic caps)
tf = 75 ns
3
4.5
2
3.0
RS = 0
1.5
0
0
100
200
1
300
0
400
126.0u
126.5u
127.0u
BUS CAPACITANCE (pF)
TIME (s)
Figure 14. Maximum Value of RP (in kW) as a
function of Bus Capacitance (in pF)
Figure 15. SDA Fall Time (tf)
http://onsemi.com
6
127.5u
NOA1305
DESCRIPTION OF OPERATION
Ambient Light Sensor Architecture
In the interrupt driven mode, once the NOA1305 is
configured, no I2C activity is necessary until the ambient
light intensity goes above the value programmed in the
interrupt threshold register. When this occurs, the device
signals an interrupt on the INT pin. Then it is up to the I2C
master host to read the ALS count from the device.
In polling mode, interrupts are typically disabled, but the
NOA1305 continuously takes measurements and the I2C
master host reads out the most recent count whenever it
desires to do so, typically in a timed repeat loop.
In power−down mode, the NOA1305 stops taking
ambient light measurements and powers down most of the
internal circuitry and the INT pin is deactivated. Power is
maintained to preserve the register values (static memory)
and a portion of the I2C remains active to monitor for a
power−on command to the NOA1305.
The NOA1305 employs a sensitive photo diode fabricated
in ON Semiconductor’s standard CMOS process
technology. The major components of this sensor are as
shown in Figure 2. The photons which are to be detected pass
through an ON Semiconductor proprietary color filter
limiting extraneous photons and thus performing as a band
pass filter on the incident wave front. The filter only
transmits photons in the visible spectrum which are
primarily detected by the human eye. The photo response of
this sensor is as shown in Figure 5.
The ambient light signal detected by the photo diode is
converted to digital signal using a variable slope integrating
ADC with a resolution of 16−bits, unsigned. The ADC value
is provided to the control block connected to the I2C
interface block.
Equation 1 shows the relationship of output counts Cnt as
a function of integration constant Ik, integration time Tint (in
seconds) and the intensity of the ambient light, IL(in lux), at
room temperature (25°C).
I L + C ntń(I k
T int )
I2C Interface
The NOA1305 acts as an I2C slave device and supports
single register read and write operations, in addition to block
read and block write operations. All data transactions on the
bus are 8 bits long. Each data byte transmitted is followed by
an acknowledge bit. Data is transmitted with the MSB first.
Figure 16 shows an I2C write operation. Write transactions
begin with the master sending an I2C start sequence
followed by the seven bit slave address (NOA1305 = 0x39)
and the write(0) command bit. The NOA1305 will
acknowledge this byte transfer with an appropriate ACK.
Next the master will send the 8 bit register address to be
written to. Again the NOA1305 will acknowledge reception
with an ACK. Finally, the master will begin sending 8 bit
data segment(s) to be written to the NOA1305 register bank.
The NOA1305 will send an ACK after each byte and
increment the address pointer by one in preparation for the
next transfer. Write transactions are terminated with either
an I2C STOP or with another I I2C START (repeated
START).
(eq. 1)
Where:
Ik ≈ 7.7 (for White LED Source)
For example let:
Cnt = 1000
Tint = 200 mS
Intensity of ambient light, IL(in lux):
I L + 1000ń(7.7
200 mS )
(eq. 2)
IL = 649 lux
Modes of Operation
The NOA1305 can be placed in any of the following
modes of operation by programming registers over the I2C
bus:
1. Interrupt driven mode
2. Polling mode
3. Power−down mode
Device
Address
A[6:0] WRITE ACK
011 1001 0
0x72
0
Register
Address
D[7:0] ACK
0000 0110 0
7
Start
Condition
8
Figure 16.
I2C
Register
Data
D[7:0] ACK
00000000 0
8
Write Command
http://onsemi.com
7
Stop
Condition
NOA1305
Figure 17 shows the most basic I2C read command
sequence sent by the master to the slave device. The
sequence consists of a complete I2C write command which
sets the address pointer in preparation for the I2C read
command since the read command itself does not include a
Device
Address
A[6:0] WRITE ACK
011 1001 0
0x72
0
register address. When reading from a read only data register
in the NOA1305 it is acceptable to write a 0 to the register
in order to update the address pointer, but the 0 does not
actually over−write the value in the data register.
Register
Address
D[7:0] ACK
0000 0110 0
7
Register
Data
D[7:0] ACK
00000000 0
8
8
Stop
Condition
Start
Condition
Device
Address
Register
Data [A]
A[6:0] READ
011 1001 1
0x73
Register
Data [A+1]
D[7:0] NACK
ACK
D[7:0] ACK
0
bbbbbbbb 0
bbbbbbbb 1
7
8
8
Stop
Condition
Start
Condition
Figure 17. I2C Read Command
Once the I2C write command is completed, the master
sends an I2C start sequence followed by the seven bit slave
address (NOA1305 = 0x39) and the read (1) command bit.
The NOA1305 will acknowledge this byte transfer with an
appropriate ACK. The NOA1305 will then begin shifting
out data from the register just addressed. If the master wishes
to receive more data (next register address), it will ACK the
slave at the end of the 8 bit data transmission, and the slave
will respond by sending the next byte, and so on. To signal
the end of the read transaction, the master will send a NACK
bit at the end of a transmission followed by an I2C STOP.
LED
Rise and Fall Time of SDA (Output)
Proper operation of the I2C bus depends on keeping the
bus capacitance low and selecting suitable pull−up resistor
values. Figure 15 shows the fall time on SDA in output mode
under maximum load conditions. The measurement set−up
is shown in Figure 18. Figure 14 shows the maximum value
of the pull−up resistor (RP) as a function of the I2C data bus
capacitance.
ADC
ADC
hn
16−bits
Control
Pulse
Generator
I2C Serial
Interface
NOA1305
Figure 18. Measurement Set−up
http://onsemi.com
8
INT
SCL
SDA
NOA1305
NOA1305 Data Registers
NOA1305 operation is observed and controlled by internal data registers read from and written to via the external I2C
interface. Registers are listed in Table 6. Default values are set on initial power up.
Table 6. NOA1305 DATA REGISTERS (Note 7)
Address
Register
Type
Value (binary)
Description
0x00
POWER_CONTROL
RW
0000 0000
Power Down
0000 1000
Power On
0000 1001
Test Mode 1 (reserved)
0000 1010
Test Mode 2 (fixed output 0x5555)
Default (binary)
0000 1000
0000 1011
Test Mode 3 (fixed output 0xAAAA)
0x01
RESET
RW
0001 0000
Reset ALS data. Resets to 0000
0000 0000
0x02
INTEGRATION_TIME
RW
0000 0000
800 ms continuous measurement
0000 0010
0000 0001
400 ms continuous measurement
0000 0010
200 ms continuous measurement
0000 0011
100 ms continuous measurement
0000 0100
50 ms continuous measurement
0000 0101
25 ms continuous measurement
0000 0110
12.5 ms continuous measurement
0000 0111
6.25 ms continuous measurement
0000 0001
L→H
0000 0010
H→L
0000 0011
Inactive, always H
0x03
INT_SELECT
RW
0000 0011
0x04
INT_THRESH_LSB
RW
XXXX XXXX
Interrupt threshold, least significant bits
0000 0000
0x05
INT_THRESH_MSB
RW
XXXX XXXX
Interrupt threshold, most significant bits
0000 1000
0x06
ALS_DATA_LSB
R
XXXX XXXX
ALS measurement data, least significant bits
0000 0000
0x07
ALS_DATA_MSB
R
XXXX XXXX
ALS measurement data, most significant bits
0000 0000
0x08
DEVICE_ID_LSB
R
0001 1001
Device ID value, least significant bits
(1305 decimal, 0x0519 hex)
0001 1001
0x09
DEVICE_ID_MSB
R
0000 0101
Device ID value, most significant bits
(1305 decimal, 0x0519 hex)
0000 0101
7. Writing a value other than those specified for registers 0x00, 0x01, 0x02, 0x03 will cause the specified default value to be written instead.
http://onsemi.com
9
NOA1305
POWER_CONTROL Register (0x00)
INTEGRATION_TIME Register (0x02)
The POWER_CONTROL register is used to power the
device up and down via software control. By default this
device powers up in the power ON mode. To reduce power
consumption, the NOA1305 can be powered down at any
time by writing 0x00 to this register.
To power up the device, use the following write command
sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x00 for the POWER_CONTROL register
address
4. Issue 0x08 to put the device in the power on state
5. Issue Stop command
After applying power to the device or after issuing a
power−on command, stable ALS_DATA and INT signal
may not be available for the first three integration times. For
example with a default of 200 ms integration time, the I2C
master should wait at least 600 ms before accessing this
device.
To power down the device, use the following write
command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x00 for the POWER_CONTROL register
address
4. Issue 0x00 to put the device in the power down
state
5. Issue Stop command
After issuing a power−on command, the I2C master
should wait at least 1.5 ms before accessing this device.
The data registers are set to their default values when
power is first applied to the device. However the
power−down and power−on commands do not affect the
values of the data registers.
The test modes provide a useful debugging mode as they
cause the device to output known values in place of the
ALS_DATA values.
The INTEGRATION_TIME register controls the
integration time of the ambient light sensor which directly
affects the sensitivity.
To set the integration time, use the following write
command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x02 for the INTEGRATION_TIME register
address
4. Issue 0x02 to set the integration time to 200 ms
(for example)
5. Issue Stop command
INT_SELECT Register (0x03)
The INT_SELECT register controls the polarity of the
interrupt pin INT and enables or disables interrupts on that
pin.
To specify low to high transitions on INT to signal an
interrupt, use the following write command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x03 for the INT_SELECT register address
4. Issue 0x01 to specify low to high signaling on INT
5. Issue Stop command
To specify low to high transitions on INT to signal an
interrupt, use the following write command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x03 for the INT_SELECT register address
4. Issue 0x02 to specify high to low signaling on INT
5. Issue Stop command
Disabling interrupts causes the INT pin to be held in the
open−drain or high state. To disable interrupts completely on
the INT pin, use the following write command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x03 for the INT_SELECT register address
4. Issue 0x03 to disable interrupts on INT
5. Issue Stop command
RESET Register (0x01)
Software reset is controlled by this register. Setting this
register followed by an I2C_STOP sequence will
immediately reset the NOA1305 to the startup standby state
and clear the ALS_DATA register. However the values of
the other data registers are not affected.
To reset the device, use the following write command
sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x01 for the RESET register address
4. Issue 0x10 to reset the device
5. Issue Stop command
After issuing a reset command, the device will reset the
RESET register to 0x00.
INT_THRESH_LSB and INT_THRES_MSB Registers
(0x04, 0x05)
The INT_THRESH register specifies an ambient light
threshold value for signaling interrupts on the INT pin. The
INT_THRESH register is 16−bits wide to match the 16−bit
ALS_DATA register and is accessed over the I2C bus as two
8−bit registers for the least and most significant bits (LSB
and MSB). On any measurement cycle where the
ALS_DATA intensity count exceeds the INT_THRESH
value, the INT pin will become active and will remain active
until a measurement cycle where the count is less than or
http://onsemi.com
10
NOA1305
To read the ALS_DATA register, use the following read
command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x06 for the INT_DATA_LSB register
address
4. Issue Start command
5. Issue 0x73 (lower seven bits of I2C slave address
0x39 followed by read−bit 1)
6. Read the ALS_DATA_LSB byte
7. Read the ALS_DATA_MSB byte
8. Issue Stop command
equal to the threshold (and provided the INT pin is enabled,
see INT_SELECT register).
Changing the INT_THRESH register value can cause the
INT pin to change immediately if the ALS_DATA to
INT_THRESH comparison changes.
Powering down the device will cause the INT pin to
become inactive.
To program a value into the INT_THRESH register, use
the following write command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x04 for the INT_THRES_LSB register
address
4. Issue the 8−bit LSB value
5. Issue Stop command
6. Issue Start command
7. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
8. Issue 0x05 for the INT_THRES_MSB register
address
9. Issue the 8−bit MSB value
10. Issue Stop command
After a power−down and power−on sequence, wait at least
three integration times for the data to stabilize, before
accessing any ALS_DATA values from NOA1305.
DEVICE_ID_LSB and DEVICE_ID_MSB Registers
(0x08, 0x09)
The DEVICE_ID register is a pre−programmed register
that describes the device. For the NOA1305, the register
holds the decimal value of 1305 (0x0519). The DEVICE_ID
register is 16−bits wide and is accessed from the I2C bus as
two 8−bit registers for the least and most significant bits
(LSB and MSB).
To read the DEVICE_ID register, use the following read
command sequence:
1. Issue Start command
2. Issue 0x72 (lower seven bits of I2C slave address
0x39 followed by write−bit 0)
3. Issue 0x08 for the DEVICE_ID_LSB register
address
4. Issue Start command
5. Issue 0x73 (lower seven bits of I2C slave address
0x39 followed by read−bit 1)
6. Read the DEVICE_ID_LSB byte
7. Read the DEVICE_ID_MSB byte
8. Issue Stop command
ALS_DATA_LSB and ALS_DATA_MSB Registers
(0x06, 0x07)
The ALS_DATA register holds the ambient light intensity
count from the most recent measurement. The ALS_DATA
register is 16−bits wide and is accessed from the I2C bus as
two 8−bit registers for the least and most significant bits
(LSB and MSB).
http://onsemi.com
11
NOA1305
Example Programming Sequence
The following pseudo code configures the NOA1305 ambient light sensor and then runs it in an interrupt driven mode. When
the controller receives an interrupt, it reads the ALS_Data from the device, sets a flag and then waits for the main polling loop
to respond to the ambient light change.
external subroutine I2C_Read_Byte (I2C_Address, Data_Address);
external subroutine I2C_Read_Block (I2C_Address, Data_Start_Address, Count, Memory_Map);
external subroutine I2C_Write_Byte (I2C_Address, Data_Address, Data);
external subroutine I2C_Write_Block (I2C_Address, Data_Start_Address, Count, Memory_Map);
subroutine Initialize_ALS () {
MemBuf[0x00] = 0x08;
// POWER_CONTROL assert Power On
MemBuf[0x01] = 0x10;
// RESET assert reset
MemBuf[0x02] = 0x02;
// INTEGRATION_TIME select 200ms
MemBuf[0x03] = 0x01;
// INT_SELECT select Low to High
MemBuf[0x04] = 0xFF;
// INT_THRESH_LSB
MemBuf[0x05] = 0x8F;
// INT_THRESH_MSB
I2C_Write_Block (I2CAddr, 0x00, 6, MemBuf);
}
subroutine I2C_Interupt_Handler () {
// Retrieve and store the ALS data
ALS_Data_LSB = I2C_Read_Byte (I2CAddr, 0x06);
ALS_Data_MSB = I2C_Read_Byte (I2CAddr, 0x07);
NewALS = 0x01;
}
subroutine main_loop () {
I2CAddr = 0x39;
NewALS = 0x00;
Initialize_ALS ();
loop {
// Do some other polling operations
if (NewALS == 0x01) {
NewALS = 0x00;
// Do some operations with ALS_Data
}
}
}
http://onsemi.com
12
NOA1305
PACKAGE DIMENSIONS
CUDFN6, 2x2
CASE 505AD−01
ISSUE B
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. DIMENSION b APPLIES TO PLATED TERMINAL AND
IS MEASURED BETWEEN 0.15 AND 0.30mm FROM
THE TERMINAL TIP.
4. COPLANARITY APPLIES TO THE EXPOSED PAD AS
WELL AS THE TERMINALS.
0.10 C
2X
D
A B
2X
PIN ONE
REFERENCE
ÍÍÍ
ÍÍÍ
ÍÍÍ
d
E
A
DIM
A
A1
A3
b
D
D2
d
E
E2
e
K
L
q
A1
DETAIL A
TOP VIEW
DETAIL A
0.05 C
7X
q
0.10 C
A3
0.05 C
NOTE 4
C
SIDE VIEW
SEATING
PLANE
END VIEW
MOUNTING FOOTPRINT
0.10 C A
6X
MILLIMETERS
MAX
MIN
0.55
0.65
0.00
0.05
0.20 REF
0.18
0.28
2.00 BSC
1.50
1.70
--0.10
2.00 BSC
1.00
0.80
0.65 BSC
0.20
--0.25
0.35
10 5
45
6X
1.70
B
0.52
D2
L
1
3
1.00
E2
0.10 C A
6
K
4
e
6X
B
1
b
0.10 C A
BOTTOM VIEW
2.30
0.05 C
B
0.65
PITCH
NOTE 3
6X
0.28
DIMENSIONS: MILLIMETERS
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks,
copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. SCILLC
reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any
particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without
limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications
and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC
does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for
surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where
personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and
its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly,
any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture
of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada
Email: [email protected]
N. American Technical Support: 800−282−9855 Toll Free
USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
Japan Customer Focus Center
Phone: 81−3−5817−1050
http://onsemi.com
13
ON Semiconductor Website: www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
For additional information, please contact your local
Sales Representative
NOA1305/D