ADXL346ACCZ Analog Devices Inc, ADXL346ACCZ Datasheet - Page 25

• Manufacturer Part Number: ADXL346ACCZ
• Description: 76R7595
• Manufacturer: Analog Devices Inc

Specifications of ADXL346ACCZ

• Acceleration Range: ± 2g, ± 4g, ± 8g, ± 16g
• No. Of Axes: 3
• Sensor Case Style: LGA
• No. Of Pins: 16
• Supply Voltage Range: 1.7V To 2.75V
• Operating Temperature Range: -40°C To +85°C

When clearing the link bit, it is recommended that the part be
placed into standby mode and then set back to measurement
mode with a subsequent write. This is done to ensure that the
device is properly biased if sleep mode is manually disabled;
otherwise, the first few samples of data after the link bit is cleared
may have additional noise, especially if the device was asleep
when the bit was cleared.
AUTO_SLEEP Bit
If the link bit is set, a setting of 1 in the AUTO_SLEEP bit enables
the autosleep functionality. In this mode, the ADXL346 auto-
matically switches to sleep mode if the inactivity function is
enabled and inactivity is detected (that is, when acceleration is
below the THRESH_INACT value for at least the time indicated
by TIME_INACT). If activity is also enabled, the ADXL346
automatically wakes up from sleep after detecting activity and
returns to operation at the output data rate set in the BW_RATE
register. A setting of 0 in the AUTO_SLEEP bit disables automatic
switching to sleep mode. See the description of the sleep bit in this
section for more information on sleep mode.
If the link bit is not set, the AUTO_SLEEP feature is disabled,
and setting the AUTO_SLEEP bit does not have any impact on
device operation. Refer to the Link Bit section or the Link Mode
section for more information about using the link feature.
When clearing the AUTO_SLEEP bit, it is recommended that the
part be placed into standby mode and then set back to measure-
ment mode with a subsequent write. This is done to ensure that
the device is properly biased if sleep mode is manually disabled;
otherwise, the first few samples of data after the AUTO_SLEEP
bit is cleared may have additional noise, especially if the device
was asleep when the bit was cleared.
Measure Bit
A setting of 0 in the measure bit places the part into standby mode,
and a setting of 1 places the part into measurement mode. The
ADXL346 powers up in standby mode with minimum power
consumption.
Sleep Bit
A setting of 0 in the sleep bit puts the part into the normal mode
of operation, and a setting of 1 places the part into sleep mode.
Sleep mode suppresses DATA_READY, stops transmission of data
to FIFO, and switches the sampling rate to one specified by the
wakeup bits. In sleep mode, only the activity function can be used.
While the DATA_READY interrupt is suppressed, the output
data registers are still updated at the sampling rate set by the
wakeup bits.
When clearing the sleep bit, it is recommended that the part be
placed into standby mode and then set back to measurement
mode with a subsequent write. This is done to ensure that the
device is properly biased if sleep mode is manually disabled;
otherwise, the first few samples of data after the sleep bit is
cleared may have additional noise, especially if the device was
asleep when the bit was cleared.
Rev. A | Page 25 of 40
Wakeup Bits
These bits control the frequency of readings in sleep mode as
described in Table 20.
Table 20. Frequency of Readings in Sleep Mode
D1
0
0
1
1
Register 0x2E—INT_ENABLE (Read/Write)
D7
DATA_READY
D3
Inactivity
Setting bits in this register to a value of 1 enables their respective
functions to generate interrupts, whereas a value of 0 prevents
the functions from generating interrupts. The DATA_READY,
watermark, and overrun/orientation bits enable only the interrupt
output; the functions are always enabled. It is recommended that
interrupts be configured before enabling their outputs.
Register 0x2F—INT_MAP (Read/Write)
D7
DATA_READY
D3
Inactivity
Bits set to 0 in this register send their respective interrupts to the
INT1 pin, whereas bits set to 1 send their respective interrupts to
the INT2 pin. All selected interrupts for a given pin are OR’ e d.
Register 0x30—INT_SOURCE (Read Only)
D7
DATA_READY
D3
Inactivity
Bits set to 1 in this register indicate that their respective functions
have triggered an event, whereas bits set to 0 indicate that the
corresponding events have not occurred. The DATA_READY,
watermark, and overrun/orientation bits are always set if the
corresponding events occur, regardless of the INT_ENABLE
register settings, and are cleared by reading data from the
DATAX, DATAY, and DATAZ registers. The DATA_READY and
watermark bits may require multiple reads, as indicated in the
FIFO mode descriptions in the FIFO section. Other bits, and the
corresponding interrupts, including orientation if enabled, are
cleared by reading the INT_SOURCE register.
Setting
D0
0
1
0
1
D6
SINGLE_TAP
D2
FREE_FALL
D6
SINGLE_TAP
D2
FREE_FALL
D6
SINGLE_TAP
D2
FREE_FALL
D5
DOUBLE_TAP
D1
Watermark
D5
DOUBLE_TAP
D1
Watermark
D5
DOUBLE_TAP
D1
Watermark
Frequency (Hz)
8
4
2
1
ADXL346
D4
Activity
D0
Overrun/
orientation
D4
Activity
D0
Overrun/
orientation
D4
Activity
D0
Overrun/
orientation