ADT7320UCPZ AD [Analog Devices], ADT7320UCPZ Datasheet - Page 12

• Manufacturer Part Number: ADT7320UCPZ
• Manufacturer: AD [Analog Devices]

ADT7320
CONTINUOUS READ MODE
When the command byte = 01010100 (0x54), the contents of
the temperature value register can be read out without requiring
repeated writes to the communications register. By sending 16
SCLK clocks to the ADT7320, the contents of the temperature
value register are output onto the DOUT pin.
To exit the continuous read mode, the command byte 01010000
(0x50) must be written to the ADT7320.
While in continuous read mode, the part monitors activity
on the DIN line so that it can receive the instruction to exit
the continuous read mode. Additionally, a reset occurs if 32
consecutive 1s are seen on the DIN pin. Therefore, hold DIN
low in continuous read mode until an instruction is to be
written to the device.
In continuous read mode, the temperature value register cannot
be read when a conversion is taking place. If an attempt is made
to read the temperature value register while a conversion is taking
place, then all 0s are read. This is because the continuous read
mode blocks read access to the temperature value register during a
conversion.
DOUT
SCLK
DIN
CS
0x54
TEMPERATURE
VALUE
Figure 14. Continuous Read Mode
Rev. PrA | Page 12 of 24
TEMPERATURE
SHUTDOWN
The ADT7320 can be placed in shutdown mode by writing 1
to Bit 5 and 1 to Bit 6 of the configuration register (Register
Address 0x01). The ADT7320 can be taken out of shutdown
mode by writing 0 to Bit 5 and 0 to Bit 6 of the configuration
register (Register Address 0x01). The ADT7320 typically takes
1 ms (with a 0.1 μF decoupling capacitor) to come out of shut-
down mode. The conversion result from the last conversion
prior to shutdown can still be read from the ADT7320 even
when it is in shutdown mode. When the part is taken out of
shutdown mode, the internal clock starts and a conversion initiates.
FAULT QUEUE
Bit 0 and Bit 1 of the configuration register (Register Address 0x01)
are used to set up a fault queue. Up to four faults are provided to
prevent false tripping of the INT and CT pins when the ADT7320
is used in a noisy temperature environment. The number of
faults set in the queue must occur consecutively to set the INT
and CT outputs. For example, if the number of faults set in the
queue is four, then four consecutive temperature conversions
must occur, with each result exceeding a temperature limit in
any of the limit registers, before the INT and CT pins are activated.
If two consecutive temperature conversions exceed a temperature
limit and the third conversion does not, the fault count is reset to 0.
VALUE
Preliminary Technical Data
TEMPERATURE
VALUE