ADT7302_05 AD [Analog Devices], ADT7302_05 Datasheet - Page 14

• Manufacturer Part Number: ADT7302_05
• Manufacturer: AD [Analog Devices]

ADT7302
ADT7302 to ADSP-21xx Interface
Figure 18 shows an interface between the ADT7302 and the
ADSP-21xx DSP processor. To ensure correct operation of the
interface, the SPORT control register should be set up as follows:
TFSW = RFSW = 1, alternate framing
INVRFS = INVTFS = 1, active low framing signal
DTYPE = 00, right justify data
SLEN = 1111, 16-bit data-words
ISCLK = 1, internal serial clock
TFSR = RFS = 1, frame every word
IRFS = 0, RFS configured as input
ITFS = 1, TFS configured as output
The interface requires an inverter between the SCLK line of the
ADSP-21xx and the SCLK input of the ADT7302. The ADSP-
21xx has the TFS and RFS of the SPORT tied together, with TFS
set as an output and RFS set as an input. The DSP operates in
alternate framing mode, and the SPORT control register is set
up as described previously.
*ADDITIONAL PINS OMITTED FOR CLARITY
ADT7302*
Figure 18. ADT7302 to ADSP-21xx Interface
DOUT
SCLK
DIN
CS
ADSP-21xx*
SCLK
DR
DT
RFS
TFS
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MOUNTING THE ADT7302
The ADT7302 can be used for surface- or air-temperature
sensing applications. If the device is cemented to a surface with
thermally conductive adhesive, the die temperature will be
within about 0.1°C of the surface temperature, because of the
ADT7302’s low power consumption. Care should be taken to
insulate the back and leads of the device from the air if the
ambient air temperature is different from the surface
temperature being measured.
The ground pin provides the best thermal path to the die,
therefore the temperature of the die is close to that of the
printed circuit ground track. Care should be taken to ensure
that this is in good thermal contact with the surface being
measured.
As with any IC, the ADT7302 and its associated wiring and
circuits must be kept free from moisture to prevent leakage and
corrosion, particularly in cold conditions where condensation is
more likely to occur. Water-resistant varnishes and conformal
coatings can be used for protection. The small size of the
ADT7302 allows it to be mounted inside sealed metal probes,
which provide a safe environment for the device.
SUPPLY DECOUPLING
The ADT7302 should be decoupled with a 0.1 μF ceramic
capacitor between V
if the ADT7302 is mounted remote from the power supply.
DD
and GND. This is particularly important