AD7814ART-REEL7 Analog Devices Inc, AD7814ART-REEL7 Datasheet - Page 7

• Manufacturer Part Number: AD7814ART-REEL7
• Description: IC TEMP SNSR 10BIT DGTL SOT-23-6
• Manufacturer: Analog Devices Inc

Specifications of AD7814ART-REEL7

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Register Bank
• Sensor Type: Internal
• Sensing Temperature: -55°C ~ 125°C
• Output Type: MICROWIRE™, QSPI™, SPI™
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: AD7814ART-REEL7; AD7814ART-REEL7TR

AD7814 to PIC16C6x/7x Interface
Figure 5 shows an interface circuit between the AD7814 and the
PIC16C6x/7x microcontroller. The PIC16C6x/7x synchronous
serial port (SSP) is configured as an SPI master with the clock
polarity bit set to a logic one. In this mode, the serial clock line
of the PIC16C6x/7x idles high between data transfers. Data is
transferred to and from the AD7814 in two 8-bit serial data
operations. In the example shown, port line RA1 is being used
to generate the CS for the AD7814.
AD7814 to ADSP-21xx Interface
Figure 6 shows an interface between the AD7814 and the
ADSP-21xx DSP processor. To ensure correct operation of the
interface, the SPORT control register should be set up as follows:
The interface requires an inverter between the SCLK line of the
ADSP-21xx and the SCLK input of the AD7814. 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 earlier.
REV. E
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
Figure 5. AD7814 to PIC16C6x/7x Interface
Figure 4. AD7814 to 8051 Interface
*ADDITIONAL PINS OMITTED FOR CLARITY
*ADDITIONAL PINS OMITTED FOR CLARITY
AD7814*
AD7814*
DOUT
DOUT
SCLK
SCLK
DIN
DIN
CS
CS
PIC16C6x/7x*
P3.1
P3.0
P1.2
P1.3
SCK
SDO
SDI
RA1
8051*
–7–
MOUNTING THE AD7814
The AD7814 can be used for surface or air temperature sensing
applications. If the device is cemented to a surface with ther-
mally conductive adhesive, the die temperature will be within
about 0.1°C of the surface temperature, thanks to the device’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, so the
temperature of the die will be 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 AD7814 and its associated wiring and cir-
cuits 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
AD7814 package allows it to be mounted inside sealed metal
probes, which provide a safe environment for the device.
SUPPLY DECOUPLING
The AD7814 should be decoupled with a 0.1 µF ceramic
capacitor between V
if the AD7814 is mounted remotely from the power supply.
–0.2
–0.4
1.0
0.8
0.6
0.4
0.2
0
Figure 6. AD7814 to ADSP-21xx Interface
–55
Figure 7. Typical Temperature Error
*ADDITIONAL PINS OMITTED FOR CLARITY
AD7814*
–40
DOUT
SCLK
DD
DIN
CS
and GND. This is particularly important
0
TEMPERATURE – C
25
40
ADSP-21xx*
SCK
DR
DT
RFS
TFS
85
AD7814
100
120