ADT7320UCPZ AD [Analog Devices], ADT7320UCPZ Datasheet - Page 13

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

Preliminary Technical Data
TEMPERATURE DATA FORMAT
One LSB of the ADC corresponds to 0.0625°C in 13-bit mode.
The ADC can theoretically measure a temperature range of 255°C,
but the ADT7320 is guaranteed to measure a low value temperature
limit of −40°C to a high value temperature limit of +150°C. The
temperature measurement result is stored in the 16-bit temperature
value register and is compared with the high temperature limits
stored in the T
is also compared with the low temperature limit stored in the T
setpoint register.
Temperature data in the temperature value register, the T
setpoint register, the T
setpoint register are represented by a 13-bit, twos complement
word. The MSB is the temperature sign bit. The three LSBs,
Bit 0 to Bit 2, on power-up, are not part of the temperature
conversion result and are flag bits for T
Table 5 shows the 13-bit temperature data format without
Bit 0 to Bit 2.
The number of bits in the temperature data-word can be extended
to 16 bits, twos complement by setting Bit 7 to 1 in the configuration
register (Register Address 0x01). When using a 16-bit temperature
data value, Bit 0 to Bit 2 are not used as flag bits and are instead
the LSB bits of the temperature value. The power-on default
setting has a 13-bit temperature data value.
Reading back the temperature from the temperature value register
requires a 2-byte read. Designers that use a 9-bit temperature
data format can still use the ADT7320 by ignoring the last four
LSBs of the 13-bit temperature value. These four LSBs are Bit 3
to Bit 6 in Table 5.
Table 5. 13-Bit Temperature Data Format
Temperature
−40°C
−25°C
−0.0625°C
0°C
+0.0625°C
+25°C
+105°C
+125°C
+150°C
CRIT
setpoint register and the T
Digital Output
(Binary) Bits[15:3]
1 1101 1000 0000
1 1110 0111 0000
1 1111 1111 1111
0 0000 0000 0000
0 0000 0000 0001
0 0001 1001 0000
0 0110 1001 0000
0 0111 1101 0000
0 1001 0110 0000
HIGH
setpoint register, and the T
CRIT
HIGH
, T
HIGH
setpoint register. It
Digital
Output (Hex)
0x1D80
0x1E70
0x1FFF
0x000
0x001
0x190
0x690
0x7D0
0x960
, and T
LOW
LOW
CRIT
.
Rev. PrA | Page 13 of 24
LOW
TEMPERATURE CONVERSION FORMULAS
16-Bit Temperature Data Format
where ADC Code uses all 16 bits of the data byte, including the
sign bit.
where the MSB is removed from the ADC code.
13-Bit Temperature Data Format
where ADC Code uses all 13 bits of the data byte, including the
sign bit.
where the MSB is removed from the ADC code.
10-Bit Temperature Data Format
where ADC Code uses all 10 bits of the data byte, including the
sign bit.
where the MSB is removed from the ADC Code.
9-Bit Temperature Data Format
where ADC Code uses all nine bits of the data byte, including
the sign bit.
where the MSB is removed from the ADC Code.
Positive Temperature = ADC Code(dec)/128
Negative Temperature = (ADC Code(dec) − 65,536)/128
Negative Temperature = (ADC Code(dec) − 32,768)/128
Positive Temperature = ADC Code(dec)/16
Negative Temperature = (ADC Code(dec) − 8192)/16
Negative Temperature = (ADC Code(dec) − 4096)/16
Positive Temperature = ADC Code(dec)/2
Negative Temperature = (ADC Code(dec) − 1024)/2
Negative Temperature = (ADC Code(dec) − 512)/2
Positive Temperature = ADC Code(dec)
Negative Temperature = ADC Code(dec) − 512
Negative Temperature = ADC Code(dec) − 256
ADT7320