External Temperature Offset Register (Read/Write)
[Add. = 20h]
This register contains the offset value for the external temp-
erature channel. A twos complement number can be written to
this register, which is then added to the measured result before
it is stored or compared to limits. In this way, a one-point cali-
bration can be done whereby the whole transfer function of the
channel can be moved up or down. From a software point of
view, this may be a very simple method to vary the charac-
teristics of the measurement channel if the thermal charac-
teristics change. Because it is an 8-bit register, the temperature
resolution is 1°C.
Table 52. External Temperature Offset
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
0* 0* 0* 0* 0* 0* 0* 0*
*Default settings at power-up.
Internal Analog Temperature Offset Register
(Read/Write) [Add. = 21h]
This register contains the offset value for the internal thermal
voltage output. A twos complement number can be written to
this register, which is then added to the measured result before
it is converted by DAC A. Varying the value in this register has
the effect of varying the temperature span. For example, the
output voltage can represent a temperature span of –128°C to
+127°C or even 0°C to +127°C. In essence, this register changes
the position of 0 V on the temperature scale. Temperatures
other than –128°C to +127°C will produce an upper deadband
on the DAC A output. Because it is an 8-bit register, the
temperature resolution is 1°C. The default value is –40°C.
Table 53. Internal Analog Temperature Offset
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
1* 1* 0* 1* 1* 0* 0* 0*
*Default settings at power-up.
External Analog Temperature Offset Register
(Read/Write) [Add. = 22h]
This register contains the offset value for the external thermal
voltage output. A twos complement number can be written to
this register which is then added to the measured result before it
is converted by DAC B. Varying the value in this register has the
effect of varying the temperature span. For example, the output
voltage can represent a temperature span of –128°C to +127°C
or even 0°C to +127°C. In essence, this register changes the
position of 0 V on the temperature scale. Temperatures other
than –128°C to +127°C will produce an upper deadband on the
DAC B output. Because it is an 8-bit register, the temperature
resolution is 1°C. The default value is –40°C.
ADT7516/ADT7517/ADT7519
Table 54. External Analog Temperature Offset
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
1* 1* 0* 1* 1* 0* 0* 0*
*Default settings at power-up.
VDD VHIGH Limit Register (Read/Write) [Add. = 23h]
This limit register is an 8-bit read/write register that stores the
VDD upper limit, which will cause an interrupt and activate the
INT/INT output (if enabled). For this to happen, the measured
VDD value has to be greater than the value in this register. The
default value is 5.46 V.
Table 55. VDD VHIGH Limit
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
1* 1* 0* 0* 0* 1* 1* 1*
*Default settings at power-up.
VDD VLOW Limit Register (Read/Write) [Add. = 24h]
This limit register is an 8-bit read/write register that stores the
VDD lower limit, which will cause an interrupt and activate the
INT/INT output (if enabled). For this to happen, the measured
VDD value has to be less than or equal to the value in this
register. The default value is 2.7 V.
Table 56. VDD VLOW Limit
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
0* 1* 1* 0* 0* 0* 1* 0*
*Default settings at power-up.
Internal THIGH Limit Register (Read/Write) [Add. = 25h]
This limit register is an 8-bit read/write register that stores the
twos complement of the internal temperature upper limit,
which will cause an interrupt and activate the INT/INT output
(if enabled). For this to happen, the measured internal temp-
erature value has to be greater than the value in this register.
Because it is an 8-bit register, the temperature resolution is 1°C.
The default value is +100°C.
Table 57. Internal THIGH Limit
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
0* 1* 1* 0* 0* 1* 0* 0*
*Default settings at power-up.
Rev. A | Page 35 of 44