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ADT7516/ADT7517/ADT7519

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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

*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

*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.

Table 54. External Analog Temperature Offset

*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

*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

Table 56. VDD VLOW Limit

*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

*Default settings at power-up.

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