Rainbow Electronics LM81 - Manual (Page 20)

Functional Description
(Continued)
8.2 Temperature Interrupts
INT and T_CRIT_A outputs are provided for temperature
interrupt. Temperature interrupts have a normal and an ex-
tended option of operation. Each option has three different
modes of operation: Repetitive Interrupt, One-Time Interrupt
and Comparator.
Normal Repetitive Interrupt Mode is shown in Figure 11
and operates in the following way: T_CRIT_A is disabled.
Exceeding T
HIGH
causes an interrupt that will remain active
indefinitely until reset by reading Interrupt Status Register 1.
Once reset if the temperature remains above the T
HIHYST
setpoint the interrupt will again be activated at the comple-
tion of another conversion cycle. If temperature is less than
or equal to T
HIHYST
the interrupt will not be activated.
Normal One-Time Interrupt Mode is shown in Figure 12
and operates in the following way: T_CRIT_A is disabled.
Exceeding T
HIGH
causes an interrupt that will remain active
indefinitely until reset by reading Interrupt Status Register 1.
Another interrupt will not occur until the temperature drops to
less than or equal to T
HIHYST
and then exceeds T
HIGH
during
a subsequent conversion. After power up this mode is se-
lected as default.
Normal Comparator Mode is shown in Figure 13 and op-
erates in the following way: T_CRIT_A is disabled. Exceed-
ing T
HIGH
causes an interrupt that will remain activated until
the temperature is less than or equal to T
HIGH
. T
LOW
is
disabled.
DS100072-16
* Note: Interrupt resets occur only when interrupt Status Register 1 is read.
FIGURE 11. Normal Repetitive Interrupt Response
Diagram
DS100072-17
* Note: Interrupt resets occur only when interrupt Status Register 1 is read.
FIGURE 12. One-Time Interrupt Response Diagram
DS100072-18
* Note: Interrupt resets occur only when interrupt Status Register 1 is read.
FIGURE 13. Normal Comparator Mode
LM81
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