LM81BIMT-3/NOPB National Semiconductor, LM81BIMT-3/NOPB Datasheet - Page 20

• Manufacturer Part Number: LM81BIMT-3/NOPB
• Description: IC MONITOR SYS HARDWARE 24TSSOP
• Manufacturer: National Semiconductor

Specifications of LM81BIMT-3/NOPB

• Function: Hardware Monitor
• Topology: ADC (Sigma Delta), Comparator, Fan Speed Control, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 2.8 V ~ 3.8 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP
• Monitored Voltage: 2.5 V , 3.3 V , 5 V , 12 V
• Manual Reset: Not Resettable
• Watchdog: Watchdog
• Battery Backup Switching: No
• Supply Voltage (max): 3.8 V
• Supply Voltage (min): 2.8 V
• Supply Current (typ): 400 uA (Typ)
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM81BIMT-3; *LM81BIMT-3/NOPB; LM81BIMT-3

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Functional Description
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
indefinitely until reset by reading Interrupt Status Register 1.
Once reset if the temperature remains above the T
setpoint the interrupt will again be activated at the comple-
tion of another conversion cycle. If temperature is less than
or equal to T
*
Note: Interrupt resets occur only when interrupt Status Register 1 is read.
FIGURE 11. Normal Repetitive Interrupt Response
HIGH
HIHYST
causes an interrupt that will remain active
the interrupt will not be activated.
Diagram
(Continued)
DS100072-16
HIHYST
20
Normal One-Time Interrupt Mode is shown in Figure 12
and operates in the following way: T_CRIT_A is disabled.
Exceeding T
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
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
the temperature is less than or equal to T
disabled.
*
Note: Interrupt resets occur only when interrupt Status Register 1 is read.
Note: Interrupt resets occur only when interrupt Status Register 1 is read.
FIGURE 12. One-Time Interrupt Response Diagram
HIGH
FIGURE 13. Normal Comparator Mode
causes an interrupt that will remain activated until
HIGH
causes an interrupt that will remain active
HIHYST
and then exceeds T
HIGH
DS100072-18
DS100072-17
HIGH
. T
LOW
during
is