LM81CIMT-3/NOPB National Semiconductor, LM81CIMT-3/NOPB Datasheet - Page 31

• Manufacturer Part Number: LM81CIMT-3/NOPB
• Description: IC MONITOR SYS HARDWAR 24-TSSOP
• Manufacturer: National Semiconductor

Specifications of LM81CIMT-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
• Supply Voltage Range: 2.8V To 3.8V
• Reset Type: Active-Low
• Supply Current: 1.4mA
• Digital Ic Case Style: TSSOP
• No. Of Pins: 24
• Operating Temperature Range: -40°C To +125°C
• Rohs Compliant: Yes
• 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: *LM81CIMT-3; *LM81CIMT-3/NOPB; LM81CIMT-3

Functional Description
13.16 Value RAM — Address 15h–3Fh
Note: Setting all ones to the high limits for voltages and fans (0111 1111 binary for temperature) means interrupts will never be generated except the case when
Address A6–A0
voltages go below the low limits.
For voltage input high limits, the device is doing a greater than comparison. For low limits, however, it is doing a less than or equal to comparison.
2Ah
2Bh
2Ch
2Dh
2Eh
3Ah
3Bh
3Ch
3Dh
3Eh
15h
19h
20h
21h
22h
23h
24h
25h
26h
27h
28h
29h
2Fh
30h
31h
32h
33h
34h
35h
36h
37h
38h
39h
3Fh
Manufacturers Test Register
DAC data register; power on default
+2.5Vin reading
Vccp1 reading
+3.3Vin reading
+5Vin reading
+12Vin reading
Vccp2 reading
Reserved reading
Temperature reading (8 MSBs)
FAN1 reading
Note: This location stores the number of counts of the internal clock per revolution.
FAN2 reading
Note: This location stores the number of counts of the internal clock per revolution.
Reserved
+2.5Vin High Limit
+2.5Vin Low Limit
Vccp1 High Limit
Vccp1 Low Limit
+3.3Vin High Limit
+3.3Vin Low Limit
+5Vin High Limit
+5Vin Low Limit
+12Vin High Limit
+12Vin Low Limit
Vccp2 High Limit
Vccp2 Low Limit
T_CRIT Limit (Extended Mode)
LOW Limit (Extended Mode)
HIGH Temperature Limit
HIHYST Temperature Limit
FAN1 Fan Count Limit
Note: It is the number of counts of the internal clock for the Low Limit of the fan speed.
FAN2 Fan Count Limit
Note: It is the number of counts of the internal clock for the Low Limit of the fan speed.
Reserved
Company Identification. The number in this register identifies National Semiconductor (0000 0001)
Stepping Register LM81 revision number (0000 0011)
(Continued)
<
31
7:0
>
=1111 1111 binary
Description
www.national.com