LM81BIMT-3/NOPB National Semiconductor, LM81BIMT-3/NOPB Datasheet - Page 29

• 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

0-3
4-5
6-7
2-6
1-7
0-1
2-6
Bit
Bit
Bit
Bit
0-1
7
0
7
Functional Description
13.10 VID/Fan Divisor Register — Address 47h
Power on default –
13.11 Serial Bus Address Register — Address 48h
Power on default – Serial Bus address
13.12 VID4 Register — Address 49h
Power on default –
13.13 Temperature Configuration Register — Address 4Bh
Power on default –
Serial Bus
Address
Serial Bus
Address
Reserved
VID4
Reserved
Temperature
Interrupt Mode
Select Bits
Reserved
Temperature
Resolution
VID
FAN1 RPM
Control
FAN2 RPM
Control
<
Name
Name
Name
Name
3:0
>
<
<
<
7:4
7:1
7:0
>
>
>
Read Only
Read/Write
Read/Write
Read/Write
is 0101, and
= 100 000,
= 0000 0001 binary
Read Only
Read/Write
Read/Write
Read Only
Read/Write
Read/Write
Read/Write
Read Only
Read/Write
Read/Write
Read/Write
<
(Continued)
<
<
0
6:0
>
3:0
The VID
operating voltage (e.g. 1.5V to 2.9V).
FAN1 Speed Control.
<
<
<
<
FAN2 Speed Control.
<
<
<
<
= VID4.
>
5:4
5:4
5:4
5:4
7:6
7:6
7:6
7:6
Serial Bus address
Serial Bus address
VID4 input from Pentium/PRO power supply that indicate the operating voltage of
the processor (e.g. 1.5V to 2.9V).
The state of these bits select the interrupt mode for INT as described below.
For 8-bit plus sign temperature resolution:
<
<
<
>
1:0
1:0
1:0
is mapped to VID
= 010 11(A1)(A0) and
>
>
>
>
>
>
>
>
>
>
>
= 00 - divide by 1;
= 01 - divide by 2;
= 10 - divide by 4;
= 11 - divide by 8.
= 00 - divide by 1;
= 01 - divide by 2;
= 10 - divide by 4;
= 11 - divide by 8.
<
= 00 or
= 01: One-Time Interrupt Mode
= 10: Comparator Mode
3:0
>
inputs from the Pentium/PRO power supplies that indicate the
<
1:0
29
<
<
<
>
1:0
6:2
3:0
= 11: Repetitive Interrupt Mode
>
>
<
>
7
= 010 11
= A1 A0
>
= 0 binary
Description
Description
Description
Description
<
7
>
= LSB ( 0.5˚C)
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