LM85 National Semiconductor, LM85 Datasheet - Page 2

• Manufacturer Part Number: LM85
• Description: Hardware Monitor with Integrated Fan Control
• Manufacturer: National Semiconductor

www.national.com
Connection Diagram
Information on the differences between the LM85BIMQ and LM85CIMQ can be found in Section 6.0. It is highly recommended
that all new designs use the LM85BIMQ.
Pin Descriptions
SMBDAT
SMBCLK
Symbol
V
VID0
VID1
VID2
VID3
VID4
GND
3.3V
2.5V
12V
5V
CCP
LM85BIMQX or LM85CIMQX (2500 units per tape and reel)
Pin
19
20
21
22
23
1
2
5
6
7
8
4
3
LM85BIMQ or LM85CIMQ (55 units per rail), or
(Open-Drain)
Analog Input
Analog Input
Analog Input
Analog Input
Digital Input
Digital Input
Digital Input
Digital Input
Digital Input
Digital Input
Digital I/O
GROUND
POWER
Typ
NS Package MQA24
24 Pin QSOP
Top View
Name and Function/Connection
System Management Bus Data. Open-drain output. 5V tolerant,
SMBus 2.0 compliant.
System Management Bus Clock. Tied to Open-drain output. 5V
tolerant, SMBus 2.0 compliant.
Voltage identification signal from the processor. This value is read
in the VID0–VID4 Status Register.
Voltage identification signal from the processor. This value is read
in the VID0–VID4 Status Register.
Voltage identification signal from the processor. This value is read
in the VID0–VID4 Status Register.
Voltage identification signal from the processor. This value is read
in the VID0–VID4 Status Register.
Voltage identification signal from the processor. This value is read
in the VID0–VID4 Status Register.
+3.3V pin. Can be powered by +3.3V Standby power if monitoring
in low power states is required. This pin also serves as the analog
input to monitor the 3.3V supply. This pin should be bypassed
with a 0.1µf capacitor in parallel with 100pf. A bulk capacitance of
approximately 10µf needs to be in the near vicinity of the LM85.
Ground for all analog and digital circuitry.
Analog input for +5V monitoring.
Analog input for +12V monitoring.
Analog input for +2.5V monitoring.
Analog input for +V
2
CCP
(processor voltage) monitoring.
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