EMC1002-1-ACZT SMSC, EMC1002-1-ACZT Datasheet - Page 9

• Manufacturer Part Number: EMC1002-1-ACZT
• Description: Board Mount Temperature Sensors Dual Zone SMBus Temp Snsr
• Manufacturer: SMSC

Specifications of EMC1002-1-ACZT

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

1°C Dual SMBus Sensor with Resistance Error Correction
Datasheet
Chapter 4 Product Description
SMSC EMC1002
4.1
Temperature Monitors
The EMC1002 is an SMBus sensor that can monitor internal temperature and one remote diode
temperature. The sensor is typically used with an SMBus host such as an SMSC SIO device or an
SMSC fan control chip.
Thermal management is performed in cooperation with the host device. The host reads the
temperature data from the EMC1002 and takes appropriate action such as controlling fan speed or
processor clock frequency. The EMC1002 has programmable temperature limit registers that define
a safe operating window. After the host has configured the temperature limits, the EMC1002 can
perform as a free-running independent watchdog to warn the host of temperature hot spots without
requiring the host to poll the device.
The EMC1002 has
Thermal diode temperature measurements are based on the change in forward bias voltage (ΔV
a diode when operated at two different currents:
The change in
Run Mode: In this mode, the EMC1002 continuously converts temperature data and updates its
registers. The rate of temperature conversion is configured as shown in
Register," on page
Standby Mode: In this mode, the EMC1002 is placed in standby to conserve power as described
in
Δ
4.7, "Standby Mode," on page
DP
DN
V
BE
EMC1002
Internal
Diode
=
V
Δ
BE
V
_
BE
HIGH
t
wo basic modes of operation:
voltage is proportional to absolute temperature T.
15.
−
SMDATA
ALERT/THERM2
ADDR/THERM
SMCLK
V
BE
Figure 4.1 System Overview
_
LOW
DATASHEET
13.
=
η
kT
q
9
ln
⎛
⎜ ⎜
⎝
I
I
HIGH
LOW
Interface
SMBus
⎞
⎟ ⎟
⎠
Host
where:
k = Boltzmann’s constant
T = absolute temperature in Kelvin
q = electron charge
η
= diode ideality factor
4.11, "Conversion Rate
Driver
Fan
Revision 1.4 (12-18-07)
BE
) of