emc1413 Standard Microsystems Corp., emc1413 Datasheet - Page 19

• Manufacturer Part Number: emc1413
• Description: 1?c Temperature Sensor With Beta Compensation And Selectable Address
• Manufacturer: Standard Microsystems Corp.

1°C Temperature Sensor with Beta Compensation and Selectable Address
Datasheet
SMSC EMC1413 / EMC1414
5.2
5.2.1
5.3
CONVERSION RATE
VDD
DN1
DP1
DN2
DP2
32 / sec
64 / sec
The THERM output is asserted independently of the ALERT output and cannot be masked. Whenever
any of the measured temperatures exceed the user programmed THERM Limit values for the
programmed number of consecutive measurements, the THERM output is asserted. Once it has been
asserted, it will remain asserted until all measured temperatures drop below the THERM Limit minus
the THERM Hysteresis (also programmable).
When the THERM pin is asserted, the Therm status bits will likewise be set. Reading these bits will
not clear them until the THERM pin is deasserted. Once the THERM pin is deasserted, the THERM
status bits will be automatically cleared.
THERM Pin Considerations
Because of the decode method used to determine the SMBus Address it is important that the pull-up
resistance on THERM pin be within ±10% tolerance. Additionally, the pull-up resistor on the THERM
pin must be connected to the same 3.3V supply that drives the VDD pin.
For 15ms after power up, the THERM pin must not be pulled low or the SMBus Address will not be
decoded properly. If the system requirements do not permit these conditions, then the THERM pin must
be isolated from their respective busses during this time.
One method of isolating this pin is shown in
The ALERT pin is an open drain output and requires a pull-up resistor to V
operation: interrupt mode and comparator Mode. The mode of the ALERT output is selected via the
ALERT / COMP bit in the Configuration Register (see
THERM Output
ALERT Output
1
2
3
4
5
Table 5.2 Supply Current vs. Conversion Rate for EMC1414 (continued)
EMC1413 /
14
AVERAGE SUPPLY CURRENT
(DEFAULT)
10
ENABLED
9
8
7
6
1050uA
1100uA
THERM / ADDR
GND
SMCLK
SMDATA
ALERT
Figure 5.3 Isolating THERM Pin
DATASHEET
DISABLED
1050uA
1100uA
19
+3.3V
Figure
4.7K -
33K
5.3.
Section
AVERAGING FACTOR (BASED ON 11-BIT
(DEFAULT)
ENABLED
6.4).
0.125x
0.25x
OPERATION)
+2.5 - 5V
DD
Shared THERM
22K
and has two modes of
Revision 1.37 (12-23-09)
DISABLED
0.125x
0.25x