emc1428 Standard Microsystems Corp., emc1428 Datasheet - Page 17

• Manufacturer Part Number: emc1428
• Description: 1 Degree C Multiple Temperature Sensor With Hw Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

1°C Multiple Temperature Sensor with HW Thermal Shutdown & Hottest of Thermal Zones
Datasheet
APPLICATION NOTE: Current only flows when the TRIP_SET pin is being monitored. At all other times, the internal
APPLICATION NOTE: The TRIP_SET pin circuitry is designed to use a 1% resistor externally. Using a 1% resistor
APPLICATION NOTE: Note that an open condition on the TRIP_SET pin will be decoded as a minimum
SMSC EMC1428
4.3
TRIP_SET Pin
S h u td o w n S e n s o r
The EMC1428’s TRIP_SET pin is an input to the Critical / Thermal Shutdown logic block which sets
the Critical / Thermal shutdown temperature. The system designer creates a voltage level at this input
through a simple resistor connected to GND as shown in
to create an input voltage on the TRIP_SET pin which is translated into a temperature ranging from
65°C to 127°C as enumerated in
H /W T h e rm a l
S /W S e t S e n s o r
S /W S e t S e n s o r
.
.
.
T R IP _ S E T
reference voltage is removed and the TRIP_SET pin will be pulled down to ground.
will result in the Thermal / Critical Shutdown temperature being decoded correctly. If a 5%
resistor is used, then the Thermal / Critical Shutdown temperature may be decoded with as
much as ±1°C error.
temperature threshold level.
Figure 4.2 Block Diagram of Hardware Thermal Shutdown
In te rn a l D io d e
T H E R M L im it
T e m p e ra tu re
T e m p e ra tu re
C o n v e rs io n
C o n v e rs io n
a n d u p to 8
R e g is te rs
C o n v e rs io n
V o lta g e
H a rd w a re T h e rm a l S h u td o w n
Table
DATASHEET
4.1.
S W _ S H D N
S h u td o w n E n a b le
17
S o ftw a re
H W _ S H D N
Figure
4.3. The value of this resistor is used
3 .3 V
S M B u s
T ra ffic
Revision 0.68 (07-08-08)
S Y S _ S H D N