se97pw/1 NXP Semiconductors, se97pw/1 Datasheet - Page 6

• Manufacturer Part Number: se97pw/1
• Description: Se97 Memory Module Temp Sensor With Integrated Spd
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SE97_2
Product data sheet
Fig 5. EVENT output for ‘Interrupt’, ‘Comparator’, and ‘Critical Temp only’ modes
EVENT in ‘Critical Temp only’ mode
(1) EVENT pin shown here is active LOW. It can be programmed to be active HIGH.
EVENT in Comparator mode
EVENT in Interrupt mode
Upper Boundary Alarm
Lower Boundary Alarm
software interrupt clear
7.3.1 Alarm window
alarm window
temperature ( C)
would not affect the SE97. From the system perspective, there will be a practical limit.
That limit will be the voltage necessary for the device monitoring in the interrupt pin to
detect a HIGH on its input. A possible practical limit for a CMOS input would be 0.4 V.
Another thing to consider is the value of the pull-up resistor. When a low supply voltage is
applied to the drain (through the pull-up resistor) it is important to use a higher value
pull-up resistor, to allow a larger maximum signal swing on the EVENT pin. An example
would be if a 150
between 0.9 V and 0.45 V, which may not be enough voltage swing to detect on the
receiver end. As long as a reasonable pull-up resistor is used (> 1 k ) and the receiver
has a low input switching threshold (less than the pull-up voltage), there should no
problem.
In comparator mode, the EVENT pin remains asserted until the temperature falls below
the value programmed in the Upper Boundary Alarm Trip Register or rises above the
value programmed in the Lower Boundary Alarm Trip register, or until the range of these
alarm registers are reprogrammed and the temperature falls inside the alarm limits.
Figure 5
hysteresis as programmed in the Configuration Register.
The alarm window consists of two registers: an Upper Boundary Alarm Trip register (02h),
and a Lower Boundary Alarm Trip register (03h). The Upper Boundary Alarm Trip register
holds the upper temperature trip point, while the Lower Boundary Alarm Trip register holds
the lower temperature trip point. When the EVENT control is enabled, the EVENT output
will be triggered whenever entering or exiting the alarm window.
critical
(1)
(1)
(1)
depicts the EVENT output for all the three modes. All event thresholds use
software clears event
resistor were used as the pull-up to 0.9 V, the output would only toggle
Rev. 02 — 12 October 2007
Memory module temp sensor with integrated SPD
hysteresis
© NXP B.V. 2007. All rights reserved.
002aab233
SE97
time
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