SE98ATP,547 NXP Semiconductors, SE98ATP,547 Datasheet - Page 28

• Manufacturer Part Number: SE98ATP,547
• Description: IC TEMP SENSOR DDR 8-HWSON
• Manufacturer: NXP Semiconductors

Specifications of SE98ATP,547

• Function: Temp Monitoring System (Sensor)
• Topology: ADC (Sigma Delta), Register Bank
• Sensor Type: Internal
• Sensing Temperature: -40°C ~ 125°C
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 1.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-WSON (Exposed Pad), 8-HWSON
• Temperature Threshold: Programmable
• Full Temp Accuracy: +/- 1 C
• Digital Output - Bus Interface: 2-Wire, SMBus, I2C
• Digital Output - Number Of Bits: 11
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 1.7 V
• Description/function: DDR Memory Module Temperature Sensor
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 250 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 568-4731-2; SE98ATP,147

NXP Semiconductors
SE98A_4
Product data sheet
9.1 SE98A in memory module application
9.2 Layout consideration
9.3 Thermal considerations
Figure 15
SPD. The SE98A is centered in the memory module to provide the function to monitor the
temperature of the DRAM. In the event of overheat, the SE98A triggers the EVENT output
and the memory controller can throttle the memory bus to slow the DRAM, or the CPU can
increase the refresh rate for the DRAM. The memory controller can also read the SE98A
and watch the DRAM thermal behavior.
The SE98A does not require any additional components other than the host controller to
measure temperature. A 0.1 μF bypass capacitor between the V
located as close as possible to the power and ground pins for noise protection.
In general, self-heating is the result of power consumption and not a concern, especially
with the SE98A, which consumes very low power. In the event the SDA and EVENT pins
are heavily loaded with small pull-up resistor values, self-heating affects temperature
accuracy by approximately 0.5 °C.
Equation 1
where:
ΔT
[
Fig 15. System application
(
ΔT = T
T
T
R
V
I
V
V
DD(AV)
V
j
amb
DD
OL(SDA)
OL(EVENT)
th(j-a)
DD
= junction temperature
=
= supply voltage
R
= ambient temperature
×
th j-a
j
= package thermal resistance
= average supply current
I
− T
DD AV
shows the SE98A being placed in the memory module application with the
(
= LOW-level output voltage on pin SDA
is the formula to calculate the effect of self-heating:
(
amb
= LOW-level output voltage on pin EVENT
)
DIMM
×
)
DRAM
)
+
(
V
Rev. 04 — 25 November 2009
OL SDA
MEMORY CONTROLLER
(
)
DRAM
×
SMBus
I
OL
SDA
(
sin
DDR memory module temp sensor, 1.7 V to 3.6 V
k
) SDA
(
SCL
SE98A
)
SPD
)
+
(
V
OL EVENT
EVENT
(
DRAM
)
×
I
OL
DD
(
sin
and V
k
DRAM
)EVENT
CPU
002aad760
© NXP B.V. 2009. All rights reserved.
SS
SE98A
)
pins is
]
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