SE98 Datasheet, PDF (26/39 Pages) NXP Semiconductors – DDR memory module temp sensor, 3.3 V

NXP Semiconductors
SE98
DDR memory module temp sensor, 3.3 V
9.2 Layout consideration
The SE98 does not require any additional components other than the host controller to
measure temperature. A 0.1 µF bypass capacitor between the V_DD and V_SS pins is
located as close as possible to the power and ground pins for noise protection.
9.3 Thermal considerations
In general, self-heating is the result of power consumption and not a concern, especially
with the SE98, 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 is the formula to calculate the effect of self-heating:
T∆ = R_{th( j-a)} × [(V_DD × I_DD) + (V_OL1 × I_OL1) + (V_OL2 × I_OL2)]
(1)
where:
T∆ = T_j − T_amb
T_j = junction temperature
T_amb = ambient temperature
R_th(j-a) = package thermal resistance
V_OL1 = SDA output low voltage
V_OL2 = EVENT output low voltage
I_OL1 = SDA output current LOW
I_OL2 = EVENT output current LOW.
10. Limiting values
Table 24. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter
Conditions
Min
V_DD
supply voltage
−0.3
V_n
voltage on any other pin SDA, SCL, EVENT pins
−0.3
V_A0
voltage on pin A0
overvoltage input; A0 pin ^[1] −0.3
I_sink
sink current
at SDA, SCL, EVENT pins
−1
V_esd
electrostatic discharge HBM
-
voltage
MM
-
CDM
-
T_j(max)
maximum junction
-
temperature
T_stg
storage temperature
−65
Max
Unit
+4.2
V
+4.2
V
+10
V
+50.0 mA
2500 V
250
V
1000 V
150
°C
+165 °C
[1] In general, application of 10 V on the A0 pin would not damage the pin, but NXP Semiconductors does not
guarantee the overvoltage for this pin.
SE98_4
Product data sheet
Rev. 04 — 2 February 2009
© NXP B.V. 2009. All rights reserved.
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