MCP98242
Memory Module Temperature Sensor w/EEPROM for SPD
Features
•
•
•
•
•
•
Temperature Sensor + 256 Byte Serial EEPROM
EEPROM for Serial Presence Detect (SPD)
Optimized for Voltage Range: 3.0V to 3.6V
Shutdown/Standby Current: 3 µA (max.)
2-wire Interface: I
2
C™/SMBus™-Compatible
Available Packages: DFN-8, TDFN-8, TSSOP-8
Description
Microchip Technology Inc.’s MCP98242 digital
temperature sensor converts temperature from -40°C
and +125°C to a digital word. This sensor meets
JEDEC Specification JC42.4 Mobile Platform Memory
Module Thermal Sensor Component. It provides an
accuracy of ±0.5°C/±1°C (typ./max.) from +75°C to
+95°C. In addition, this device has an internal 256 Byte
EEPROM which can be used to store memory module
and vendor information.
The MCP98242 digital temperature sensor comes with
user-programmable registers that provide flexibility for
DIMM temperature-sensing applications. The registers
allow user-selectable settings such as Shutdown or
Low-Power modes and the specification of
temperature event and critical output boundaries.
When the temperature changes beyond the specified
boundary limits, the MCP98242 outputs an Event
signal. The user has the option of setting the Event
output signal polarity as either an active-low or active-
high comparator output for thermostat operation, or as
a temperature event interrupt output for microproces-
sor-based systems. The Event output can also be con-
figured as a critical temperature output.
The EEPROM is designed specifically for DRAM
DIMMs (Dual In-line Memory Modules) Serial Presence
Detect (SPD). The lower 128 bytes (address 00h to
7Fh) can be Permanent Write Protected (PWP) or Soft-
ware Reversible Write Protected (SWP). This allows
DRAM vendor and product information to be stored and
write protected. The upper 128 bytes (address 80h to
FFh) can be used for general purpose data storage.
These addresses are not write protected.
This sensor has an industry standard 2-wire, I
2
C/
SMBus compatible serial interface, allowing up to eight
devices to be controlled in a single serial bus. To main-
tain interchangeability with the I
2
C/SMBus interface the
electrical specifications are specified with the operating
voltage of 3.0V to 3.6V. In addition, a 40 ms (typ.) time
out is implemented.
Temperature Sensor Features
• Temperature-to-Digital Converter
• Operating Current: 200 µA (typ.)
• Accuracy:
-
±0.5°C/±1°C (typ./max.)
→
+75°C to +95°C
- ±1°C/±2°C (typ./max.)
→
+40°C to +125°C
- ±2°C/±3°C (typ./max.)
→
-20°C to +125°C
Serial EEPROM Features
• Operating Current:
- Write
→
1.1 mA (typ.) for 3.5 ms (typ.)
- Read
→
100 µA (typ.)
• Permanent and Reversible Software Write Protect
• Software Write Protection for the lower 128 bytes
• Organized as 1 block of 256 bytes (256x8)
Typical Applications
• DIMM Modules
• Laptops, Personal Computers and Servers
• Hard Disk Drives and Other PC Peripherals
DIMM MODULE
Memory
MCP98242
Temperature Sensor + EEPROM
• ±0.5°C (typ.) Sensor
• 256 Byte EEPROM for SPD
Package Types
MCP98242
8-Pin DFN/TDFN (2x3)
V
DD
8
Event 7
SCLK 6
1 A0
2 A1
3 A2
4 GND
8-Pin TSSOP
A0 1
A1 2
A2 3
GND 4
8 V
DD
7 Event
6 SCLK
5 SDA
3.3V
DD
_
SPD
SDA
SCL
Event
SDA 5
©
2008 Microchip Technology Inc.
DS21996B-page 1
MCP98242
1.0
ELECTRICAL
CHARACTERISTICS
†Notice:
Stresses above those listed under “Maximum
ratings” may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational listings of this specification is not implied.
Exposure to maximum rating conditions for extended periods
may affect device reliability.
Absolute Maximum Ratings †
V
DD
.................................................................................. 6.0V
Voltage at all Input/Output pins ............... GND – 0.3V to 6.0V
Pin A0.................................................... GND – 0.3V to 12.5V
Storage temperature .....................................-65°C to +150°C
Ambient temp. with power applied ................-40°C to +125°C
Junction Temperature (T
J
)........................................... +150°C
ESD protection on all pins (HBM:MM) ................. (4 kV:300V)
Latch-Up Current at each pin (25°C)........................ ±200 mA
DC CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 3.0V to 3.6V, GND = Ground, SDA/SCL pulled-up to
V
DD
, and T
A
= -20°C to +125°C.
Parameters
Power Supply
Operating Voltage
Operating Current
Temperature Sensor
EEPROM write
EEPROM read
Shutdown Current
Power On Reset (POR)
Threshold
Power Supply Rejection,
T
A
= +25°C
Temperature Sensor Accuracy
+75°C < T
A
≤
+95°C
+40°C < T
A
≤
+125°C
-20°C < T
A
≤
+125°C
T
A
=
-40°C
Conversion Time
0.25°C/bit
Event Output (Open-drain)
High-level Current (leakage)
Low-level Voltage
EEPROM
Write Cycle (byte/page)
Endurance T
A
= +25°C
Write Protect High Voltage
Thermal Response
DFN
TSSOP
Note 1:
t
RES
t
RES
—
—
0.7
1.4
—
—
s
s
Time to 63% (89°C)
25°C (Air) to 125°C (oil bath)
t
WC
—
V
HI_WP
—
1M
8
3
—
—
5
—
12
ms
V
—
Applied at A0 pin,
Note 1
cycles V
DD
= 5V,
Note 1
I
OH
V
OL
—
—
—
—
1
0.4
µA
V
V
OH
= V
DD
I
OL
= 3 mA
t
CONV
—
65
125
ms
15 s/sec (typ.) (See Section 5.2.3.2)
T
ACY
T
ACY
T
ACY
T
ACY
-1.0
-2.0
-3.0
—
±0.5
±1
±2
-2
+1.0
+2.0
+3.0
—
°C
°C
°C
°C
I
DD
I
DD
I
DD
I
SHDN
V
POR
V
POR
Δ°C/ΔV
DD
Δ°C/ΔV
DD
—
—
—
—
—
—
—
—
200
1100
100
1
2.3
1.6
±0.4
±0.15
500
2000
500
3
—
—
—
—
µA
µA
µA
µA
V
V
°C/V
°C
EEPROM Inactive
Sensor in Shutdown Mode (for t
WC
)
Sensor in Shutdown Mode
EEPROM Inactive,
Sensor in Shutdown Mode
Temperature Sensor (V
DD
falling)
EEPROM (V
DD
falling) (see
Section 5.4)
V
DD
= 3.0V to 3.6V
V
DD
= 3.3V+150 mV
PP AC
(0 to 1 MHz)
V
DD
3.0
—
3.6
V
Sym
Min
Typ
Max
Unit
Conditions
Characterized but not production tested.
DS21996B-page 2
©
2008 Microchip Technology Inc.
MCP98242
INPUT/OUTPUT PIN DC CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 3.0V to 3.6V, GND = Ground and
T
A
= -20°C to +125°C.
Parameters
Input
High-level Voltage
Low-level Voltage
Input Current
Output (SDA)
Low-level Voltage
High-level Current (leakage)
Low-level Current
Capacitance
SDA and SCL Inputs
Hysteresis
V
HYST
—
0.5
—
V
Note:
The serial inputs do not load the serial bus for V
DD
range of 1.8V to 5.5V.
V
OL
I
OH
I
OL
C
IN
—
—
6
—
—
—
—
5
0.4
1
—
—
V
µA
mA
pF
I
OL
= 3 mA
V
OH
= V
DD
V
OL
= 0.6V
V
IH
V
IL
I
IN
2.1
—
—
—
—
—
—
0.8
±5
V
V
µA
Sym
Min
Typ
Max
Units
Conditions
Serial Input/Output (SCL, SDA, A0, A1, A2)
GRAPHICAL SYMBOL DESCRIPTION
OUTPUT
INPUT
Voltage
V
DD
V
IH
V
IL
Voltage
V
DD
V
OL
I
OL
Current
I
IN
time
Current
I
OH
time
TEMPERATURE CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 3.0V to 3.6V, GND = Ground.
Parameters
Temperature Ranges
Specified Temperature Range
Operating Temperature Range
Storage Temperature Range
Thermal Package Resistances
Thermal Resistance, 8L-DFN
Thermal Resistance, 8L-TDFN
Thermal Resistance, 8L-TSSOP
Note 1:
θ
JA
θ
JA
θ
JA
—
—
—
41
41
123.7
—
—
—
°C/W
°C/W
°C/W
T
A
T
A
T
A
-20
-40
-65
—
—
—
+125
+125
+150
°C
°C
°C
(Note 1)
Sym
Min
Typ
Max
Units
Conditions
Operation in this range must not cause T
J
to exceed Maximum Junction Temperature (+150°C).
©
2008 Microchip Technology Inc.
DS21996B-page 3
MCP98242
SENSOR AND EEPROM SERIAL INTERFACE TIMING SPECIFICATIONS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 3.0V to 3.6V, GND = Ground, T
A
= -20°C to +125°C,
C
L
= 80 pF, and all limits measured to 50% point.
Parameters
Serial Port Frequency
Low Clock
High Clock
Rise Time
Fall Time
Data Setup Before SCLK High
Data Hold After SCLK Low
Start Condition Setup Time
Start Condition Hold Time
Stop Condition Setup Time
Bus Idle
Time Out
Sym
f
SC
t
LOW
t
HIGH
t
R
t
F
t
SU-DATA
t
H-DATA
t
SU-START
t
H-START
t
SU-STOP
t
B_FREE
t
OUT
Min
10
4.7
4.0
—
—
250
300
4.7
4.0
4.0
4.7
25
Typ
—
—
—
—
—
—
—
—
—
—
—
40
Max
100
—
—
1000
300
—
—
—
—
—
—
50
Units
kHz
µs
µs
ns
ns
ns
ns
µs
µs
µs
µs
ms
Temp. Sensor Only (characterized
but not production tested)
(V
IL MAX
- 0.15V) to (V
IH MIN
+
0.15V)
(V
IH MIN
+ 0.15V) to (V
IL MAX
-
0.15V)
I
2
C/SMBus
Conditions
2-Wire I
2
C/SMBus-Compatible Interface
0
TIMING DIAGRAM
-S
TA
R
T
-S
TA
R
T
P
IG
H
TO
O
W
-S
U
U
t
S
t
H
t
H
SD
A
SC
LK
t
O
U
T
AT
A
-D
U
t
S
Start Condition
Data Transmission
t
H
-D
AT
A
t
R
,t
F
t
L
Stop Condition
DS21996B-page 4
©
2008 Microchip Technology Inc.
t
S
t
B
-F
R
EE
MCP98242
2.0
Note:
TYPICAL PERFORMANCE CURVES
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note:
Unless otherwise indicated, V
DD
= 3.0V to 3.6V, GND = Ground, SDA/SCL pulled-up to V
DD
, and
T
A
= -20°C to +125°C.
3.0
Temperature Accuracy (°C)
V
DD
= 3.0V to 3.6V
10000
V
DD
= 3.3V to 3.6V
2.0
1000
1.0
0.0
-1.0
I
DD
(µA)
Spec. Limits
EEPROM Write (Sensor in Shutdown Mode)
100
Sensor (EEPROM Inactive)
10
-2.0
-3.0
-40
-20
0
20
40
60
T
A
(°C)
80
100
120
EEPROM Read (Sensor in Shutdown Mode)
1
-40
-20
0
20
40
60
T
A
(°C)
80
100
120
FIGURE 2-1:
Accuracy.
Average Temperature
FIGURE 2-4:
Temperature.
3.00
Supply Current vs.
70%
60%
Occurrences
50%
40%
30%
20%
10%
0%
-1.00
-0.75
-0.50
-0.25
0.00
0.25
0.50
0.75
1.00
T
A
= +95°C
V
DD
= 3.3V
221 units
V
DD
= 3.0V to 3.6V
2.50
I
SHDN
(µA)
2.00
1.50
1.00
0.50
0.00
-40
-20
0
20
40
60
T
A
(°C )
80
100
120
Temperature Accuracy (°C)
FIGURE 2-2:
Temperature Accuracy
Histogram, T
A
= +95°C.
70%
60%
Occurrences
50%
40%
30%
20%
10%
0%
-1.00
-0.75
-0.50
-0.25
0.00
0.25
0.50
0.75
1.00
T
A
= +75°C
V
DD
= 3.3V
221 units
FIGURE 2-5:
Temperature.
Shutdown Current vs.
3
2.5
V
POR
(V)
2
1.5
1
0.5
0
-40
-20
0
20
40
60
T
A
(°C)
80
100
120
Temperature Accuracy (°C)
FIGURE 2-3:
Temperature Accuracy
Histogram, T
A
= +75°C.
FIGURE 2-6:
Power-on Reset Threshold
Voltage vs. Temperature.
©
2008 Microchip Technology Inc.
DS21996B-page 5
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