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 (maximum)
2-wire Interface: I
2
C™/SMBus Compatible
Available Packages: DFN-8, TDFN-8, UDFN-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 (typical/maximum) 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
microprocessor-based systems. The Event output can
also be configured 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
Software 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
maintain 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 (typical) time out is implemented.
Temperature Sensor Features:
• Temperature-to-Digital Converter
• Operating Current: 200 µA (typical)
• 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 (typical) for 3.5 ms (typical)
- Read
100
µA (typical)
• 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/UDFN (2x3) * 8-Pin TSSOP
A0 1
A1 2
A2 3
EP
9
8 V
DD
A0 1
8 V
DD
7 Event
6 SCLK
5 SDA
7 Event A1 2
6 SCLK A2 3
5 SDA GND 4
3.3V
DD
_
SPD
SDA
SCL
Event
GND 4
* Includes Exposed Thermal Pad (EP); see
Table 3-1.
2010 Microchip Technology Inc.
DS21996D-page 1
MCP98242
Notes:
DS21996D-page 2
2010 Microchip Technology Inc.
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
I
DD
I
DD
I
DD
I
SHDN
V
POR
V
POR
°C/V
DD
°C/V
DD
T
ACY
T
ACY
T
ACY
T
ACY
t
CONV
—
—
—
—
—
—
200
1100
100
1
2.3
1.6
500
2000
500
3
—
—
µA
µA
µA
µA
V
V
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
“Summary of Temperature Sensor
Power-on Default”)
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
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
½-40°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
Note 1:
—
—
-1.0
-2.0
-3.0
—
—
±0.4
±0.15
±0.5
±1
±2
-2
65
—
—
+1.0
+2.0
+3.0
—
125
°C/V
°C
°C
°C
°C
°C
ms
15 s/sec (typical) (See
Section 5.2.3.3
“Temperature Resolution”)
V
OH
= V
DD
I
OL
= 3 mA
—
Applied at A0 pin,
Note 1
I
OH
V
OL
t
WC
—
V
HI_WP
—
—
—
1M
8
—
—
3
—
—
1
0.4
5
—
12
µA
V
ms
V
cycles V
DD
= 5V,
Note 1
Characterized but not production tested.
2010 Microchip Technology Inc.
DS21996D-page 3
MCP98242
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
DFN
TSSOP
Note 1:
Sym
t
RES
t
RES
Min
—
—
Typ
0.7
1.4
Max
—
—
Unit
s
s
Conditions
Time to 63% (89°C)
25°C (Air) to 125°C (oil bath)
Characterized but not production tested.
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
Voltage
V
DD
INPUT
V
IH
V
IL
V
OL
Voltage
V
DD
OUTPUT
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
Note 1:
Operation in this range must not cause T
J
to exceed Maximum Junction Temperature (+150°C).
T
A
T
A
T
A
-20
-40
-65
—
—
—
+125
+125
+150
°C
°C
°C
(Note
1)
Sym
Min
Typ
Max
Units
Conditions
DS21996D-page 4
2010 Microchip Technology Inc.
MCP98242
TEMPERATURE CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 3.0V to 3.6V, GND = Ground.
Parameters
Thermal Resistance, 8L-DFN
Thermal Resistance, 8L-TDFN
Thermal Resistance, 8L-TSSOP
Note 1:
0
Sym
JA
JA
JA
Min
—
—
—
Typ
84.5
41
139
Max
—
—
—
Units
°C/W
°C/W
°C/W
Conditions
Operation in this range must not cause T
J
to exceed Maximum Junction Temperature (+150°C).
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
Sym
Min
Typ
Max
Units
Conditions
I
2
C™/SMBus
2-Wire I
2
C™/SMBus-Compatible Interface
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
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
10
4.7
4.0
—
—
250
300
4.7
4.0
4.0
4.7
25
—
—
—
—
—
—
—
—
—
—
—
40
100
—
—
1000
300
—
—
—
—
—
—
50
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)
TIMING DIAGRAM
TA
R
T
-S
TA
RT
P
IG
H
TO
O
U
-S
W
EE
-F
R
t
S
U
-S
t
H
t
H
SD
A
SC
LK
t
O
U
T
AT
A
U
-D
t
S
Start Condition
Data Transmission
t
H
-D
AT
A
t
R
,t
F
t
L
Stop Condition
2010 Microchip Technology Inc.
t
S
DS21996D-page 5
t
B
