MCP98242 Datasheet, PDF (1/46 Pages) Microchip Technology – Memory Module Temperature Sensor w/ EEPROM for SPD

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: I²C™/SMBus™-Compatible
• Available Packages: TSSOP-8, DFN-8
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
3.3V_DD__{SPD SDA SCL Event}
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 micropro-
cessor-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 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,
I²C/SMBus compatible serial interface, allowing up to
eight devices to be controlled in a single serial bus. To
maintain interchangeability with the I²C/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.
Package Types
MCP98242
8-Pin DFN (2x3)
8-Pin TSSOP
V_{DD 8}
Event ₇
SCLK ₆
SDA 5
1 _A0
2 _A1
3 A2
4 GND
A0 ¹
A1 ²
A2 3
GND 4
8 ^VDD
7 ^Event
6 ^SCLK
5 SDA
© 2006 Microchip Technology Inc.
DS21996A-page 1