STTS424E02BDA6E STMICROELECTRONICS [STMicroelectronics], STTS424E02BDA6E Datasheet - Page 2

• Manufacturer Part Number: STTS424E02BDA6E
• Description: Memory module temperature sensor with a 2Kb SPD EEPROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Description
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The STTS424E02 is targeted for DIMM Modules in Mobile Personal Computing Platforms
(Laptops), Server Memory Modules and other industrial applications. The Thermal Sensor
(TS) in the STTS424E02 is fully compliant with the JEDEC 42.4 specification, which defines
Memory Module Thermal Sensors requirements for Mobile platforms. The 2Kbit Serial
Presence Detect (SPD) I
(EEPROM) in the STTS424E02 is organized as 256 x8 bits and is functionally identical to
the industry standard M34E02.
Ambient temperature sensing range for the temperature sensor is -40°C to +125°C per
JC42.4 specifications. The operating temperature range for the SPD EEPROM is
guaranteed for -40°C to +85°C.
The TS-SPD EEPROM combination provides space as well as cost savings for Mobile and
Server Platform Dual Inline Memory Modules (DIMM) manufacturers, as it is packaged in
the compact 2mm x 3mm 8-lead DFN package which has a height that will not exceed
0.9mm. It is also available in the JEDEC compliant TSSOP8 package.
The temperature sensor includes a band gap-based temperature sensor and 10-bit Analog-
to-Digital Converter (ADC) which monitor and digitize the temperature to a resolution of up
to 0.25°C. The typical accuracies over these temperature ranges are:
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The temperature sensor in the STTS424E02 is specified for operating at supply voltages
from 2.7V to 3.6V. Operating at 3.3V, the supply current is 100µA (typ).
The on-board sigma delta ADC converts the measured temperature to a digital value that is
calibrated in °C. For Fahrenheit applications, a lookup table or conversion routine is
required. The STTS424E02 is factory-calibrated and requires no external components to
measure temperature.
The digital temperature sensor component has user-programmable registers that provide
the capabilities for DIMM temperature-sensing applications. The open drain Event output pin
is active when the monitoring temperature exceeds a programmable limit, or it falls above or
below an alarm window. The user has the option to set the Event output as a critical
temperature output. This pin can be configured to operate in either a comparator mode for
thermostat operation or in interrupt mode.
The 2Kbit serial EEPROM memory in the STTS424E02 has the ability to permanently lock
the data in its first half (upper) 128 bytes (locations 00h to 7Fh). This facility has been
designed specifically for use in DRAM DIMMs with SPD. All of the information concerning
the DRAM module configuration (e.g. access speed, size, and organization) can be kept
write protected in the first half of the memory. The second half (lower) 128 bytes of the
memory can be write protected using two different software write protection mechanisms.
By sending the device a specific sequence, the first 128 bytes of the memory become write
protected: permanently or resettable. In the STTS424E02 the EEPROM Write Control (WC)
is always held low. Thus, the write protection of the memory array is dependent on whether
the software protection has been set.
±3°C (max) over the full temperature measurement range of –40°C to 125°C,
±2°C in the +40°C to +125°C temperature range, and
±1°C in the +75°C to +95°C temperature range.
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C-compatible Electrically Erasable Programmable Memory