NXP | SE97BTP,547

The SE97B is a high-accuracy digital thermal sensor which is fully compliant with the new 2nd generation JEDEC JC42.4 DRAM DIMM (dual in-line memory modules) specification that supports Intel’s Romley processor. There is an integrated analog-to-digital converter (ADC) which monitors and digitizes the temperature with a resolution of 0.125 °C and an accuracy of +/- 1 °C maximum over +75 to +95 °C (temperature range of interest for DIMMs). For computing applications, it is intended for monitoring the temperature of the DRAM (mandatory on server RDIMM and UDIMM-ECC and optional on notebook SO-DIMM).  Thermal sensing on the DIMM allows the CPU to reduce the speed of the memory traffic as required to prevent memory overheating but allowing maximum performance without the previously artificially lowered limits based on algorithms and design studies.

The SE97B device integrates both a thermal sensor and a 2-kbit Serial Presence Detect (SPD) EEPROM (used on DIMMs to store timing parameters and module specific information). It communicates with the CPU chipset through an I2C/SMBus-compatible serial bus. It is factory trimmed and calibrated, requiring no additional external components.  The SE97B operates on a supply voltage from 3.0 V to 3.6 V over a -40 to +125 °C temperature range with typical supply current at 3.3 V of 250 micro amps.

Features:

• JEDEC (JC-42.4) DIMM temperature sensor plus 256-byte serial EEPROM for Serial Presence Detect (SPD).
• SDA open-drain output design for best operation in distributed multi-point applications.
• Shutdown current: 0.1 µA (typ.) and 5.0 µA (max).
• Power-on reset: 1.8 V (typ).
• 2-wire interface: I2C-bus/SMBus compatible, 0 Hz to 400 kHz.
• SMBus Alert Response Address and TIMEOUT 25 ms to 35 ms (programmable).
• ESD protection exceeds 2500 V HBM per JESD22-A114, 250 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101.
• Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA.
• Available in HWSON8 package.

Applications:

• DDR2 and DDR3 memory modules.
• Laptops, personal computers and servers.
• Enterprise networking.
• Hard disk drives and other PC peripherals.

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