DDR memory module temp sensor, 1.7 V to 3.6 V

Mounted on a Dual In-Line Memory Module (DIMM), the NXP Semiconductors SE98A measures temperature from -40 ºC and +125 ºC with JEDEC Grade B ±1 ºC accuracy between +75 ºC and +95 ºC communicating via the I2C-bus/SMBus. The SE98A thermal sensor operates over the VDD range of 1.7 V to 3.6 V. The SE98A does not include the 2 k SPD and is designed for custom DIMM where larger SPD is required.

The SE98A supports the industry-standard 2-wire I²C-bus/SMBus serial interface. The SMBus TIMEOUT function is supported to prevent system lock-ups. Manufacturer and Device ID registers provide the ability to confirm the identify of the device. Three address pins allow up to eight devices to be controlled on a single bus. The SE98A supports the industry-standard 2-wire I²C-bus/SMBus serial interface. The SMBus TIMEOUT function is supported to prevent system lock-ups. Manufacturer and Device ID registers provide the ability to confirm the identify of the device. Three address pins allow up to eight devices to be controlled on a single bus.

Block diagram: SE98APW, SE98ATL, SE98ATP

Block diagram: SE98APW, SE98ATL, SE98ATP

Why Used

  • SMBus ALERT and TIMEOUT (programmable)
  • 11-bit ADC Temperature-to-Digital converter with 0.125 ºC resolution
  • Programmable hysteresis threshold: 0 ºC, 1.5 ºC, 3 ºC, 6 ºC
  • Over/under/critical temperature EVENT output
  • Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA

Where Used

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

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