SE97BTP

DDR内存模块温度传感器集成SPD DDR memory module temp sensor with integrated SPD

Overview

Meets JEDEC Specification 42.4 TSE2002B1, 3 Jun 2009. The ® Semiconductors SE97B measures temperature from -40 °C to +125 °C with JEDEC Grade B ±1 °C maximum accuracy between +75 °C and +95 °C critical zone and also provide 256 bytes of EEPROM memory communicating via the I2C-bus/SMBus. It is typically mounted on a DDR3 Dual In-Line Memory Module DIMM measuring the DRAM temperature in accordance with the new JEDEC JC-42.4 Mobile Platform Memory Module Temperature Sensor Component specification and also replacing the Serial Presence Detect SPD which is used to store memory module and vendor information.

The SE97B thermal sensor and EEPROM operates over the VDD range of 3.0 V to 3.6 V.

The TS consists of a Δ∑ Analog to Digital Converter ADC that monitors and updates its own temperature readings 10 times per second, converts the reading to a digital data, and latches them into the data temperature register. User-programmable registers, the specification of upper/lower alarm and critical temperature trip points, EVENT output control, and temperature shutdown, provide flexibility for DIMM temperature-sensing applications.

When the temperature changes beyond the specified boundary limits, the SE97B outputs an EVENT signal using an open-drain output that can be pulled up between 0.9 V and 3.6 V. 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 only a critical temperature output.

The EEPROM is designed specifically for DRAM DIMMs SPD. The lower 128 bytes address 00h to 7Fh can be Permanent Write Protected PWP or Reversible Write Protected RWP by software. This allows DRAM vendor and product information to be stored and write protected. The upper 128 bytes address 80h to FFh are not write protected and can be used for general purpose data storage.

The SE97B has a single die for both the temp sensor and EEPROM for higher reliability and 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 identity of the device. Three address pins allow up to eight devices to be controlled on a single bus.

The SE98B is available as the SE97B thermal sensor only.

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## Features

**2.1 General 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

**2.2 Temperature sensor features**

* 11-bit ADC Temperature-to-Digital converter with 0.125 °C resolution

* Voltage range: 3.0 V to 3.6 V

* Operating current: 250 µA typ. and 400 µA max.

* Programmable hysteresis threshold: off, 0 °C, 1.5 °C, 3 °C, 6 °C

* Over/under/critical temperature EVENT output

* B-grade accuracy:

* ±0.5 °C/±1 °C typ./max. ? +75 °C to +95 °C

* ±1.0 °C/±2 °C typ./max. ? +40 °C to +125 °C

* ±2.0 °C/±3 °C typ./max. ? -40 °C to +125 °C

**2.3 Serial EEPROM features**

* Read and write voltage range: 3.0 V to 3.6 V

* Operating current:

* Write → 0.6 mA typ. for 3.5 ms typ.

* Read → 100 µA typ.

* Organized as 1 block of 256 bytes 256 × 8

* 100,000 write/erase cycles and 10 years of data retention

* Permanent and Reversible Software Write Protect

* Software Write Protection for the lower 128 bytes

## Target Applications

* DDR2 and DDR3 memory modules

* Laptops, personal computers and servers

* Enterprise networking

* Hard disk drives and other PC peripherals

## Features