SE98A

General description

The NXP Semiconductors SE98A measures temperature from -40 Cel and +125 Cel with JEDEC Grade B +-1 Cel accuracy between +75 Cel and +95 Cel communicating via the I²C-bus/SMBus. It is typically mounted on a Dual In-Line Memory Module (DIMM) measuring the DRAM temperature in accordance with the new JEDEC (JC-42.4) Mobile Platform Memory Module Thermal Sensor Component specification.

The SE98A thermal sensor operates over the V_DD 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 Temp Sensor (TS) consists of an Analog-to-Digital Converter (ADC) that monitors and updates its own temperature readings 8 times per second, converts the reading to a digital data, and latches them into the data temperature registers. User-programmable registers, such as Shutdown or Low-power modes and the specification of temperature event and critical output boundaries, provide flexibility for DIMM temperature-sensing applications.

When the temperature changes beyond the specified boundary limits, the SE98A 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 even be configured as a critical temperature output.

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 is an improved SE98 and is comparable to the thermal sensor in the SE97 but with voltage range of 1.7 V to 3.6 V.

Features

• JEDEC (JC-42.4) TS3000B1 DIMM +- 0.5 Cel (typ.) between 75 Cel and 95 Cel temperature sensor
• Optimized for voltage range: 1.7 V to 3.6 V
• Shutdown current: 0.1 uA (typ.) and 5.0 uA (max.)
• 2-wire interface: I²C-bus/SMBus compatible, 0 Hz to 400 kHz
• SMBus ALERT and TIMEOUT (programmable)
• 11-bit ADC Temperature-to-Digital converter with 0.125 Cel resolution
• Operating current: 250 uA (typ.) and 400 uA (max.)
• Programmable hysteresis threshold: 0 Cel, 1.5 Cel, 3 Cel, 6 Cel
• Over/under/critical temperature EVENT output
• B grade accuracy:
  • +-0.5 Cel/+-1 Cel (typ./max.) → +75 Cel to +95 Cel
  • +-1 Cel/+-2 Cel (typ./max.) → +40 Cel to +125 Cel
  • +-2 Cel/+-3 Cel (typ./max.) → -40 Cel to +125 Cel
• ESD protection exceeds 2000 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 packages: TSSOP8, HWSON8 (PSON8 VCED-3) and HXSON8

Products/packages

Quality/reliability/chemical content

Quality and reliability disclaimer

Pricing/ordering/availability

Applications

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

Related applications
Intelligent washing machine
Transceiver board
Power amplifier board
Main CPU board
LCD TV - MMS functionality

Block diagrams/pinning

Design support

Application Notes

AN10216; I2C manual (2003-03-27)

AN10441; Level shifting techniques in I2C-bus design (2007-06-20)

Support Documents

UM10206; I2C Demonstration Board 2005-1 Quick Start Guide (2006-06-13)

UM10204; I2C-bus specification and user manual (2007-06-26)

web; IBIS and HSPICE Model ()

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer