SE98A Datasheet, PDF (1/43 Pages) NXP Semiconductors – DDR memory module temp sensor, 1.7 V to 3.6 V

SE98A
DDR memory module temp sensor, 1.7 V to 3.6 V
Rev. 02 — 6 August 2009
Product data sheet
1. General description
The NXP Semiconductors SE98A measures temperature from −40 °C and +125 °C with
JEDEC Grade B ±1 °C accuracy between +75 °C and +95 °C 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.
2. Features
I JEDEC (JC-42.4) TS3000B1 DIMM ± 0.5 °C (typ.) between 75 °C and 95 °C
temperature sensor
I Optimized for voltage range: 1.7 V to 3.6 V
I Shutdown current: 0.1 µA (typ.) and 5.0 µA (max.)
I 2-wire interface: I²C-bus/SMBus compatible, 0 Hz to 400 kHz
I SMBus ALERT and TIMEOUT (programmable)
I 11-bit ADC Temperature-to-Digital converter with 0.125 °C resolution