ST STTS3000 User Manual

STTS3000

2.3 V memory module temperature sensor

Features

■STTS3000 is a 2.3 V memory module temperature sensor forward compatible with JEDEC standard TS3000 and backward compatible with STTS424

■Operating temperature range:

––40 °C to +125 °C

■Single supply voltage: 2.3 V to 3.6 V

■Temperature sensor resolution: programmable (9-12 bits)

0.25 °C (typ)/LSB - (10-bit) default

■Temperature sensor accuracy (max):

–± 1 °C from +75 °C to +95 °C

–± 2 °C from +40 °C to +125 °C

–± 3 °C from –40 °C to +125 °C

Data brief

TDFN8 (DN)(a)

2 mm x 3 mm (max height 0.80 mm)

■2 mm x 3 mm TDFN8, height: 0.80 mm (max)(a)

■RoHS compliant, halogen-free

■ADC conversion time: 125 ms (max) at default resolution (10-bit)

■Typical operating supply current: 160 µA

■Temperature hysteresis selectable set points from: 0, 1.5, 3, 6.0 °C

■Two-wire SMBus/I2C - compatible serial interface

■Supports up to 400 kHz transfer rate

■Does not initiate clock stretching

■Supports SMBus timeout 25 ms - 35 ms

■Spike suppression filters on the two-wire bus inputs

■Voltage hysteresis per I2C specs on the twowire bus inputs

a. Compliant to JEDEC MO-229, WCED-3

April 2010	Doc ID 17407 Rev 1	1/8
For further information contact your local STMicroelectronics sales office.		www.st.com

Description	STTS3000

1 Description

The STTS3000 is targeted for DIMM modules in mobile personal computing platforms (laptops), servers and other industrial applications. The thermal sensor (TS) in the STTS3000 is compliant with the JEDEC specification TS3000 which defines memory module thermal sensors requirements for mobile platforms.

The TS provides space as well as cost savings for mobile and server platform dual inline memory modules (DIMM) manufacturers, as it is packaged in the compact 2 mm x 3 mm 8-lead TDFN package with a thinner maximum height of 0.80 mm. The DN package is compliant to JEDEC MO-229, variation WCED-3.

The digital temperature sensor has a programmable 9-12 bit analog-to-digital converter (ADC) which monitors and digitizes the temperature to a resolution of up to 0.0625 °C. The default resolution is 0.25 °C/LSB (10-bit). The typical accuracies over these temperature ranges are:

●±2 °C over the full temperature measurement range of –40 °C to 125 °C

●±1 °C in the +40 °C to +125 °C active temperature range, and

●±0.5 °C in the +75 °C to +95 °C monitor temperature range

The temperature sensor in the STTS3000 is specified for operating at supply voltages from 2.3 V to 3.6 V. Operating at 3.3 V, the typical supply current is 160 µA (includes SMBus communication current).

The on-board sigma delta ADC converts the measured temperature to a digital value that is calibrated in °C. For Fahrenheit applications, a lookup table or conversion routine is required. The STTS3000 is factory-calibrated and requires no external components to measure temperature.

The digital temperature sensor has user-programmable registers that provide the capabilities for DIMM temperature-sensing applications. The open drain event output pin is active when the monitoring temperature exceeds a programmable limit, or it falls above or below an alarm window. The user has the option to set the event output as a critical temperature output. This pin can be configured to operate in either a comparator mode for thermostat operation or in interrupt mode.

2/8	Doc ID 17407 Rev 1

STTS3000										Description
	Figure 1. Logic diagram
						VDD
			SDA(1)							(1)
									EVENT
			SCL			STTS3000
			A2
			A1
			A0
						VSS
										AI12261

1. SDA and EVENT are open drain.

Table 1.			Signal names
Pin			Symbol			Description	Type
1			A0			Serial bus address selection pin. Can be tied to VSS or VDD.	Input
2			A1			Serial bus address selection pin. Can be tied to VSS or VDD.	Input
3			A2			Serial bus address selection pin. Can be tied to VSS or VDD.	Input
4			VSS			Supply ground
5			SDA(1)			Serial data	Input/output
6			SCL			Serial clock	Input
7					(1)	Event output pin. Open drain and active-low.	Output
			EVENT
8			VDD			Supply power (2.3 V to 3.6 V)

1. SDA and EVENT are open drain.

Figure 2. TDFN8 connections (top view)

A0	1	8		VDD
A1	2	7			(1)
				EVENT
A2	3	6		SCL
GND	4	5		SDA(1)

AI12262

1. SDA and EVENT are open drain.

Doc ID 17407 Rev 1

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