1FEATURES

2• Accurately Senses Die Temperature of Remote

ICs or Diode Junctions

• Remote Diode Fault Detection

• On-board Local Temperature Sensing

• Remote Temperature Readings

– 0.125°C LSb

– 10-bits Plus Sign or 11-bits Programmable

Resolution

– 11-bits Resolves Temperatures Above

127°C

• Local Temperature Readings

– 0.25°C

– 9-bits Plus Sign

• Status Register Support

• Programmable Conversion Rate Allows User

Optimization of Power Consumption

• Shutdown Mode One-shot Conversion Control

• SMBus 2.0 Compatible Interface, Supports

TIMEOUT

• 8-pin VSSOP Package

KEY SPECIFICATIONS

• Local Temperature Accuracy

– TA = 0°C to 85°C ± 3.0°C (max)

• Remote Diode Temperature Accuracy

– TA = 30°C to 50°C, TD = 45°C to 85°C

±1.0 °C (Max)

– TA = 0°C to 85°C, TD = 25°C to 140°C

±3.0°C (Max)

• Supply Voltage 3.0 V to 3.6 V

• Supply Current 2 mA (Typ)

APPLICATIONS

• Processor/Computer System Thermal

Management (e.g. Laptop, Desktop,

Workstations, Server)

• Electronic Test Equipment

• Office Electronics

DESCRIPTION

The LM95221 is a dual remote diode temperature sensor in an 8-lead VSSOP package. The 2-wire

serial interface of the LM95221 is compatible with

SMBus 2.0. The LM95221 can sense three

temperature zones, it can measure the temperature

of its own die as well as two diode connected

transistors. The diode connected transistors can be a

thermal diode as found in Pentium and AMD

processors or can simply be a diode connected

MMBT3904 transistor. The LM95221 resolution format for remote temperature readings can be

programmed to be 10-bits plus sign or 11-bits

unsigned. In the unsigned mode the LM95221 remote

diode readings can resolve temperatures above

127°C. Local temperature readings have a resolution

of 9-bits plus sign.

The temperature of any ASIC can be accurately

determined using the LM95221 as long as a

dedicated diode (semiconductor junction) is available

on the target die. The LM95221 remote sensor

accuracy of ±1°C is factory trimmed for a series

resistance of 2.7 ohms and 1.008 non-ideality factor.