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.