Product Details

describe:

The LM99 is an 11-bit remote diode temperature sensor with a 2-wire System Management Bus (SMBus) serial interface. The LM99 accurately measures: (1) its own temperature and (2) the temperature of remote diode-connected transistors, such as the 2N3904 or thermal diodes commonly found on Graphics Processing Units (GPUs), Computer Processing Units (CPUs or other ASICs). LM99 Remote The diode temperature sensor reduces the temperature of the remote ADSP-21160NCB-100 sensor by 16°C and operates at this transition temperature:

T actual diode junction = T LM99 + 16°C

Local temperature readings do not need to be offset.

The LM99 has an offset register that provides a method for precise matching to various thermal diodes.

The LM99 and LM99-1 have the same function, but the SMBus slave address is different. This allows one of each to be on the same bus at the same time.

The ALERT output is activated when any temperature exceeds the preprogrammed window set by the high and low temperature limit registers or exceeds the T_CRIT temperature limit. The activation of T_CRIT_A occurs when any temperature exceeds the programmed limit of T_CRIT.

characteristic:

●Accurately sense the temperature of the remote diode

Offset registers allow the use of various thermal diodes

●Onboard local temperature sensing

10-bit plus sign remote diode temperature data format, 0.125 °C resolution

●T_CRIT_A output useful for system shutdown

●ALERT output supports SMBus 2.0 protocol

●SMBus 2.0 compatible interface, supports timeout

●8-pin VSSOP package

Main Specifications:

●Power supply voltage 3.0V to 3.6V

● Supply current 0.8 mA (typ.)

● Local temperature accuracy (including quantization error)

○TA = 25°C to 125°C ±3.0°C (max)

●Remote diode temperature accuracy (including quantization error)

○TA = 30°C to 50°C, TD = 120°C to 140°C ±1.0°C (max)

○TA = 0°C to 85°C, TD = 25°C to 140°C ±3.0°C (max)

parameter:

Local Sensor Accuracy (Max) (+/- C): 3

Type: remote

Operating temperature range (°C): 0 to 85

Power supply voltage (Min) (V): 2.7

Interface type: I2C, SMBus

Power supply voltage (Max) (V): 5.5

Supply Current (Max) (uA): 1700

Temperature Resolution (Max) (Bits): 8

Features: One-click conversion, ALERT

Remote channel (#): 1

Address: 2