LM91 Datasheet | National Semiconductor

Description The LM91 is a remote diode temperature sensor, Delta-Sigma analog-to-digital converter, and digital over-temperature detector with an SMBus™ interface. The LM91 senses its own temperature as well as the temperature of a target IC with a diode junction, such as a Pentium® II processor or a diode connected 2N3904. A diode junction (semiconductor junction) is required on the target IC’s die. A host can query the LM91 at any time to read the temperature of this diode as well as the temperature state of the LM91 itself. A T_CRIT_A interrupt output bees active when the temperature is greater than a programmable parator limit, T_CRIT. The host can program as well as read back the state of the T_CRIT register. Power up default values for T_CRIT are as shown in the ordering information table. Three state logic inputs allow two pins (ADD0, ADD1) to select up to 9 SMBus address locations for the LM91. Features n Directly senses die temperature of remote ICs n Senses temperature of remote diodes n SMBus patible interface, supports SMBus Timeout n Register readback capability n 7 bit plus sign temperature data format n 2 address select lines enable 9 LM91s to be connected to a single bus Key Specifications j Supply Voltage j Supply Current j Local Temperature Accuracy j Remote Diode Temperature Accuracy +60˚C to +100˚C 0˚C to +125˚C 3.0V - 3.6V 1 m A (max) ±1.0˚C (typ) ±4˚C (max) ±6˚C (max) Applications n System Thermal Management n Personal puters n Electronic Test Equipment n Office Electronics n HVAC Simplified Block Diagram # Indicates Active Low (”NOT“) SMBus™ is a trademark of the Intel Corporation. Pentium® II processor is a registered trademark of the Intel Corporation. I2C® is a registered trademark of the Philips Corporation. © 2001 National Semiconductor Corporation DS200343 .national. Connection Diagram QSOP-16 TOP VIEW Ordering Information Order Number LM91DIMQA LM91DIMQAX NS Package Number Transport Media MQA16A...