CPU Peripheral Monitor

The DS1780 is a highly integrated system instrumentation monitor that is ideal for use in personal computers or any microprocessor-based system. It monitors temperature (±2°C accuracy from -25°C to +100°C), six power supply voltages, and the speed of two fans. Fan speed can also be controlled using the DS1780's internal 8-bit DAC. All measurements are internally converted to a digital format for easy processing by the CPU.

The DS1780 can be reset to its default power-up state through a remote reset function that has internal debounce and delay. The DS1780 also features an interrupt function that can be programmed to become active should any of the monitored parameters fall out of spec. For board-level testability, an internal NAND TREE function simplifies system design, and a chassis intrusion input enhances system security.

Programming and data readout are accessed through a simple 2-wire interface with 2-bit addressability. The DS1780 power supply range of 2.8V to 5.75V allows parameter monitoring for 3V or 5V systems. The DS1780 is assembled in a 24-pin 173mil TSSOP package (DS1780E).

Applications

* Computer Graphics Systems * Industrial Instruments * Notebook Computers * Portable Terminals * Storage Area Networks (SANs)

* ±2°C accuracy (from -25°C to +100°C) 9-bit digital thermometer

* Six 8-bit ADC channels for monitoring PC power supplies

* Two tachometer inputs

* 8-bit DAC for fan speed control

* Maskable system interrupt for all measured parameters (temperature, voltage, fan speed, intrusion detect)

* Limit settings are user-programmable

* Data is transferred over 2-wire/SMBus interface

* Two address inputs allow up to four DS1780 to operate on a single bus

* 2.8V to 5.75V operating range

* 24-pin 173mil TSSOP package (DS1780E)