DESCRIPTION
The DS1780E is a highly integrated system instrumentation monitor ideal for use in personal computers, or any microprocessor-based system. It monitors ambient temperature, six power supply voltages, and the speed of two fans. Fan speed can also be controlled with the use of an internal 8-bit DAC. All measurements are internally converted to a digital format for easy processing by the CPU.
The DS1780E can be reset to its default power-up state via a remote reset function with internal debounce and delay. It features an interrupt that can be programmed to become active should any of the functions the DS1780E is monitoring fall out of spec.
For board-level testability, an internal NAND TREE function simplifies the system design. A chassis intrusion input is featured to enhance system security.
Programming and data readout are accessed via a simple 2-wire interface with 2-bit addressability. The DS1780E power supply range of 2.8V to 5.75V allows for monitoring of parameters for 3V or 5V systems. The DS1780E is assembled in a compact 173-mil TSSOP package.
FEATURES
Direct-to-digital temperature sensor requires no external components or user calibration
Two fan speed sensors
Monitors 6 power supply voltages
8-bit DAC for fan speed control
Intrusion detect for security (detects when chassis lid has been removed, even if power is off)
Remote system reset
System interrupt availability on all monitored functions (temperature, voltages, fan speed,chassis intrusion)
2-wire interface with 2-bit addressability
Integrated NAND TREE for board level testability
Wide power supply range (2.8V ≤ VDD ≤5.75V)
High integration in a small 24-pin 173-mil TSSOP
Applications include monitoring of personal computers or any microprocessor-based system
Feature
- ±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)
Applications
- Computer Graphics Systems
- Industrial Instruments
- Notebook Computers
- Portable Terminals
- Storage Area Networks (SANs)
(Picture: Pinout)
