The document describes a direct-to-digital temperature sensor that requires no external components or user calibration. It also features two fan speed sensors, monitors 6 power supply voltages, an 8-bit DAC for fan speed control, intrusion detect for security, remote system reset, and system interrupt availability on all monitored functions.
The DS1780 is a highly integrated system instrumentation monitor designed for personal computers and other microprocessor‑based systems. It measures ambient temperature, six power‑supply voltages, and two fan speeds, and can control fan speed via an internal 8‑bit DAC. All measurements are converted to digital format for easy CPU processing.
Communication with the device uses a simple 2‑wire serial bus with 2‑bit addressability. The DS1780 includes a chassis intrusion detector, remote reset, and programmable interrupt output. Electrical specifications, pin assignments, and register maps are provided for hardware designers and firmware developers.
| Power supply voltage range | 2.8 V to 5.75 V |
|---|---|
| Number of analog inputs | 6 |
| Number of fan speed inputs | 2 |
| Temperature resolution | 0.5 °C per LSB |
| DAC resolution for fan control | 8‑bit |
| Interface type | 2‑wire serial bus with 2‑bit addressability |
| Package | 24‑pin TSSOP (173‑mil) |
| Operating temperature range | -40 °C to +125 °C |
The DS1780 operates from 2.8 V up to 5.75 V.
It provides two fan speed inputs.
Temperature is output as a two’s‑complement 9‑bit value with a 0.5 °C LSB.
The default address is binary 01011(A1)(A0).