Download the project Report
This project is the property of Mr. Omer Younis, student of Electronics Engineering at National University of Science ans Technology, Pakistan. Feel free to contact at firstname.lastname@example.org
Aim & Objective:
- With three thermal alarm outputs, the DS1620 can also act as a thermostat.
- THIGH is driven high if the DS1620’s temperature is greater than or equal to a user–defined temperature TH. TLOW is driven high if the DS1620’s temperature is less than or equal to a user–defined temperature TL.
- TCOM is driven high when the temperature exceeds TH and stays high until the temperature falls below that of TL.
- User–defined temperature settings are stored in non-volatile memory, so parts can be programmed prior to insertion in a system, as well as used in standalone applications without a CPU. Temperature settings and temperature readings are all communicated to/from the DS1620 over a simple 3–wire interface.
- The DS1620 measures temperature by counting the number of clock cycles that an oscillator with a low temperature coefficient goes through during a gate period determined by a high temperature coefficient oscillator.
- The counter is preset with a base count that corresponds to –55°C. If the counter reaches 0 before the gate period is over, the temperature register, which is also preset to the –55°C value, is incremented, indicating that the temperature is higher than –55°C.
- At the same time, the counter is then preset with a value determined by the slope accumulator circuitry. This circuitry is needed to compensate for the parabolic behaviour of the oscillators over temperature.
- The counter is then clocked again until it reaches 0. If the gate period is still not finished, then this process repeats itself.