Dallas Semiconductor announced the DS1615 Temperature Recorder, a one-chip instrument for measuring temperature integrity and variability over time. The DS1615 integrates a Y2K-compatible real-time clock, digital thermometer, nonvolatile memory, control logic, and serial interface. The collected data are stored in both a traditional data log and a histogram for easy thermal distribution analysis.

Designers seeking an efficient, low-cost and accurate method to manage temperature-sensitive systems benefit from the DS1615's integrated functions and exceptionally simple programming: only a few RTC and control registers need to be programmed to begin data collection. This single-chip device also takes less board space and reduces the testing and inventory costs of discrete parts, while improving overall reliability.

The DS1615 can operate in a standalone system as a complete data logger for such uses as monitoring perishable products in transit, food handling and storage conditions, environmental conditions, expiration dates, collecting remote data, and performing environmental research.

Alternatively, in an embedded environment, the DS1615 does not consume system resources to monitor and record the temperature. The DS1615 can also track environmental conditions during system power-down or minimal power periods. The resulting data can be used in calibration, maintenance and warranty applications. For example, after tracking the hours a laser printer operates at a given temperature, the DS1615 can signal the user to change the toner cartridge. With the DS1615 embedded in a system , the real-time clock and temperature sensor are available to the system, eliminating the need for additional components.

Raymon Moyer, product manager for the DS1615, said, "Existing options for collecting and managing temperature data are cumbersome. To match the DS1615's performance, the designer would have to assemble the various discrete components, as well as write software to operate the logger and analyze the data. The DS1615 integrates all data logging functions on a single chip."

Moyer continued, "As a further unique feature, not only can the DS1615 present data as a straight log of time and temperature, it also generates a readout in the form of a histogram. A histogram gives the user a clear picture of the frequency of occurrence of a given temperature, which is vital to some applications."

The DS1615 gives the programmer control over multiple functions through both standard 3-wire synchronous and RS232 interfaces with a built-in CRC generator. Nonvolatile memory can record 2048 consecutive temperatures, which the user can program to start at specific times and be taken at selected rates. Alarms and interrupts can be programmed for user-determined out-of-spec conditions, including expiration dates and extreme temperatures. The separate histogram memory allows for longer term data collection and distribution analysis.

Knowing someone who is in the business of building and selling temperature loggers for various industrial applications, I understand the nature of the completed, existing, beast -- and it's a really cumbersome area of work and required skills. This part will reduce that complexity to virtually nothing and will probably allow OEMs to drive costs down to maybe $20 for a completed unit. That compares with the average $150 of existing systems. The manufacturers who bend in this new direction with a part like this from Dallas Semi will be the winners, as the use of loggers will dramatically increase with lower costs. In many installations, loggers tend to be installed as insurance policies, and when you can the lower the cost of coverage suddenly more places needing insurance are found and more policies are sold.

The addition of the histogram capability is a wonderful one: most current implementations require separate manipulation of the data to give a histogram display. The provision of alarms will also be a welcome hook for many users. However a number of users will probably want more than the 2048 temperature recordings that are provided for by the size of the on-chip non-volatile memory.