DS1616

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DESCRIPTION

The DS1616 is an integrated temperature/data recorder.

It combines a Real Time Clock (RTC),

temperature sensor, and a three input mux’ed 8-bit Analog-to-Digital Converter (ADC). Datalogging is

supported for all four data channels and the and histogram functionality is supported for the temperature

sensor and ADC Channel 1 only. A programmable sample rate feature makes the device ideal for

applications requiring datalogging over short or long time frames.

The RTC provides seconds, minutes, hours, day, date, month, and year information with leap year

compensation, Year 2000 compliance, and also provides an alarm interrupt. Temperature measurement is

provided via integrated thermal technology which can measure temperatures from -40

°C to +85°C in

0.5

°C increments. An integrated three input mux’ed 8-bit ADC allows the device to record data from

other types of sensors.

The datalog function simply samples data at a user-defined sample rate and writes the data to the Datalog

memory. A total of 2048 bytes of data may be recorded. If only one data channel is selected, a total of

2048 samples can be recorded for that channel. If two channels are enabled, each channel can record

1024 samples. If three or four channels are enabled, each channel can record 512 samples. In the case of

only three channels enabled, the location corresponding to the disabled channel will be 0 to allow the roll-

over function to work smoothly.

Histogram functionality is provided for the Thermal Sensor and ADC Channel 1, and is implemented by

sampling the data and then incrementing the count value in a data bin associated with that value. The

DS1616 provides 63 2-byte data bins in 2

°C increments for the temperature channel and 64 2-byte data

bins in 4-bit resolution steps (32mV/bin) for the ADC Data Channel 1. The sampling rate can be

programmed at intervals ranging from once per minute to once every 255 minutes.

The DS1616 provides programmable high- and low-temperature alarm trip points that allow the device to

monitor whether the temperature stays within desired limits. Likewise, high- and low- trip points can be

programmed for the ADC data. The device can drive an interrupt or status pin if the ADC data falls

outside of the programmable limits. The Temperature Sensor and Channel 1 of the ADC can also have

any event that falls outside of the programmed limits recorded with a time and date stamp and the

duration of the out-of-limits condition for additional analysis in the Alarm Memory. The DS1616 can be

programmed to begin sampling data via a pushbutton input or via a command sent over the serial

interface by a host machine.

A 64-bit serial number is available for unique product identification and tracking.

OVERVIEW

The block diagram in Figure 1 shows the relationship between the major control and memory sections of

the DS1616. The device has six major data components: 1) Real Time Clock and control blocks, 2)

32-byte User NV RAM with 64-bit lasered serial number, 3) 96 bytes of alarm event/duration memory, 4)

128 bytes of temperature histogram RAM, 5) 128 bytes of ADC Channel 1 data histogram RAM, and 6)

2048 bytes of datalog memory. All memory is arranged in a single linear address space.