DS1624 Maxim Integrated Products, DS1624 Datasheet
DS1624
Specifications of DS1624
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DS1624 Summary of contents
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... DIP or SOIC packages DESCRIPTION The DS1624 consists of a digital thermometer and 256 bytes of E 13-bit temperature readings which indicate the temperature of the device. The E store frequency compensation coefficients for digital correction of crystal frequency due to temperature. Any other type of information may also reside in this user space. ...
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... Supply Voltage 2.7V to 5.5V input power pin. DD OVERVIEW A block diagram of the DS1624 is shown in Figure 1. The DS1624 consists of two separate functional units 256–byte nonvolatile E The nonvolatile memory is made up of 256 bytes of E type of information the user wishes; for example, frequency compensation coefficients may be placed in this memory to allow for compensation of measured frequency depending upon the temperature at which the measurement is made. These memory locations are accessed through the 2– ...
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... START and STOP conditions. The DS1624 operates as a slave on the two–wire bus. Connections to the bus are made via the open–drain I/O lines SDA and SCL. The following bus protocol has been defined (See Figure 2): • ...
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... Within the bus specifications a regular mode (100 KHz clock rate) and a fast mode (400 KHz clock rate) are defined. The DS1624 works in both modes. Acknowledge: Each receiving device, when addressed, is obliged to generate an acknowledge after the reception of each byte. The master device must generate an extra clock pulse which is associated with this acknowledge bit ...
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... A control byte is the first byte received following the START condition from the master device. The control byte consists of a four bit control code; for the DS1624, this is set as 1001 binary for read and write operations. The next three bits of the control byte are the device select bits (A2, A1, A0). They are used by the master device to select which of eight devices are to be accessed ...
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... OPERATION-MEASURING TEMPERATURE A block diagram of the DS1624 is shown in Figure 1. The DS1624 measures temperatures through the use of an on–board proprietary temperature measurement technique. A block diagram of the temperature measurement circuitry is shown in Figure 4. The DS1624 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 – ...
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... Since data is transmitted over the 2–wire bus MSB first, temperature data may be written to/read from the DS1624 as either a single byte (with temperature resolution of 1° two bytes, the second byte containing the value of the 5 least significant bits of the temperature reading as shown in Table 1. Note that the remaining three bits of this byte are set to all 0’ ...
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... LOW, are placed onto the bus by the master. The master then sends the Access Memory protocol. This indicates to the addressed DS1624 that a byte with a word address will follow after it has generated an acknowledge bit. Therefore, the next byte transmitted by the master is the word address and will be written into the address pointer of the DS1624 ...
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... COMMAND SET Data and control information is read from and written to the DS1624 in the format shown in Figure 3. To write to the DS1624, the master will issue the slave address of the DS1624 and the R/ “ ...
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... This command stops temperature conversion. No further data is required. This command may be used to halt a DS1624 in continuous conversion mode. After issuing this command, the current temperature measurement will be completed then the DS1624 will remain idle until a Start Convert T is issued to resume continuous operation. ...
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... During the programming cycle the DS1624 will not acknowledge any further accesses to the device until the programming cycle is complete (approximately 10 ms). MEMORY FUNCTION EXAMPLE BUS MASTER DS1624 MODE MODE {Command protocol for configuration register} {Start here {Command protocol for Start Convert T} ...
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... ACK DS1624 generates acknowledge bit. START Bus Master initiates a Repeated Start condition. <cadr,1> Bus Master sends DS1624 address; R/ =1; W ACK DS1624 generates acknowledge bit. <data> DS1624 sends the first byte of data. ACK Bus Master generates acknowledge bit COMMENTS DS1624 NOTES ...
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... If this protocol follows a write and the DS1624 does not acknowledge here, restart the protocol at the Start here does acknowledge, continue on. 2. Wait for write to complete (10 ms typ max). If DS1624 does not acknowledge the command protocol immediately following a configure register or write mem protocol, the DS1624 has not finished writing ...
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... OL2 current 0.4<V -10 I/O <0. I/O I Temperature CC Coversion 2 E Write Communica- tion Only I STBY MAX UNITS 5.5 V =2.7V to 5.5V) DD TYP MAX UNITS ±½ °C See Typical Curve 0.6 V +10 µ 1000 400 µA 100 1 3 µA DS1624 NOTES 1 NOTES ...
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... Standard Mode Fast Mode 0.6 Standard Mode 4.0 and V =0 =2.7V to 5.5V) DD TYP MAX UNITS 400 1000 50k writes 20 years 400 kHz 100 µs µs µs µs µs 0.9 µs ns 300 ns B 1000 300 ns B 300 µs 400 pF DS1624 NOTES ...
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... See Typical Curve for specification limits outside the 0°C to 70°C temperature range. Thermometer error reflects sensor accuracy as tested during calibration. (-55°C to +125°C; V SYMBOL MIN 1000+250 = 1250 ns before the SCL line is released. SU:DAT =2.7V to 5.5V) DD TYP MAX UNITS switched off. DD LOW >250 ns must SU:DAT DS1624 NOTES ) of the ...
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... TIMING DIAGRAM Note: The DS1624 does not delay the SDA line internally with respect to SCL for any length of time TYPICAL PERFORMANCE CURVE DS1624 DIGITAL THERMOMETER AND THERMOSTAT TEMPERATURE READING ERROR TEMPERATURE (deg DS1624 t SP ...