Electronic Components Datasheet Search |
|
DS2438Z Datasheet(PDF) 4 Page - Maxim Integrated Products |
|
DS2438Z Datasheet(HTML) 4 Page - Maxim Integrated Products |
4 / 29 page DS2438 4 of 29 OPERATION-MEASURING TEMPERATURE The DS2438 measures temperatures through the use of an on-board temperature measurement technique. The temperature reading is provided in a 13-bit, two’s complement format, which provides 0.03125 °C of resolution. Table 1 describes the exact relationship of output data to measured temperature. The data is transmitted serially over the 1-Wire interface. The DS2438 can measure temperature over the range of -55 °C to +125°C in 0.03125°C increments. For Fahrenheit usage, a lookup table or conversion factor must be used. Note that temperature is represented in the DS2438 in terms of a 0.03125 °C LSb, yielding the following 13-bit format. The 3 least significant bits of the Temperature Register will always be 0. The remaining 13 bits contain the two’s complement representation of the temperature in °C, with the MSb holding the sign (S) bit. See “Memory Map” section for the Temperature Register address location. Temperature Register Format Table 1 2-1 2-2 2-3 2-4 2-5 0 0 0 LSB MSb (unit = °C) LSb S 26 25 24 23 22 21 20 MSB TEMPERATURE DIGITAL OUTPUT (Binary) DIGITAL OUTPUT (Hex) +125°C 01111101 00000000 7D00h +25.0625°C 00011001 00010000 1910h +0.5°C 00000000 10000000 0080h 0°C 00000000 00000000 0000h -0.5°C 11111111 10000000 FF80h -25.0625°C 11100110 11110000 E6F0h -55°C 11001001 00000000 C900h OPERATION-MEASURING BATTERY VOLTAGE The on-board analog-to-digital converter (ADC) has 10 bits of resolution and will perform a conversion when the DS2438 receives a command protocol (Convert V) instructing it to do so. The result of this measurement is placed in the 2-byte Voltage Register. The range for the DS2438 ADC is 0 volt to 10 volt; this range is suitable for NiCd or NiMH battery packs up to six cells, and for lithium ion battery packs of two cells. The full-scale range of the ADC is scaled to 10.23 volt, resulting in a resolution of 10 mV. While the ADC has a range that extends down to 0 volt, it is important to note that the battery voltage can also be the supply voltage to the DS2438. As such, the accuracy of the ADC begins to degrade below battery voltages of 2.4 volt, and the ability to make conversions is limited by the operating voltage range of the DS2438. Voltage is expressed in this register in scaled binary format, as outlined in Table 2. Note that while codes exist for values below 2.4 volt, accuracy of the ADC and the limitation on the DS2438’s supply voltage make it unlikely that these values would be used in actual practice. See “Memory Map” section for the Voltage Register address location. |
Similar Part No. - DS2438Z |
|
Similar Description - DS2438Z |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |