DS1848E-050 查看數據表（PDF） - Maxim Integrated

零件编号

产品描述 (功能)

生产厂家

DS1848E-050

Dual Temperature-Controlled NV Variable Resistor & Memory

Maxim Integrated 

PROGRAMMING THE LOOK-UP TABLE (LUT)

DS1848

The following equation can be used to determine which resistor position setting, 00h – FFh, should be

written in the LUT to achieve a given resistance at a specific temperature.

[ [ ] ] pos(a,

R, C )

=

R - u · 1 + v · (C - 25) + w · (C - 25)2

(x) · 1 + y · (C - 25) + z · (C - 25)2

-a

DS1848-050

a = 3.78964 for the 50kW resistor

a = 19.74866 for the 10kW resistor

DS1848-010

a = 8.394533 for both 10kW resistors

R = resistance desired at the output terminal

C = temperature in degrees Celsius

u, v, w, x, y, and z are calibration constants programmed into each of the corresponding look-up tables.

Their addresses and LSB values are given in Table 1 below. Resistor 1 variables are found in Look-Up

table 1 of the EEPROM, and Resistor 2 variables are found in Look-Up Table 2. After these values are

read, they should be overwritten with the appropriate temperature specific resistance settings. Copies of

these values can also be found in the User EEPROM memory.

LOOK-UP VARIABLE ADDRESSES Table1

Address in Variable LSB

LUT (HEX)

28 – 29

u

2-8

2A – 2B

v

10-6

2C – 2D

w

10-9

2E – 2F

x

2-8

30 – 31

y

10-7

32 – 33

z

10-10

When shipped from the factory, all other memory locations in the LUTs are programmed to FFh (except

bytes 00h-07h of Table 1 and 2 which may be factory programmed to values other than FFh).

Note: Memory locations 44h – 47h, which cover the temperature range (+96ºC to +102ºC), are outside

of the specified operating temperature range (-40ºC to +95ºC). However, the values stored in these

locations will act as valid resistance settings if the temperature exceeds +95ºC. Therefore, Dallas

Semiconductor recommends that the user program a resistance value into all LUT locations. Failure to do

so will result in the part being set to the default value.

6 of 17

Share Link: