TMP512 datasheet(29/62 Pages) TI2

29 / 62 page

MaxPossible_I=

SHUNT_MAX

SHUNT

MaxPossible_I=0.064

Minimum_LSB=

Max_Expected_I

32767

Minimum_LSB=1.831

-6

Maximum_LSB =

Max_Expected_I

4095

Maximum_LSB = 14.652

-6

Cal=trunc

0.04096

Current_LSB

SHUNT

Cal=4311

Power_LSB=20Current_LSB

Power_LSB=38

-6

TMP512

TMP513

www.ti.com

SBOS491A

– JUNE 2010 – REVISED MAY 2011

Calibration Example 2 (Overflow Possible)

This design example uses the nine-step procedure for calibrating the TMP512/13 where overflow is possible.

Figure 33 illustrates how the same procedure is performed using the automated TMP512/13EVN software. The

same numbers used in the nine-step example are used in the software example shown in Figure 33. Note also

that Figure 33 illustrates which results correspond to which step (for example, the information entered in Step 1

is circled in Figure 33 and labeled).

1. Establish the following parameters:

VBUS_MAX = 32

VSHUNT_MAX = 0.32

RSHUNT = 5

2. Determine the maximum possible current using Equation 15:

(15)

3. Choose the desired maximum current value: Max_Expected_I,

≤ MaxPossible_I. This value is selected

based on system expectations.

Max_Expected_I = 0.06

4. Calculate the possible range of current LSBs. This calculation is done by first computing a range of LSB's

that is appropriate for the design. Next, select an LSB withing this range. Note that the results will have the

most resolution when the minimum LSB is selected. Typically, an LSB is selected to be the nearest round

number to the minimum LSB.

(16)

(17)

Choose an LSB in the range: Minimum_LSB

< Selected_LSB < Maximum_LSB

Current_LSB = 1.9

× 10–6

Note:

This value was selected to be a round number near the Minimum_LSB. This section allows for good

resolution with a rounded LSB.

5. Compute the calibration register using Equation 18:

(18)

6. Calculate the Power LSB using Equation 19. Equation 19 shows a general formula; because the bus voltage

measurement LSB is always 4mV, the power formula reduces to calculate the result.

(19)

TMP512 Datenblatt(PDF) 29 Page - Texas Instruments

TMP512 Datenblatt(HTML) 29 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62

Datenblatt Download

Link URL