¸

¸

¹

·

¨

¨

©

§

1284

.

0

*

2

8

*

100

8889

.

2561

1284

.

0

*

4

9861

.

46

9861

.

46

100

2

EXT

R

13

TPL5010

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SNAS651A – JANUARY 2015 – REVISED SEPTEMBER 2018

Product Folder Links: TPL5010

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Copyright © 2015–2018, Texas Instruments Incorporated

Programming (continued)

Table 1. Coefficients for Equation 1

SET

Time interval

Range (s)

a

b

c

1

1 < T

≤ 5

0.2253

–20.7654

570.5679

2

5 < T

≤ 10

–0.1284

46.9861

–2651.8889

3

10 < T

≤ 100

0.1972

–19.3450

692.1201

4

100 < T

≤ 1000

0.2617

–56.2407

5957.7934

5

T > 1000

0.3177

–136.2571

34522.4680

EXAMPLE

Required time interval: 8 s

The coefficient set to be selected is the number 2. The formula becomes Equation 2.

(2)

The resistance value is 10.18 k

Ω.

Table 2 and Table 3 contain example values of tIP and their corresponding value of REXT.

Table 2. First 9 Time Intervals

tIP (ms)

Resistance (Ω)

Closest Real Value (Ω)

Parallel of Two 1% Tolerance

Resistors, (kΩ)

100

500

500

1.0 // 1.0

200

1000

1000

-

300

1500

1500

2.43 // 3.92

400

2000

2000

-

500

2500

2500

4.42 // 5.76

600

3000

3000

5.36 // 6.81

700

3500

3500

4.75 // 13.5

800

4000

4000

6.19 // 11.3

900

4500

4501

6.19 // 16.5

Table 3. Most Common Time Intervals Between 1s to 2h

tIP

Calculated Resistance (kΩ)

Closest Real Value

(kΩ)

Parallel of Two 1% Tolerance Resistors,

(kΩ)

1s

5.20

5.202

7.15 // 19.1

2s

6.79

6.788

12.4 // 15.0

3s

7.64

7.628

12.7// 19.1

4s

8.30

8.306

14.7 // 19.1

5s

8.85

8.852

16.5 // 19.1

6s

9.27

9.223

18.2 // 18.7

7s

9.71

9.673

19.1 // 19.6

8s

10.18

10.180

11.5 // 8.87

9s

10.68

10.68

17.8 // 26.7

10s

11.20

11.199

15.0 // 44.2

20s

14.41

14.405

16.9 // 97.6

30s

16.78

16.778

32.4 // 34.8

40s

18.75

18.748

22.6 // 110.0

50s

20.047

20.047

28.7 // 66.5