ZHCSEK6A January 2015 – September 2018 TPL5010
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 器件比较表
- 6 Pin Configuration and Functions
- 7 Specifications
- 8 Detailed Description
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文档支持
- 13机械、封装和可订购信息
8.5.3 Timer Interval Selection Using External Resistance
To set the time interval, the external resistance REXT is selected according to Equation 1:
Equation 1. 
where
- T is the desired time interval in seconds.
- REXT is the resistance value to use in Ω.
- a, b, and c are coefficients depending on the range of the time interval.
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.
Equation 2. 
The resistance value is 10.18 kΩ.
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 |
| 1min | 22.02 | 22.021 | 40.2 // 48.7 |
| 2min | 29.35 | 29.349 | 35.7 // 165.0 |
| 3min | 34.73 | 34.729 | 63.4 // 76.8 |
| 4min | 39.11 | 39.097 | 63.4 // 102.0 |
| 5min | 42.90 | 42.887 | 54.9 // 196.0 |
| 6min | 46.29 | 46.301 | 75.0 // 121.0 |
| 7min | 49.38 | 49.392 | 97.6 // 100.0 |
| 8min | 52.24 | 52.224 | 88.7 // 127.0 |
| 9min | 54.92 | 54.902 | 86.6 // 150.0 |
| 10min | 57.44 | 57.437 | 107.0 // 124.0 |
| 20min | 77.57 | 77.579 | 140.0 // 174.0 |
| 30min | 92.43 | 92.233 | 182.0 // 187.0 |
| 40min | 104.67 | 104.625 | 130.0 // 536.00 |
| 50min | 115.33 | 115.331 | 150.0 // 499.00 |
| 1h | 124.91 | 124.856 | 221.0 // 287.00 |
| 1h30min | 149.39 | 149.398 | 165.0 // 1580.0 |
| 2h | 170.00 | 170.00 | 340.0 // 340.0 |