| No | Part number | Description ( Function ) | Manufacturers | |
| 21 | BQ29401 | Voltage Protection for 2-3-or4-Cell Lion Batteries (Rev. C) |
 Texas Instruments |
|
| 20 | BQ29410 | Voltage Protection for 2- 3- or 4-Cell Li-Ion Batteries (2nd Level Protection) (Rev. G) |
Texas Instruments |
|
| 19 | BQ29449 | Voltage Protection For Two- Three- or Four-Cell Li-Ion Batteries (Rev. C) |
Texas Instruments |
|
| 18 | BQ2945 | Gas Gauge IC With SMBus Interface |
Texas Instruments |
|
| 17 | BQ294502 | bq2945xx Overvoltage Protection For 2-Series and 3-Series Cell Li-Ion Batteries (Rev. D) |
Texas Instruments |
|
| 16 | BQ294504 | bq2945xx Overvoltage Protection For 2-Series and 3-Series Cell Li-Ion Batteries (Rev. D) |
Texas Instruments |
|
List of most widely used semiconductors
| Part Number | Function | Manufacturers | |
| 1N4007 | The 1N4007 is a rectification diode that is designed for high-voltage applications, typically up to 1000V. It has a maximum current rating of 1A and a forward voltage drop of around 0.7V. |
 Vishay |
|
| LM317 | This is a popular adjustable voltage regulator. |
 ON Semiconductor |
|
6N137 | LM393 | 2N3906 | 2N2222 | TIP120 | 1N5818 | LM324N | A1015 | SMAJ20CA |
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