Using P-channel MOSFETs to control power distribution is easy in theory. But when it comes to high voltage and high power, several problems begin to happen. Even for low voltage switching like 3.3V or 5V rails, isn’t it neat to use a single SOT packaged component instead of combination of P-channel MOSFET, N-channel MOSFET and resistors?
3.3V or 5V Supply Voltage Management for Partial ON/OFF of Circuit Parts
| Part # | Manufacturer | Voltage (V) | Current (A) | Active on | Package | Price ($) |
| AP2552(A) | Diodes | 2.7~5.5 | 2.1 | Low | SOT26 | 0.2 |
| AP2553(A) | Diodes | 2.7~5.5 | 2.1 | High | SOT26 | 0.2 |
| RT9742CGJ5 | Richtek | 2.7~5.5 | 2 | High | TSOT-23-5 | 0.2 |
| TPS2051B | TI | 2.7~5.5 | 0.5 | High | SOT-23-5 | 0.15 |
| SY6288AAAC | Silergy | 2.5~5.5 | 0.6 | High | SOT-23-5 | 0.1 |
| NCP4545IMN | Onsemi | 0.5~6 | 10 | High | QFN-18 | 1.0 |
And example uscase is shown in the following diagram.
12V or 24V Supply Voltage Management for Main Power Source Switching
| Part # | Manufacturer | Voltage (V) | Current (A) | Active on | Package | Price ($) |
| BTS6163D | Infineon | 5.5~62 | 17 | Low (*1) | TO252-4 | 2.0 |
| BTS4142N | Infineon | 12~42 | 2 | High | SOT-223 | 1.8 |
| BTS452R | Infineon | 6~52 | 1.8 | High | TO-252-4 | 1.2 |
| SIP32429 | Vishay | 6~28 | 3 | High | TDFN-10-EP | 1.0 |
| AOZ1360AIL | Alpha & Ω | 5.5~28 | 6 | High | SOIC-8 | 0.6 |
These ICs can be used for switching between external DC power input and internal battery. Or it can be used for individually turning on/off some partial loads. In the following example, I used AOZ1360AIL for battery path enabling in a UPS configuration.
