**Detailed parameter description:**
- **Model:** APM2321AC-VB
- **Silkscreen:** VB2290
- **Brand:** VBsemi
- **Package:** SOT23
- **Channel type:** P-Channel
- **Maximum drain-source voltage:** -20V
- **Maximum drain current:** -4A
- **Drain resistance:** RDS(ON) = 57mΩ @ VGS=4.5V, VGS=12V
- **Threshold voltage:** Vth = -0.81V

**Application introduction:**
APM2321AC-VB is a VBsemi brand P-Channel field effect transistor in SOT23 package. This product is suitable for circuit design that requires high-performance P-Channel transistors, with low drain resistance and high performance.

**Application Examples:**
1. **Power Management Module:** Due to its P-Channel nature and low drain resistance, APM2321AC-VB can be used in power switching and regulation circuits to improve the efficiency of power modules.
2. **Motor Drive Module:** In areas where efficient energy conversion and motor control are required, APM2321AC-VB can be used as a key component in motor drive modules.
3. **Battery Protection:** Suitable for battery protection circuits to ensure the safety and stability of batteries during charging and discharging.

Overall, APM2321AC-VB plays a key role in circuit designs that require P-Channel field effect transistors, especially in power management, motor drive, and battery protection.