The MSN4688B is HeroMicro a dual-channel MOSFET integrating both N-channel and P-channel transistors in a single SOP-8D package. Utilizing advanced trench technology, it offers ultra-low on-resistance (RDS(on)) and low gate charge (Qg), making it ideal for power management, switching control, and load driving applications. Its compact footprint and excellent thermal performance make it a preferred choice for high-efficiency circuit designs.
1. Device Overview
N-Channel Specifications:
Drain-Source Voltage (VDS): 40 V
Continuous Drain Current (ID): 8 A (TA=25°C)
On-Resistance (RDS(on)): < 22 mΩ (@ VGS = 10 V)
Typical Gate Charge (Qg): 12 nC (@ VGS = 8 V)
P-Channel Specifications:
Drain-Source Voltage (VDS): -40 V
Continuous Drain Current (ID): -7.2 A (TA=25°C)
On-Resistance (RDS(on)): < 40 mΩ (@ VGS = -10 V)
Typical Gate Charge (Qg): 8 nC (@ VGS = -4.5 V)
Package: SOP-8D, RoHS compliant, surface-mountable.
2. Key Usage Guidelines
(1) Gate Drive Design
N-Channel: Use VGS = 10 V or 4.5 V for full enhancement. RDS(on) is typically 17 mΩ at 10 V.
P-Channel: Apply negative gate-source voltage (e.g., VGS = -10 V) for low RDS(on)). It remains low even at -4.5 V.
Gate Resistance (RGEN): A 25 Ω resistor is recommended to shape the switching waveform and suppress ringing.
(2) Thermal Management
Maximum Power Dissipation (PD): 2.5 W (TA=25°C)
Thermal Resistance (RθJA): 62.5 °C/W
Use adequate copper area on the PCB as a thermal pad to improve heat dissipation. Derate current under high ambient temperatures.
(3) Switching Performance
Switching Times (P-Channel, VGS = -4.5 V):
Rise Time (tr): 12 ns (typical)
Turn-Off Delay Time (td(off)): 46 ns (typical)
Fall Time (tf): 6 ns (typical)
Low Qg and fast switching make it suitable for high-frequency applications such as DC-DC converters and motor drivers.
(4) Safe Operating Area (SOA)
Refer to Fig.6 (Maximum Safe Operation Area) in the datasheet to ensure operation remains within thermal limits.
Avoid high voltage and high current simultaneously to prevent thermal runaway.
(5) Body Diode Characteristics
The P-channel body diode supports robust freewheeling:
Continuous Current (IS): -7.2 A
Pulsed Current (ISM): -28.8 A
Forward Voltage (VSD): -1 V (@ IS = -1 A)
Ideal for inductive loads (e.g., motors, relays), eliminating the need for external flyback diodes.
(6) Electrostatic Discharge (ESD) Protection
MOSFETs are ESD-sensitive. Use ESD-safe practices during handling and assembly.
3. Typical Applications
H-bridge motor drivers
Power switches and load switching
Synchronous rectifiers
Battery management systems
DC-DC buck/boost converters
4. Summary
The MSN4688B delivers high integration and efficiency with its dual N+P channel design, low RDS(on), and low gate charge. By properly designing the gate drive, optimizing thermal layout, and adhering to SOA limits, engineers can fully leverage its performance for reliable and efficient power system designs.
