The AO4828 is HeroMicro a high-performance dual N-channel power MOSFET fabricated using advanced trench technology, integrating two identical N-channel transistors into a compact SOP-8 package. With 60V blocking voltage, 4.5A continuous current, ultra-low on-resistance (typ. 30 mΩ @ VGS=10V), and low gate charge, it is engineered for high-efficiency, high-density power management and load-switching applications such as DC-DC converters, motor drives, battery protection, USB power switches, and portable electronics.
1. Key Specifications (from AO4828.pdf)
Drain-Source Voltage (VDS): 60 V
Continuous Drain Current (ID): 4.5 A (TA=25°C), 3.5 A (TA=70°C)
Pulsed Drain Current (IDM): 18 A (pulse width ≤300 μs, duty cycle ≤2%)
On-Resistance (RDS(ON)):
Typ. 30 mΩ (Max 36 mΩ) @ VGS=10V, ID=4A
Typ. 34 mΩ (Max 45 mΩ) @ VGS=4.5V, ID=3A
Gate Threshold Voltage (VGS(th)): 1–2.5 V (@ ID=250 μA)
Total Gate Charge (Qg): 19 nC (@ VGS=10V, VDS=48V, ID=4A)
Input Capacitance (Ciss): 1020 pF (@ VDS=15V, f=1MHz)
Switching Speed (VDD=30V, ID=4A, RG=3.3Ω):
td(on): 3 ns, tr: 34 ns
td(off): 23 ns, tf: 6 ns
Body Diode:
VSD ≤ 1.2 V @ IS=1A
trr: 12.1 ns, Qrr: 6.7 nC
Single-Pulse Avalanche Energy (EAS): 22 mJ
Package: SOP-8 (surface-mount with exposed pad)
Power Dissipation (PD): 1.5 W (limited by 150°C junction temperature)
Thermal Resistance: RθJA = 85 °C/W (on 1 in², 2 oz Cu PCB)
Operating Junction Temperature: –55°C to +150°C
Environmental: Green (lead-free) option available
2. Key Usage Guidelines
(1) Dual-Channel Integration Saves Space & Cost
Two independent N-MOSFETs in SOP-8 enable half-bridge, synchronous rectification, dual load switches, or redundant power paths, reducing PCB area and BOM cost.
(2) Logic-Level Compatible—Easy to Drive
RDS(ON) < 45 mΩ at VGS = 4.5 V allows direct drive from 3.3V/5V logic or MCU GPIOs (use a gate driver or totem-pole buffer for faster switching).
(3) SOP-8 Thermal Limitation Is Critical
PD = 1.5 W assumes 1 in², 2 oz Cu PCB. Without enhanced thermal design, continuous current must be derated significantly above 50°C ambient.
Solder the exposed pad to a large copper pour with multiple thermal vias to inner ground planes—failure to do so will cause thermal runaway.
(4) High-Speed Switching for High-Frequency Use
Total switching time ~40 ns and Qg = 19 nC support operation above 500 kHz (e.g., synchronous buck).
While tested with RG = 3.3 Ω, increasing RG to 10 Ω can reduce EMI and voltage overshoot in real designs.
(5) Fast Body Diode Suitable for Synchronous Rectification
trr = 12.1 ns and Qrr = 6.7 nC make the body diode acceptable for freewheeling in low-power synchronous converters, though IS is limited to 4.5 A.
(6) Limited Avalanche Energy—Use Caution with Inductive Loads
EAS = 22 mJ provides basic UIS capability, but external flyback diodes or clamping circuits are recommended when switching relays or motors.
3. Typical Applications
Dual USB power switches in portable devices
High/low-side MOSFETs in synchronous buck converters (verify current rating)
Battery pack charge/discharge protection (dual-cell or multi-cell)
Small motor H-bridge drivers (one AO4828 per half-bridge)
Dual-channel load switches in industrial I/O modules
4. Summary
The AO4828 excels with its dual-channel integration, 60V/4.5A rating, 30 mΩ low RDS(ON), logic-level compatibility, and compact SOP-8 package. However, its 1.5 W power dissipation limit demands meticulous PCB thermal design. With proper layout, driving, and derating, it delivers reliable, efficient performance in space-constrained power systems.
