The FD10C120U is HeroMicro a high-performance 1200V/10A ultrafast recovery diode, designed for medium-power, high-voltage switching power supplies and industrial power electronics. With extremely short reverse recovery time (typ. 40 ns), very low switching losses, soft recovery behavior, and excellent thermal stability, it excels in applications such as PFC (Power Factor Correction), inverters, motor drives, and high-frequency rectification.
1. Key Specifications (from FD10C120U.pdf)
Repetitive Peak Reverse Voltage (VRRM): 1200 V
Average Forward Current (IF(AV)): 10 A (δ=0.5, TC=100°C)
Surge Forward Current (IFSM): 100 A (8.3 ms half-sine wave)
Forward Voltage (VF):
Max 2.94 V @ IF=10A, Tj=25°C
Max 1.96 V @ IF=10A, Tj=150°C (negative tempco enables paralleling)
Reverse Leakage Current (IR):
≤ 60 μA @ Tj=25°C
≤ 250 μA @ Tj=150°C
Reverse Recovery Time (trr):
40–75 ns (Typ. 40 ns, Max 75 ns) @ IF=1A, dI/dt=50 A/μs (standard test condition)
Junction Temperature (Tj): –55°C to +150°C
Storage Temperature (TSTG): –55°C to +150°C
Package: TO-220AC (through-hole, single lead, metal tab)
Thermal Resistance (RθJC): 2.0 °C/W
Test Conditions: All electrical characteristics measured under pulse conditions (300 μs pulse width, duty cycle ≤ 2%) to avoid self-heating.
2. Key Usage Guidelines
(1) Ideal for High-Frequency Hard-Switched Topologies
Ultra-low trr (40 ns) combined with soft recovery minimizes switching-induced di/dt and dv/dt spikes, reducing EMI and protecting paired MOSFETs/IGBTs.
Perfect for PFC boost diodes, inverter freewheeling paths, snubber circuits, and free-wheeling diodes.
(2) Soft Recovery Enhances Reliability
"Soft" recovery produces smooth reverse current waveforms without ringing, suppressing voltage overshoot and reducing stress on main switches, thereby improving system lifetime.
(3) Heatsink Is Required
Power dissipation at 10 A ≈ 25 W (10 A × 2.5 V avg).
Despite the metal tab, RθJC = 2.0 °C/W means junction temperature will exceed 150°C without a heatsink.
Must be mounted on an adequate heatsink with good thermal interface material.
(4) Better Performance at High Temperature
VF decreases from 2.94 V to 1.96 V as Tj rises—reducing conduction loss and enabling natural current sharing in parallel configurations due to negative temperature coefficient.
(5) trr Depends on Test Conditions
The stated trr (40–75 ns) uses IF=1A, dI/dt=50 A/μs—a small-signal JEDEC standard.
In real applications (e.g., IF=10A, dI/dt >100 A/μs), trr and Qrr increase significantly. Use typical curves (Fig. 2–6) for realistic estimation.
(6) Respect Absolute Maximum Ratings
Never exceed 1200 V VRRM, even during transients.
100 A IFSM is for single 8.3 ms pulses only—repeated surges cause permanent damage.
3. Typical Applications
PFC rectifier in 100–300 W AC-DC SMPS
Freewheeling/clamping diode in industrial VFDs and servo drives
DC-link commutation path in solar micro-inverters
Free-wheeling diode in motor controllers
Auxiliary path in high-frequency LLC or phase-shifted full-bridge converters
4. Summary
The FD10C120U delivers outstanding performance with its 1200V/10A rating, 40 ns ultrafast recovery, soft recovery behavior, negative VF tempco, and easy-to-mount TO-220AC package. When implemented with proper heatsinking, derating, and EMI control, it provides a highly efficient and reliable solution for medium-power high-voltage power conversion systems.
