llc converter (full bride, synchronous fets)
description
the llc converter is a resonant converter that can achieve zvs operation (primary side switch) and zcs operation (secondary side switch) simultaneously. it achieves low noise and high efficiency by generating a sinusoidal current waveform with the switch network and resonant circuit.
this circuit consists of a full-bridge switch circuit on the primary side and a center-tap transformer on the secondary side using fets instead of diodes. this type of configuration is commonly used for relatively high power (around several kw).
overview
- same semiconductor devices
- series resonance between cr and lr
- lr is sometimes implemented as the leakage inductance of the transformer
- voltage control is done through frequency high complexity design
- soft switching is defined by magnetizing inductance lm, not function of the load.
- efficiency around 98% suits titanium!
- frequency 100..200 khz
circuit
key products
| product category | product family | product number | feature |
|---|---|---|---|
| primary side (hv) | 600v sj mos | prestomos (jnx series) | excellent switching behaviour (low qrr, short trr) |
| secondary side (lv) | 100v mosfet | rq3p300bh | 100v mosfet in small hsmt8 package |
| 40v mosfet | rs1g300gn | 40v mosfet in hsop8 package | |
| gate driver | hv side | bm60212fv-c | dual driver, ideal for half- and full-bridge topologies. |
| lv side | bd85506f | synchronous rectification controller ic |
simulation
coming soon
related topologies
llc converter (full bridge, diode rectification)
