The elements are comparable, however rated at 5 to 100V or 5 to 80Vin, and a couple of.5A or 3.5A out.
There will not be synchronous rectifier ICs. As an alternative they embody a 500mΩ (950mΩ max) collection swap and anticipate a excessive present Schottky diode to be related externally.
Half numbers are AP68255Q (8V 2.5A), AP68355Q (80V 3.5A), AP6A255Q (100V 2.5A or AP6A355Q (100V 3.5A).
Management is thru a relentless on-time scheme, with the collection swap turned on each time the output drops under its regulation threshold.
“This system leads to quick load/line transient response, simple loop stabilisation, and low output voltage ripple, making the units simpler to include by requiring fewer exterior elements,” claimed Diodes. “On-pulse timing is calculated, inversely proportional to enter voltage and immediately proportional to output voltage, to keep up a pseudo-fixed frequency over the enter voltage vary” – at ~300kHz. Minimal off-time is usually 200ns.”
Fixed frequency operation eases EMI filtering as does, it claims, the corporate’s proprietary gate-driver which is meant to “scale back swap node ringing results with out sacrificing the turn-on and turn-off occasions of the n-channel mosfet swap”.
Though that is an asynchronous buck, there may be an inner 10Ω mosfet within the synchronous rectifier place (labelled Q2 in diagram left).
What’s that for?
“Q2 is a small low-side FET to assist refresh the bootstrap capacitor voltage within the occasion of lengthy interval no switching,” the corporate instructed Electronics Weekly. “This often will occur in PFM [pulse-frequency modulation] and no load conditions.”
Different options embody an allow pin which may shut the machine down to five.6μA in addition to programme the under-voltage lock0out threshold if two resistors are related to it.
Over-current safety has frequency fold-back to cut back junction temperature throughout faults, and is backed by over-temperature safety with hysteresis between 160 and 140°C. Nominal working vary is -40 to +125°C.
Qualification is to AEC-Q100 Grade 1, manufacturinng services are IATF 16949 licensed and there are supporting PPAP paperwork.
For non-automotive use there are associated industrial-grade elements.
For example, discover the 100V 3.5A AP6A355Q on this Diodes internet web page.
At a lot increased powers, Vicor launched 48 to 12V automotive DC-DC converters in March
