• DCM+QR Combined Operating Mode
• Adaptive OCP (LPS, Limited Power Source) 
• Direct E-mode GaN FET Driver 
• Programmable Gate Driver Current
• 140V LDO in VCCH pin
• Switching Frequency Range: 25kHz~500kHz
• Valley Lockout from 1 to 6th
• Low Frequency Burst (1kHz)
• Frequency Modulation to Reduce EMI Noise
• Internal Soft Start  Integrated 700V HV Start up
• Brown In/Out Protection 
• X-cap Discharge Protection
• Programmable Output OVP&UVP
• Current Sense Resistor Short Protection 
• Internal & External OTP 
• Compact Package: SSOP9

SY22812 is a high frequency QR Flyback controller targeting at PD adaptors and fast charges. SY22812 can drive enhancement GaN FET directly. It is suitable for wide output voltage range application, with maximum 240W output power. Maximum switching frequency can be up to 500kHz, so size of transformer and capacitors can be reduced.

In normal QR Flyback solutions, valley number always jumps between 1-2 or 3-5, which will increase Vo ripple and bring audio niose. SY22812 can lock valley with proprietary circuit and valley number can be 1 to 6th. System state is more stable than normal QR solutions.

SY22812 works under peak current mode. It adopts QR mode and GaN FET can be turned on at valley point to reduce switching loss, especially under high input voltage. If load decreases more, SY22812 will enter DCM to reduce switching frequency for higher efficiency. If load is very light, SY22812 will enter burst mode to reduce power loss.

SY22812 also provides comprehensive and reliable functions including HV startup, X-cap discharge, brown out protection, output OVP and UVP, OLP, VCC OVP, internal and external OTP, etc.

SY23434 is recommended to be used as secondary side SR controller in conjunction with SY22812. Then ZVS operation can be achieved for higher efficiency.

SY22812 is available with SSOP9.