BUY SLA4061 https://www.utsource.net/itm/p/11543700.html

Manufacturer: Sanken Description: SLA4061 is a NPN Darlington power transistor with high voltage and high current capabilities. Features: High voltage: VCEO = 800V High current: IC = 4A Low saturation voltage: VCE(sat) = 1.2V (Typ.) High gain: hFE = 1000 (Typ.) High power dissipation: PD = 25W (Tc = 25°C) High frequency operation: fT = 10MHz (Typ.) High reliability: MTTF = 5,000,000 hours (Typ.) Low noise: NF = 0.5dB (Typ.) Low thermal resistance: Rth(j-c) = 0.6°C/W (Typ.) RoHS compliant Applications: Switching power supplies DC-DC converters Motor drivers High voltage amplifiers Automotive applications (For reference only)