DC2490A

DC2490A is a demonstration circuit featuring the LT®8303. This LT8303 is a micropower no-opto isolated flyback converter. This demo circuit outputs 5V, and maintains tight regulation with a load current from 2.5mA to 0.84A over an input voltage from 36V to 72V. The output current capability increases with the input voltage. The DC2490A needs less than 0.5% of its full output power as a minimum load to maintain good output voltage regulation. On the DC2490A, in order to avoid preloading, a 5.6V Zener diode is placed between its VOUT+ and VOUT- to serve as a minimum load. The demo circuit can be easily modified for different applications with some predesigned transformers. The LT8303 is a micropower high voltage isolated flyback converter. By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no third winding or opto-isolator for regulation.

• 0.65A at VIN = 36V, 0.73A at VIN = 48V, 0.84A at VIN = 72V at maximum output current
• 50mV output voltage ripple (peak to peak) at VIN = 48V, IOUT = 0.73A
• 260KHz typical switching frequency at VIN = 48V, IOUT = 0.73A
• 86% efficiency at VIN = 36V, IOUT = 0.65A