My project is a 1kW high efficiency, 12 V DC to 230 V AC converter.
My present question only concerns the 1st stage which is a step-up stage with following characteristics :
- transformer used in push-pull topology
- 10 V DC < Vin < 18 V DC
- I in max = 110 A
- Vout = 350 V DC
- I out max = 3.2 A
- frequ. = 100 kHz
- High efficiency
- not overpriced
I would like to find the right PWM controller but there's a lot of part nums ! Here are the ones which satisfy my Vin and frequency constraints :
- UC1856, UC2856, UC3856
- UC1823A, UC2823A, UC2823B, UC3823A, UC3823B,
- UC1825A, UC2825A, UC2825B, UC3825A, UC3825B
- UC186* UC286* UC386* ( *= 1 to 8 )
- SG2524, SG3524
- UC1846, UC1847, UC2846, UC2847, UC3846, UC3847
- UC1526, UC2526, UC3526
- UC1525A, UC1527A, UC2525A, UC2527A, UC3525A, UC3527A
- UC1524, UC2524, UC3524
- UC2827-1, UC2827-2, UC3827-1, UC3827-2
The controller must tune the ratio according to Vout and primary current.
For current sensing, I still don't know if I will use a resistive shunt or a hall effect sensor. I'm open to suggestions.
To switch primary coils, I think to use 2 parallels MOS FET IRFP7430 (Qg=300nC , Rdson=1mOhm) on each branch (also open to suggestions).
If I use a 2A gate driver, it gives me a 0.6µs theorical opening/closing time. Any idea if it is enough (considering the 10µs period) ?
If it is good, I can choose a PWM controller with 2A drivers, if not, I can choose small ones and add external drivers.
Also perhaps 1st prototype will use standard diode rectifier, but for future efficiency improvements, I would prefer to use mosfet rectifier ready components (i.e. a pwm controller with sync output pin).
So, the main questions are : Which PWM controller do you recommend ? And is there useful surrounding components ?
Any advice is welcome.