Part Number: UCC28740 Hello,
This post is a follow-up to my previous thread:
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1650390/ucc28740-ucc28740-vdd-is-cycling-hiccup-mode-but-drv-is-not-switching…
Part Number: UCC28740 Other Parts Discussed in Thread: TIDA-00701 Hello TI Support Team,
I am currently reviewing the UCC28740 flyback controller for an isolated power supply design and would like to clarify a few points related to protection behavior…
Part Number: UCC28740
Dear
Problem description:U1 VDD is cycling from 7.6V to 21V, o/p cannot be stable, the peak of o/p is only 21V, cannot reach to 24Vdc.Thus 431,817 and FB cannot work. Vcs waveform is for reference.
Input: 90~132Vac
o/p: 24V…
Part Number: UCC28740 Hello, I am following TI's slides "UCC28740 Feedback Loop & Compensation Design" When Cz and Cp are = 0, I get that midband gain |G| = -34.90V/V, or 30.86dB. Crossover frequency is 360Hz. Dominant pole from Cout and RL/2 is 10.3Hz…
Part Number: UCC28740
Hello Jinesh,
I am currently working on an isolated flyback SMPS design and I am experiencing an issue with improper PWM generation from the controller. I would appreciate your guidance in resolving this problem.
Design Overview…
Part Number: UCC28740
Hello Jinesh,
I am currently working on an isolated flyback SMPS design and I am experiencing an issue with improper PWM generation from the controller. I would appreciate your guidance in resolving this problem.
Design Overview…
Part Number: UCC28740 From slides "UCC28740 Feedback Loop & Compensation Analysis", it is stated that ZL(s) = [(RL/2) * (1/(1+sCout+RL/2)]
It was noted that 1/2 factor is due to differentiation.
I was expecting to see a simple Rout||sCout equation…
Part Number: UCC28740 Other Parts Discussed in Thread: PMP10936 We are working on a PSU design using TI’s UCC28740DR PWM controller, following “TI - PMP10936” reference design, and using “sluc487b” spreadsheet.
Currently we are facing some issues, regarding…
Part Number: UCC28740 Hello, How is the Rcs equation derived, given in datasheets: Rcs = Vccr*Nps*sqrt(efficiency)/(2Iocc)
My understanding: Rcs = Vcst/Ipk Ipk = 2Pout/(Vin_min*Dmax*efficiency)
So Rcs = Vcst*Vin_min*Dmax*efficiency/2Pout
Questions…
Part Number: UCC28740 Other Parts Discussed in Thread: TL431 , Hello,
I am troubleshooting a new prototype based on the UCC28740DR controller, and I am facing a startup issue. The controller seems to be in a continuous hiccup mode, and the output voltage…
