Hello team,
i have some doubts and want some clarification regarding TEA1733T ic.
tea1733t ic datasheet:
https://www.nxp.com/docs/en/data-sheet/TEA1733T.pdf
Application notes:
https://www.nxp.com/docs/en/application-note/AN10868.pdf
Fig:1 -This is the reference schematic diagram of TEA1733T IC.
1- My first question is if i want 24v 3 amp as an outpt then what is the value of these resistor R23 and R24 (how these resistors are to be selected),what about R25 and C17?
2- My second question is what is the switching voltage of the MOSFET that fed to the transformer primary side where gate voltage is 10-12V and switching frequency is 66khz?
Thank you.
Hello Justin,
For a 24V/3A output, the feedback divider (R23 and R24) sets the TL431 reference at 2.5V. The ratio is:
So if R24 = 5.1 kΩ, R23 ≈ 43 kΩ.
R25 and C17 form part of the compensation network for loop stability. Typical values are R25 = 1 kΩ–10 kΩ and C17 = 100 nF–470 nF, tuned per AN10868.
The MOSFET switches the rectified DC bus voltage, which is about 160 V for 115 VAC input or 325 V for 230 VAC input. Gate drive is 10–12 V and the switching frequency is around 66 kHz.
BRs, Tomas
