Hello, TI expert.
I want to know whitch parameter is more dominant, RTON or RBOT & RTOP ?
1 Does the output voltage change when the value of the resistor RTON attached to the TON pin changes?
→ When Vout is 1.25, RTON = 21.75kΩ, but if RTON deviates ±1% due to variations in resistance, will Vout also deviate?
Or does something like the TON pin resistance value discriminator have resolution, and does the output voltage remain the same even with some deviation?
If so, what percentage of resistance variation is acceptable for the resolution of the resistance value discriminator?
2 I think that the output voltage is also determined by the On time, but looking at the specifications, it seems that it is determined only by the resistor attached to FB.
→ I think that what is determined by RTOP and RBOT attached to FB is not the output voltage value, but the variable range of the output voltage.
I think that the voltage that is actually output is determined by the On time (value of RTON).
The job of RTOP and RBOT is to divide Vout to make VFB=VREF±10%, right?
Assuming that R9: 1.4kΩ, R7: 1kΩ, and VREF=0.508V, DCDC will stop when Vout is outside 1.10 to 1.34V.
In other words, it is RTON that determines the actual output voltage, and I think that R7(RBOT) and R9(RTOP) only determine the error range of the output voltage, am I wrong?
I have attached cutouts and tables of the specifications in the attached EXCEL, so please take a look if you like.
By the way,
3 If the voltage to the EN pin is supplied by an external supply rather than a voltage divider of Vin, do I need a pull-down resistor?
Best regards.