TL3844BDR-8 Oscillator Frequency?

[Kronkulus]

Hey all!

I'm trying to design a flyback converter with the TL3844BDR-8. I'm in the middle of going through all the design equations, and I've come across something that is just confusing the bajeezus out of me.

I'm not sure if I'm allowed to post figures from datasheets, so I'll just describe what I'm seeing to the best of my ability. I chose a maximum duty cycle of 45% for the design, and a graph in the datasheet shows that Rt must be greater than 3.5k to meet this requirement. Alright that's fine. Then TI gives an equation for oscillator frequency:

f = 1/(Rt*Ct) if Rt < 5k
f = 1.72/(Rt*Ct) if Rt >5k

Directly below these equations is a graph with multiple lines, Y axis is Rt, X axis is frequency. Each line is showing how the oscillator frequency changes with the timing resistor for multiple different timing cap values. According to this graph, an Rt of 4k with a Ct of 4.7nF should give me close to 100kHz. Plug those into the equation above and you get about 53kHz. Am I going nuts, or is there something I'm not understanding about what these graphs/equations are telling me?

[Kronkulus]

I may have found my answer, all I had to do was post in the forum, works every time!

I think the graphs are showing the Rt>5k line, but they continued them down below 5k for some reason. As Dave would say, TRAP FOR YOUNG PLAYERS.