I'm designing a circuit that needs a 2 kHz square wave, which will be generated by a 555 timer.

Looking at the reference circuit schematic...:

[![555 astable timer schematic](https://i.stack.imgur.com/cH1e0.png)](https://i.stack.imgur.com/cH1e0.png)

I've worked out compatible values for R\_A, R\_B, and C that will work via an online calculator. My goal is to have as close to a 50/50 duty cycle as possible. In the limit, if R\_A = 0R, then both charging and discharging are through R\_B only and it's 50/50. This would suggest R\_A = 0R, R\_B = 3k52 (i.e., a 3k3 and 220R in series), C = 100nF.

Is there a limit to how low R\_A can be? Can I use R\_A = 100R? 1R? Eliminate it and short DISCH to Vcc with a jumper? (Would this fry the circuit? Or be very power-wasteful? Or..?)

As a second related question, I can't find guidance in the datasheet for a good value for R\_L. If OUT is a push-pull output from the internal op-amp, why is R\_L necessary? Should I just add a 1k0 (I assume, to improve the OUT rise time?) and call it a day, or is there a relevant equation here? If it matters, Vcc = 6V as I'll be using 4x AA batteries to power the circuit.