A feedforward capacitor, C_FF on the order of tens of picofarads, is used to improve phase margin and transient response of circuits which have output capacitors with low ESR. Since this C_FF capacitor can conduct noise from the output of the circuit directly to the FB node of the IC, a 4.99-kΩ resistor, R_FF, must be placed in series with C_FF. If the ESR zero of the output capacitor is below 200 kHz, no C_FF must be used.

If output voltage is less than 2.5 V, C_FF has little effect, so it can be omitted. If output voltage is greater than 14 V, C_FF must be used cautiously since it can easily introduce too much gain at higher frequencies.

If 1 MΩ is selected for R_FBT, then a feedforward capacitor C_FF must be used.