SNVSAH5A September 2017 – May 2020 LM73605 , LM73606
PRODUCTION DATA.
The LM73605 and LM73606are internally compensated. Typically, select RFBT ≤ 100 kΩ, then CFF is not needed. When very low quiescent current is needed, RFBT = 1 MΩ can be used. If COUT is mainly ceramic type low ESR capacitors, an external feedforward capacitor, CFF, can be needed to improve the phase margin. Add CFF in parallel with RFBT. CFF is chosen such that the phase boost is maximized at the estimated crossover frequency fX. Equation 21 was tested.
With this design, because RFBT = 100 kΩ is selected, no CFF is needed.