LA4550Sample Printed Circuit Pattern Cu foil-reduced board [BTL Use 1] [BTL Use 2] Description of External Parts C1 (C2) : Feedback capacitor. The low cutoff frequency is determined by the following formula. 1 Rf : Feedback resistor fL= 2πC1Rf fL : Low cutoff frequency Since this capacitor as well as decoupling capacitor affects the starting time, the capacitor value must be fixed with the necessary low frequency band fully considered. C3 (C4) : Bootstrap capacitor. The output at low frequencies depends on this capacitor. Decreasing the capacitor value lowers the output at low frequencies. A capacitor value of 47µF or more is required. C5 (C6) : Oscillation blocking capacitor. Use a polyester film capacitor that is good in high frequency response and temperature characteristic. The use of an electrolytic capacitor, ceramic capacitor may cause oscillation to occur at low temperatures. Continued on next page. No.1718–3/9