掌握视频信号的箝位、偏置和交流耦合

(DAC)DAC()DCSCART(SCARTPeritel)DC“”(RC)S(C)(Y)(Cvbs)RGB“”(PbPr)RGB“”()“DC”(ADC)()DC111.RC2(EIA770-123)SPbPr(Y)RGB0V(“”“”)+700mV2NTSCPALRGBPC()RGBDAC0V2.RGB(a)(b)S(c)(d)DC——DC(PAL/DVB[SCART]EN50049-1NTSCSMPTE256MDC)“”1“”RCRC-3dB610S2MHz750.1µFY()Cvbs()RGB(2530Hz)75-3dB35Hz1000µF()1%2%3aRCRCRSRIRIRF([CMRR])-3dB1/(21RSC)(PSRR)CMRRRC3b3aR1=R2VCCVCCVEE3bVCC3aR1=R23bPSRR-6dBPSRR(3c)(RX)RfRiRxC1C2Ri35Hz(C3)RXC13d3PSRRDCRXRfRiC3(Zout)3cC1C2RiC1CMRR3.RC(a)(b)(c)PSRR(d)()——RGB(0V)(-300mV)(+700mV)1(APL)4a(CR)(-300mV)(0V)“”(MAX4399MAX4098MAX4090)——FET(4b)(4c)“”(Vref)PbPr±1(LSB)±2.75mV±1LSB4dU2(U1)(Vref)U1Vref(C)-(S/H)4.a)b)c)d)RxCxU2RC16ms(NTSC/PAL)RC200nsU2/(MAX4124/25)U1S/HChold()5.S/H——Vref——DACVref()——S/H