(1) ip-VGs characteristics(转移特性)ID(A)50For gate voltages below athresholdvalue（开启电压）40VGs(tH) MOSFET is off. Beyond30VGs(tH) , the drain current ip20depends on the applied gatevoltage VGs. (VGs↑→ip↑and Ronl)10L? typically Vs(th) is 2 to 4V,_VGS(V)P6240typically gate voltage Vss is 10V.VGsiuth
(1) iD-VGS characteristics （转移特性） For gate voltages below a threshold value （开启电压） VGS(tH) MOSFET is off. Beyond VGS(tH) , the drain current iD depends on the applied gate voltage VGS. (VGS↑→iD↑and Ron↓) • typically VGS(th) is 2 to 4V, typically gate voltage VGS is 10V
（输出特性）(2) ip-Vps characteristicsFig. 2-9(b):iDiDODUGS=7VOn6VUDSG-On5VOoff+1OffUGS4 VUDSosoT0-UDS(a)(b)(c)Figure 2-9 N-channel MOSFET: (a) symbol, (b) i-v characteristics, (c) idealizedcharacteristics
(2) iD-vDS characteristics （输出特性） Fig. 2-9(b):
耗尽型N沟道MOSFET增强型N沟道SLGIPIGSDoDN++++++士N+P型衬底N+0（掺杂浓度低）BOGTBP型衬底SoDTBOSio, isolation level doped in positiveBCGions, conductive channel was builtSwhen ucs = 0uGs ≤UGs(off) ，turn off14
14 耗尽型 N 沟道 MOSFET S G D B Sio2 isolation level doped in positive ions，conductive channel was built when uGS = 0 uGS UGS(off)，turn off S G B P型衬底 (掺杂浓度低) N+ N+ S G D B D 增强型 N 沟道
1.3.3 Characteristics of MOSFET>连续漏极电流ID>浪涌漏极电流IDM>额定耗散功率Pp>最大栅源电压VGs>工作结温T;热阻Rth(i-c)和Rth(j-VA)>击穿电压V(BR)DSS>通态电阻RDS(ON)栅极门槛电压VGs(th7IRF1205
15 1.3.3 Characteristics of MOSFET ➢连续漏极电流ID ➢浪涌漏极电流IDM ➢额定耗散功率PD ➢最大栅源电压VGS ➢工作结温Tj ➢热阻Rth(j-c) 和Rth(jA) ➢击穿电压V(BR)DSS ➢通态电阻RDS(ON) ➢栅极门槛电压VGS(th)
1.3.4 A simple MOSFET eguivalentcircuitInputcapacitance·Input CapacitanceCas: large,essentiallyconstantGD· Output Capacitance Cgd : small, highlynonlinear·ReverseTransferCapacitance（反向转移电容）CissCds:intermediatein value, highlynonlinearSswitchingtimesdeterminedbyrateatwhichgatedriver charges/discharges Cgs and CgdCiss=Cgs+ CgdMOSFET internal capacitancesOutputcapacitanceCgdGDGO DCCgs市+CdsCossS0SCoss=Cgd+Cds
1.3.4 A simple MOSFET equivalentcircuit •Input Capacitance Cgs : large, essentially constant • Output Capacitance Cgd : small, highlynonlinear • ReverseTransfer Capacitance（反向转移电容） Cds : intermediate in value, highlynonlinear •switching times determined by rate at which gate driver charges/discharges Cgs andCgd