電子書-RTL Design Style Guide for Verilog HDL540頁A FF having a fixed input value is generated from the description in the upper portion of
Example 2-21. In this case, ’0’ is output when the reset signal is asynchronously input,
and ’1’ is output when the START signal rises. Therefore, the FF data input is fixed at
the power supply, since the typical value ’1’ is output following the rise of the START
signal.
When FF input values are fixed, the fixed inputs become untestable and the fault detection rate drops. When implementing a scan design and converting to a scan FF, the scan
may not be executed properl not be executed properly, so such descriptions , so such descriptions are not are not recommended. recommended.[1] As in the lower
part of Example 2-21, be sure to construct a synchronous type of circuit and ensure that
the clock signal is input to the clock pin of the FF.
Other than the sample shown in Example 2-21, there are situations where for certain
control signals, those that had been switched due to the conditions of an external input
will no longer need to be switched, leaving only a FF. If logic exists in a lower level and a
fixed value is input from an upper level, the input value of the FF may also end up being
fixed as the result of optimization with logic synthesis tools. In a situation like this, while
perhaps difficult to completely eliminate, the problem should be avoided as much as possible.
標簽：
RTL
verilog hdl
上傳時間：
2022-03-21
上傳用戶：canderile
le flows through MOS channel while Ih flows across PNP transistor Ih= a/(1-a) le, IE-le+lh=1/(1-a)' le Since IGBT has a long base PNP, a is mainly determined by ar si0 2ar= 1/cosh(1/La), La: ambipolar diff length a-0.5 (typical value)p MOSFET channel current (saturation), le=U"Cox"W(2"Lch)"(Vc-Vth)le Thus, saturated collector current Ic, sat=1/(1-a)"le=-1/(1-a)"UCox"W/(2Lch)"(Vo-Vth)2Also, transconductance gm, gm= 1/(1-a)"u' Cox W/Lch*(Vo-Vth)Turn-On1. Inversion layer is formed when Vge>Vth2. Apply positive collector bias, +Vce3. Electrons flow from N+ emitter to N-drift layer providing the base current for the PNP transistor4. Since J1 is forward blased, hole carriers are injected from the collector (acts as an emitter).5. Injected hole carriers exceed the doping level of N-drift region (conductivity modulation). Turn-Off1. Remove gate bias (discharge gate)2. Cut off electron current (base current, le, of pnp transistor)
標簽：
igbt
上傳時間：
2022-06-20
上傳用戶：wangshoupeng199
