各个厂商的加密手段不同，主要分为几类：一级加密（可擦除）；二级加密（加密）；三级加密（加“死密”）。不同的芯片可能提供了一种或多种级别的加密方式，根据不同的需求灵活使用加密方案才可以做到游刃有余。一级加密如果你的产品可能需要升级固件，建议使用这种加密方式。一级加密又分为多种形式，*常见的一种形式经常在芯片手册中叫做“Protect”。加密后如果试图读出芯片中的代码，则会读出全000，或者是全0FF，甚至是随机数据，但是通过某些特殊的方法，比如擦除或是解保护，就可以将芯片重置为默认状态。
PV063R1K1T1NFR1
PV063R1K1T1NFHS
PV063R1K1T1NMM1
PV063R1K1T1NMRC
PV063R1K1T1NFWS
PV063R1K1T1NFRC
PV063R1K1T1NFF1
PV080L1K1T1NFFC
PV080R1K1B1NSLB
PV080L1K1T1NFHS
PV080R1L1T1MULC
PV080R1K1A1NFWS
PV080R1K1T1NFRL
PV080R1K1T1NGLA
PV080R1K1T1NMMC
PV080R1L8L3NULC
PV080R1L8T1NULC
PV092R1K8T1N001
PV092R1K1T1NFRZ
PV092R1K1T1NMM1
PV092R1K1T1NMRK
PV092R1K4T1NFHS
PV092R1K1T1NKLC
PV092R1K1T1VMMC
PV092R1L1T1WTCC
PV092R1K1T1NF
PV092R1D1T1NMMC
PV092R1K1T1NGLC
PV092R1K1T1NMF1
PV092R1K1T1WFR1
PV092R1K1T1NULZ
PV092R1K1T1NHLC
PV092R1K1T1NFFC
PV092R1K1A1NFWS
PV092R1K1T1NFHS
PV092R1K1T1NFF1
PV092R1K1T1NFWS
PV092R9K1T1NMMC
PV092R1K1T1NFR1
PV092R9K1T1NFWS
PV092R1K1T1N001
PV092R1K1T1EMMC
PV092R1K1S1NFWS
PV092R1K4T1NMR1
PV092R1L1L3WTCC
PV092R1K1T1NUPM
PV092R1K8T1NMMC
PV092R1K1T1VFDS
PV092R1K1T1NMRC
PV092R1K1T1WMM1
PV092R1K1T1PFDS
PV092R1K1T1WMRC
PV092R1K1A1NMMC
PV092R1K1T1NMMC
PV092R1K8T1VMMC
PV092R1K1T1NMMK
PV092L1K1T1NFWS
PV092R1K1T1NFDS
PV092R1K1T1NKLA
PV092L1K1T1NMMC
PV092R1K4T1NFR1
PV092R1K1T1NMFC
PV092R1K1T1N100
PV092R1K8T1NFWS
PV092R1K1JHNMMC
PV092R1K4T1NMMC
PV092R1K1A4WFRZ
PV092R1K1AYNMRZ
PV092R1K1T1WFDS
PV092R1K1T1NFRC
PV092R1K1T1NHCC
PV092R1D1T1VMMC
PV092R1K1T1NMRZ
PV092R1K1T1WMR1
PV092R1K1T1WMMC
PV092R1K1T1NMR1
PV092R1L1T1NMMC
PV092R1K1T1NFFP
PV092L1K1T1N001
PV092R1D1T1NGLC
PV092R1K1T1NMLA
PV092R1K4T1NFPD
PV092R1L1T1NFPD
PV092L1K1J1NFR1
PV092R1K1A1NSLA
PV140R1K1T1NFRL
PV140L1K8T1NSLC
PV140R1K1T1NTCB
PV140R1L1A1NF
PV140L9G3B1NTCC
PV140R1K1T1NWLA
PV140R1K1T1NSCA
PV140R1D3T1VFHS
PV140L1G1T1NFFP
PV140L1K1T1NFFC
PV140L1K1T1NFFP
PV140L1K1T1NFWS
PV140L1L1T1NWCC
PV140R1D1T1NFFC
PV140R1F1T1NFHS
PV140R1F1T1NYCC
PV140R1F3T1NFFC
PV140R1F3T1NFRP
PV140R1G1T1VFFC
PV140R1K1A1NSCC
PV140R1K1B1NFWS
PV140R1K1B1NUPG
PV140R1K1T1NFDS
PV140R1K1T1NFFC
PV140R1K1T1NFFD
PV140R1K1T1NFFP
PV140R1K1T1NFF1
PV140R1K1T1NFHS
PV140R1K1T1NF
PV140R1K1T1NFRC
PV140R1K1T1NFRD
PV140R1L1T1NUPG
PV140R1L1T1NWCC
PV140R1L4T1NUPG
PV140R1K1T1NMMC
PV140R1K1T1NMRK
PV140R1K1T1NMRZ
PV140R1K1T1NULC
PV140R1K1T1NWCC
PV140R1K1T1NWLC
PV140R1K1T1WMMC
PV140R1L1T1NMMC
PV140R9K1T1NUPZ
PV140R9L1LKNWCC
PV140R9K1A1NSLCK0173
PV140R9K1T1NFDSK0186
PV140R9K1T1NFFCK0011
PV140R9K1T1NFHSK0017
PV140R9K1T1NFRCK0107
PV140R9K1T1NFWSK0032
PV140R9K1T1NFWSK0155
PV140R9K1T1NKCCK0175
PV140R9K1T1NMLCK0081
PV140R9K1T1NSLCK0003
PV140R9K1T1WSCCK0072
PV140R9K4T1NFFPK0088
PV140R9K4T1NZCBK0154
PV140R9K4T1WFRPX5918
PV140L9G1T1NFFPK0083
带宽的不同对测试结果而言到底有什么样的影响呢？下面我们看一个实际测试案例，在某LED测试现场，用两台带宽不同的功率计测试LED驱动的输入（市电工频50Hz）电参数，包括电压、电流、功率、功率因数等，测试结果如下图所示：从图中可以看到，两台设备测试的电压、有功功率基本一致，但是功率因素确相差很大。而功率因数的计算跟无功功率有非常密切的关系，因此可以判断两台设备测试的无功功率肯定有相差。两台设备的标称的基本精度都一样，但带宽却相差很大。
