Philips Semiconductors Product Specification Rev. 3.1 August 2004
I•CODE Reader IC SL RC400
88
13.3 Changing the Modulation Index
The following table shows the modulation index, if a 50 ohm antenna is used and GsCfgCW is set to 0x3F.
To change the modulation index the GsCfgMod register has to be changed similar as the GsCfgCW register.
GsCfgMod rel. resistance Mod. index GsCfgMod rel. resistance Mod. index
Rrel(during modulation)
Rant=50Ω Rrel(during modulation)
Rant=50Ω
0x00 Infite 0x18 0,065 4,15%
0x10 Infite 0x19 0,058 3,63%
0x20 Infite 0x25 0,054 3,35%
0x30 Infite 0x1A 0,052 3,22%
0x01 1,000 43,45% 0x1B 0,047 2,87%
0x11 0,522 28,44% 0x33 0,047 2,82%
0x02 0,500 27,57% 0x26 0,045 2,69%
0x03 0,333 20,08% 0x1C 0,043 2,58%
0x21 0,270 16,83% 0x1D 0,040 2,33%
0x12 0,261 16,33% 0x27 0,039 2,22%
0x04 0,250 15,73% 0x1E 0,037 2,12%
0x05 0,200 12,88% 0x34 0,035 1,95%
0x13 0,174 11,32% 0x1F 0,035 1,93%
0x06 0,167 10,88% 0x28 0,034 1,86%
0x07 0,143 9,38% 0x29 0,030 1,58%
0x31 0,140 9,21% 0x35 0,028 1,43%
0x22 0,135 8,89% 0x2A 0,027 1,35%
0x14 0,130 8,59% 0x2B 0,025 1,17%
0x08 0,125 8,23% 0x36 0,023 1,08%
0x09 0,111 7,32% 0x2C 0,023 1,01%
0x15 0,104 6,86% 0x2D 0,021 0,88%
0x0A 0,100 6,57% 0x37 0,020 0,82%
0x0B 0,091 5,95% 0x2E 0,019 0,77%
0x23 0,090 5,89% 0x2F 0,018 0,67%
0x16 0,087 5,68% 0x38 0,018 0,63%
0x0C 0,083 5,43% 0x39 0,016 0,48%
0x0D 0,077 4,98% 0x3A 0,014 0,36%
0x17 0,075 4,81% 0x3B 0,013 0,26%
0x0E 0,071 4,59% 0x3C 0,012 0,18%
0x32 0,070 4,50% 0x3D 0,011 0,11%
0x24 0,068 4,32% 0x3E 0,010 0,05%
0x0F 0,067 4,26% 0x3F 0,009 0,00%
Note: If the output source conductance (GsCfgCW) has been changed GsCfgMod must also be changed to
get the same modulation index.