608
FS
Offset error
Nonlinearity
error
Actual A/D conversion
characteristic
Analog
input voltage
Digital output
Ideal A/D conversion
characteristic
Full-scale error
Figure 16-10 A/D Conversion Precision Definitions (2)
Permissible Signal Source Impedance: H8S/2646 Series analog input is designed so that
conversion precision is guaranteed for an input signal for which the signal source impedance is 10
k
Ω
or less. This specification is provided to enable the A/D converter’s sample-and-hold circuit
input capacitance to be charged within the sampling time; if the sensor output impedance exceeds
10 k
Ω
, charging may be insufficient and it may not be possible to guarantee the A/D conversion
precision.
However, if a large capacitance is provided externally, the input load will essentially comprise
only the internal input resistance of 10 k
Ω
, and the signal source impedance is ignored.
However, since a low-pass filter effect is obtained in this case, it may not be possible to follow an
analog signal with a large differential coefficient (e.g., 5 mV/µs or greater).
When converting a high-speed analog signal, a low-impedance buffer should be inserted.
Содержание H8S/2645
Страница 4: ......
Страница 16: ......
Страница 58: ...26 ...
Страница 110: ...78 ...
Страница 120: ...88 ...
Страница 132: ...100 ...
Страница 160: ...128 ...
Страница 172: ...140 ...
Страница 235: ...203 Transfer SAR or DAR DAR or SAR Block area First block Nth block Figure 8 8 Memory Mapping in Block Transfer Mode ...
Страница 418: ...386 ...
Страница 444: ...412 ...
Страница 530: ...498 ...
Страница 562: ...530 ...
Страница 642: ...610 ...
Страница 662: ...630 ...
Страница 688: ...656 ...
Страница 756: ...724 ...
Страница 784: ...752 ...
Страница 812: ...780 ...
Страница 837: ...805 A 2 Instruction Codes Table A 2 shows the instruction codes ...
Страница 1152: ...1120 ...