RHF1201_11 STMICROELECTRONICS [STMicroelectronics], RHF1201_11 Datasheet - Page 24

• Manufacturer Part Number: RHF1201_11
• Description: Rad-hard 12-bit 50 Msps A/D converter
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Electrical characteristics (unchanged after 300 kRad)
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Cin and R behave like a high-pass filter and are calculated to set the lowest possible cut-off
frequency. An example of VINB decoupling to reduce noise is shown in
Figure 52. AC-coupling single-ended input configuration
Figure 53. AC-coupling single-ended input configuration for low frequencies
The C capacitor (in the range of 33 pF for example) is dedicated to a low input frequency
range. This capacitor is efficient in reducing noise at higher frequencies. When coupled with
the resistors, R and C together behave like a high-pass filter. For example, if R = 10 k and
C = 33 pF, the cut-off frequency of this filter equals 482 kHz.
Analog input signal
Analog input signal
(50 Ω output)
(50 Ω output)
50 Ω track
50 Ω track
50 Ω
*ceramic technology for a large
bandwidth stability of the capacitor
50 Ω
Doc ID 12585 Rev 5
ceramic*
470 pF
*the use of a ceramic technology is
preferable for a large bandwidth
stability of the capacitor
C
Cin
Short track
Short track
ceramic*
100 nF
Short track
R
R
R
R
Short track
100 nF ceramic*
(as close as possible
to INCM pin)
100 nF ceramic*
(as close as possible
to INCM pin)
INCM
INCM
VIN
VINB
VINB
VIN
RHF1201
RHF1201
External INCM
(optional)
External INCM
(optional)
Figure
AM04547
AM04546
52.
RHF1201