RHF1201_11 STMICROELECTRONICS [STMicroelectronics], RHF1201_11 Datasheet - Page 25

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

RHF1201
7.3
7.3.1
7.3.2
Note:
Figure 55. External reference setting
VIN
VINB
VCCA
Reference connection
Internal reference
In the standard configuration, the ADC is biased with the internal reference voltage. The
V
1.0 V. V
Figure 54
Figure 54. Internal reference setting
External reference
An external reference voltage can be used for specific applications requiring even better
linearity or enhanced temperature behavior. In such cases, the amplitude of the external
voltage must be at least equal to the internal reference (see
voltage on page
Figure 55
achieved by using ceramic capacitors, which provide optimum linearity versus frequency.
* The use of ceramic technology is preferable for large bandwidth stability of the capacitor.
VREFM
REFM
VREFP
pin is connected to analog ground while V
REFP
As close as possible
the ADC pins
shows the schematics.
and
100 nF*
should be decoupled so as to minimize low and high frequency noise.
Figure 56
10). An external voltage reference with the configuration shown in
470 nF*
VINB
VIN
can be used to obtain optimum performance. Decoupling is
RHF1201
Doc ID 12585 Rev 5
source
VREFM
DC
VREFP
AM04549
Electrical characteristics (unchanged after 300 kRad)
Figure 56. Example with a zener
As close as possible
the ADC pins
100 nF*
*the use of a ceramic technology is
preferable for a large bandwidth
stability of the capacitor.
VINB
VIN
REFP
VCCA
VREFM
is internally set to a voltage close to
470 nF*
As close as possible
the ADC pins
VREFP
Table 7: Internal reference
100 nF*
AM04548
R
470 nF*
AM04550
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