adc1020 austriamicrosystems, adc1020 Datasheet - Page 8

• Manufacturer Part Number: adc1020
• Description: Cmos 10-bit Pipelined A/d Converter
• Manufacturer: austriamicrosystems

Datasheet : ADC1020 – C35
SYSTEM REQUIREMENTS
The ADC is sensitive to ground noise. So all parts of the whole system except the ADC should be quiet during the conversions. To minimize
ground noise coming from digital output pads the connection of a series resistor should be used to limit the switching current. In the test circuit a
series resistor of 1kΩ is used for the digital output bus.
CONVERSION MODES
The converter operates with fully-differential or single-ended inputs. The best performance of this ADC is reached for fully-differential inputs.
Single Ended Mode
To use the ADC1020 as a Single Ended Converter the input VINN must be connected to VCM. In this case the ADC performs a single-ended to
fully-differential conversion. The second input VINP should be balanced around VCM.
Fully Differential Mode
To use the ADC1020 as a Fully Differential Converter both inputs VINP and VINN should be balanced around VCM.
CODE TABLES
The digital representation of the data bus in both conversion modes is described in the following table.
Offset Binary
Revision C, 07.09.02
VREF
=
VREFP
−
VREFN
Output Code
11 1111 1111
11 1111 1110
…
10 0000 0001
10 0000 0000
01 1111 1111
01 1111 1110
…
00 0000 0001
00 0000 0000
,
1
LSB
=
VREFP
512
−
VREFN
Input Voltage: VIN-VINB
511LSB … VREF
510LSB … 511LSB
…
1LSB … 2LSB
0 … 1LSB
-1LSB … 0
-2LSB … -1LSB
…
-511LSB … -510LSB
-VREF … -511LSB
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