Adcs – Rainbow Electronics MAX1003 User Manual
Page 7
For applications where a DC component of the input
signal is present, Figures 4 and 5 show single-ended
and differential DC-coupled input circuits. The ampli-
fiers’ input common-mode voltage range extends from
1.75V to 2.75V. To prevent attenuation of the input
signal’s DC component in this mode, disable the offset-
correction amplifier by grounding the _OCC+ and
_OCC- pins for the I and Q blocks (Figures 4 and 5).
ADCs
The I and Q ADC blocks receive the analog signals
from the respective I and Q input amplifiers. The ADCs
use flash conversion with 63 fully differential compara-
tors to digitize the analog input signal into a 6-bit output
in offset binary format.
MAX1003
Low-Power, 90Msps, Dual 6-Bit ADC
_______________________________________________________________________________________
7
Figure 2. Single-Ended AC-Coupled Input
Figure 3. Differential AC-Coupled Input
Figure 4. Single-Ended DC-Coupled Input
Figure 5. Differential DC-Coupled Input
MAX1003
INPUT
AMP
20k
2.35V INTERNAL REFERENCE
20k
_IN+
_OCC+
_OCC-
_IN-
0.1
µ
F
0.22
µ
F
V
SOURCE
0.1
µ
F
OFFSET
CORREC-
TION
MAX1003
INPUT
AMP
20k
2.35V INTERNAL REFERENCE
20k
_IN+
_OCC+
_OCC-
_IN-
0.1
µ
F
0.1
µ
F
V
SOURCE
OFFSET
CORREC-
TION
0.22
µ
F
MAX1003
INPUT
AMP
20k
2.35V INTERNAL REFERENCE
20k
_IN+
_OCC+
_OCC-
_IN-
OFFSET CORRECTION DISABLED
V
SOURCE
V
REF
1.75V TO 2.75V
OFFSET
CORREC-
TION
MAX1003
INPUT
AMP
20k
2.35V INTERNAL REFERENCE
20k
_IN+
_OCC+
_OCC-
_IN-
OFFSET CORRECTION DISABLED
V
SOURCE
DIFFERENTIAL SOURCE
WITH COMMON MODE
FROM 1.75V TO 2.75V.
OFFSET
CORREC-
TION