MAX1011 Datasheet, PDF (6/12 Pages) Maxim Integrated Products – Low-Power, 90Msps, 6-Bit ADC

Low-Power, 90Msps, 6-Bit ADC
amplifier inputs is internally biased to a 2.35V reference
through a 20kΩ resistor, eliminating external DC bias
circuits. A series 0.1µF capacitor is required at the
amplifier input for AC-coupled signals.
When operating with AC-coupled inputs, the input
amplifier’s DC offset voltage is nulled to within ±1/2LSB
by an on-chip, offset-correction amplifier. An external
compensation capacitor is required to set the dominant
pole of the offset-correction amplifier’s frequency
response (Figures 2 and 3). The compensation capaci-
tor will determine the low-frequency corner of the ana-
log input response according to the following formula:
f_c = 1 / (0.1 x C)
where C is the value of the compensation capacitor in
µF, and f_c is the corner frequency in Hz.
RF
LO
MAX1011
6 BITS
DATA
BUFFER
6
DCLK
DIGITAL
DEMODULATOR
OR
DSP
TANK
Figure 1. IF Sampling Receiver
0.1µF
IN+
V_SOURCE
IN-
0.1µF
20k
0.22µF
OCC+
OCC-
OFFSET
CORREC-
TION
INPUT
AMP
20k
MAX1011
2.35V INTERNAL REFERENCE
0.1µF _IN+
V_SOURCE
IN-
0.1µF
20k
0.22µF
OCC+
OCC-
OFFSET
CORREC-
TION
INPUT
AMP
20k
MAX1011
2.35V INTERNAL REFERENCE
Figure 2. Single-Ended AC-Coupled Input
Figure 3. Differential AC-Coupled Input
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