MAX106
±5V, 600Msps, 8-Bit ADC with On-Chip
2.2GHz Bandwidth Track/Hold Amplifier
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In a typical single-ended configuration, the analog
input signal (Figure 10a) enters the T/H amplifier stage
at the in-phase input (VIN+), while the inverted phase
input (VIN-) is reverse-terminated to GNDI with an
external 50Ω resistor. Single-ended operation allows for
an input amplitude of ±250mV. Table 3 shows a selec-
tion of input voltages and their corresponding output
codes for single-ended operation.
Differential Analog Inputs
To obtain a full-scale digital output with differential input
drive (Figure 10b), 250mVp-p must be applied between
VIN+ and VIN- (VIN+ = +125mV and VIN- = -125mV).
Midscale digital output codes (01111111 or 10000000)
occur when there is no voltage difference between
VIN+ and VIN-. For a zero-scale digital output code, the
in-phase input (VIN+) must see -125mV and the invert-
ed input (VIN-) must see +125mV. A differential input
drive is recommended for best performance. Table 4
represents a selection of differential input voltages and
their corresponding output codes.
(NOT SHOWN IN THIS SIMPLIFIED DRAWING).
Figure 10b. Differential Analog Input Signals
Table 3. Ideal Input Voltage and Output Code Results for Single-Ended Operation
0V 11111111 (full scale)+250mV
VIN-
1
OVERRANGE BITVIN+ OUTPUT CODE
0V 11111111+250mV - 1LSB 0
0V
0V
01111111
toggles
10000000
0V 0
00000001 -250mV + 1LSB 0
0V 00000000 (zero scale)-250mV 0
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