Evaluate: MAX1002/MAX1003
5) Using an RF power splitter-combiner, connect a
250mVp-p, 20MHz sine-wave source to both analog
inputs at BNC J3 and J6. The analog input imped-
ance is 50Ω for each channel.
6) Connect a logic analyzer to connector J1 to monitor
the digital outputs.
7) Turn on all power supplies and signal sources.
8) Observe the digitized analog input signals with the
logic analyzer.
_______________Detailed Description
EV Kit Jumpers
The MAX1002/MAX1003 EV kits contain several
jumpers that control board and part options. The follow-
ing sections describe the different jumpers and their
purposes. Table 1 lists the jumpers on the EV kits and
their default positions.
Table 1. EV Kit Jumpers and Default
Positions
Power Requirements
Both the MAX1002 and the MAX1003 require +5V at
about 65mA for their analog V
CC
supply. Power-supply
requirements for the digital outputs, however, are differ-
ent for the two devices. 0Ω resistors are installed at
jumper sites JU1, JU2, JU6, and JU7, and can be
removed to sense device power-supply currents with
an ammeter.
MAX1003 Digital Outputs Supply
The MAX1003 requires +3.3V for the V
CCO
supply. The
current requirement from the power supply is a function
of the sampling clock and analog input frequencies, as
well as the capacitive loading on the digital outputs.
With 15pF loads and a 20MHz analog input frequency
sampled at 90Msps, the current draw is about 10mA.
MAX1002 Digital Outputs Supply
The MAX1002 uses +5V for its V
CCO
supply. As with
the MAX1003, the current requirement is a function of
the analog input frequency and capacitive loading on
the outputs. With 15pF loads and a 20MHz analog input
sampling at 60Msps, the current requirement is about
13mA. You can also use a single power supply for both
the V
CC
and V
CCO
supplies by installing jumper JU11,
located near the EV kit power-supply connectors.
However, for best dynamic performance, use separate
analog and digital power supplies.
Analog Inputs
The analog inputs to the dual ADCs are provided
through BNC connectors IIN+, IIN-, QIN+, and QIN-.
The connectors are terminated with 49.9Ω to ground
and are AC coupled to the converter’s analog inputs,
which are internally self-biased at 2.35V DC. A typical
application circuit drives the IIN+ and QIN+ noninvert-
ing analog inputs using AC-coupled in-phase and quad-
rature signals. The nominal 20kΩ input resistance of the
analog inputs, plus the 0.1µF AC-coupling capacitor
value, sets the low-frequency corner at about 80Hz.
You can drive the analog inputs either single-ended or
differentially using AC- or DC-coupled inputs. Either the
inverting or the noninverting input can be driven single-
ended. If the inverting input is driven, then the digital
output codes are inverted (complemented). Refer to the
MAX1002 or MAX1003 data sheet for typical circuits.
ADC Gain Selection
The single GAIN-select pin on the MAX1002 or
MAX1003 controls the full-scale input range for both the
I and the Q channels. Jumper JU5 is used to manually
select the desired gain range as shown in Table 2. The
EV kits are shipped with the mid-gain range selected
(jumper pins open).
Table 2. Gain-Selection Jumper JU5
Settings
MAX1002/MAX1003 Evaluation Kits
2 _______________________________________________________________________________________
Open
Offset-correction
amplifier enabled
JU3, JU4,
JU8, JU9
Shorted with 0Ω
resistors
Power-supply current-
sense ports
JU1, JU2,
JU6, JU7
DEFAULT
POSITION
FUNCTIONJUMPER(S)
Open
VCCO tied to VCC for
single-supply operation
(MAX1002)
JU11
Open
ADC full-scale range
selection
JU5
Mid-gain, 250mVp-p
No pins shorted
Low-gain, 500mVp-pPins 1 and 2 shorted
ADC GAIN RANGECONNECTIONJU5 SETTING
High-gain, 125mVp-pPins 2 and 3 shorted
