_________________________Quick Start

The MAX1002/MAX1003 EV kits are fully assembled
and tested. Follow these steps to verify proper board
operation.

Do not turn on the power supplies until all

connections to the EV kit are completed.

1) Connect a +5V power supply to the pad marked

VCC. Connect this supply's ground to the pad
marked GND.

2) Connect a +3.3V (MAX1003) or +5V (MAX1002)

power supply to the pad labeled VCCO. Connect
the supply ground to the pad marked OGND.

3) Connect a +4V power supply to the pad marked

VTUNE. Connect the supply ground to the GND
pad.

4) Remove the shunt from jumper JU5. This sets a

250mVp-p full-scale range.

_______________General Description

The MAX1002/MAX1003 evaluation kits (EV kits) simplify
evaluation of the 60Msps MAX1002 and 90Msps
MAX1003 dual, 6-bit analog-to-digital converters (ADCs).
The kits include the basic components necessary to
operate the on-chip oscillator as a voltage-controlled
oscillator (VCO). Each board can also be easily modified
to accommodate an external clocking source.

Connectors for power supplies, analog inputs, and digital
outputs simplify connections to the device. The PC board
features an optimized layout to ensure the best possible
dynamic performance. The EV kits include a MAX1002 or
MAX1003.

____________________________Features

5.85 Effective Number of Bits at 20MHz Analog
Input Frequency

Separate Analog and Digital Power and Ground
Connections with Optimized PC Board Layout

Matched Single-Ended or Differential Analog
Inputs for Both I and Q Channels

Square-Pin Header for Easy Connection of Logic
Analyzer to Digital Outputs

User-Selectable ADC Full-Scale Gain Ranges

Fully Assembled and Tested

Evaluate: MAX1002/MAX1003

MAX1002/MAX1003 Evaluation Kits

________________________________________________________________

Maxim Integrated Products

19-1250; Rev 0; 6/97

QTY

DESCRIPTION

C1, C10,

C11, C12

C2, C3,

C6, C7

C4, C15

0.22礔, 25V min, 10% ceramic
capacitors

C8, C9,

C13, C14

0.1礔, 10V min, 10% ceramic
capacitors

R2, R3

R4璕7

220nH inductor
Coilcraft 1008CS-221TKBC

MAX1003CAX, 90Msps

Varactor diode
M/A-COM MA4ST079CK-287, SOT23

IIN+, IIN-,

QIN+, QIN-

BNC connectors

None

MAX1002/MAX1003 circuit board

5pF, 10V min, 10% ceramic capacitor
(MAX1003)

47pF, 25V min, 5% ceramic capacitors

0.01礔, 25V min, 10% ceramic
capacitors

SUPPLIER*

PHONE

FAX

AVX

(803) 946-0690

(803) 626-3123

______________Component Suppliers

DESIGNATION

10k

, 5% resistor

47k

, 5% resistors

49.9

, 1% resistors

____________________Component List

______________Ordering Information

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800

Coilcraft

(847) 639-6400

(847) 639-1469

M/A-COM

(617) 564-3100

(617) 564-3050

Sprague

(603) 224-1961

(603) 224-1430

JU1, JU2,

JU6, JU7

resistors

JU3, JU4,

JU8, JU9

2-pin headers

JU5

3-pin header

JU11

2-pin header (MAX1002 only)

26-pin connector

None

Shunt for JU5

22pF, 10V min, 10% ceramic capacitor
(MAX1002)

MAX1002CAX, 60Msps

Please indicate that you are using the MAX1002/MAX1003
when contacting these component suppliers.

PART

MAX1002EVKIT-SO

MAX1003EVKIT-SO

0癈 to +70癈

TEMP. RANGE

BOARD TYPE

Surface Mount

C16, C17

10礔, 10V min, 20% tantalum caps
AVX TAJC106K016

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 50

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

supply. Power-supply

requirements for the digital outputs, however, are differ-
ent for the two devices. 0

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

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 49.9

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 20k

input resistance of the

analog inputs, plus the 0.1礔 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

_______________________________________________________________________________________

Open

Offset-correction
amplifier enabled

JU3, JU4,

JU8, JU9

Shorted with 0

resistors

Power-supply current-
sense ports

JU1, JU2,

JU6, JU7

DEFAULT

POSITION

FUNCTION

JUMPER(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-p

Pins 1 and 2 shorted

ADC GAIN RANGE

CONNECTION

JU5 SETTING

High-gain, 125mVp-p

Pins 2 and 3 shorted

JU5

Table 3 lists the possible input-drive combinations for
the mid-gain (250mVp-p) full-scale range selection.
Drive levels are referenced to the open-circuit, com-
mon-mode voltage of the analog inputs (typically
2.35V) if DC coupled, or to ground if AC coupling is
used. If the low-gain (500mVp-p) range is selected, the
input-drive requirements are twice those listed in Table
3. If the high-gain (125mVp-p) range is selected, the
input-drive requirements are half those listed in Table 3.

Table 3. Typical Input-Drive Requirements
for Mid-Gain

Offset-Correction Amplifiers

The offset-correction amplifiers included on the
MAX1002 and MAX1003 are usually enabled in a typi-
cal AC-coupled application circuit. For DC-coupled
applications, the amplifiers must be disabled by
installing shorting blocks on jumpers JU3, JU4 (I chan-
nel); and JU8, JU9 (Q channel). These jumpers short
device pins IOCC+ (pin 2), IOCC- (pin 3), QOCC- (pin
16), and QOCC+ (pin 17) to ground and disable the
amplifiers. The MAX1002/MAX1003 EV kits are config-
ured with the offset-correction amplifiers enabled
(jumpers open) and AC-coupled analog inputs.

Voltage-Controlled-Oscillator Operation

The EV kits include a voltage-controlled-oscillator
(VCO) circuit to set the analog-to-digital converter
(ADC) sampling rate using an external resonant tank
and a varactor diode. A voltage applied to the VTUNE
pad changes the varactor diode's capacitance to
adjust the tank's resonant frequency, which sets the
oscillator's sampling frequency. VTUNE voltage can be
varied from 0V to a maximum of 8V.

The EV kits are designed so that a nominal VTUNE con-
trol voltage of about 4V sets the ADC sampling rate to
either 60Msps for the MAX1002 or 90Msps for the
MAX1003. The VTUNE control voltage should be well
filtered, as any noise on the supply contributes to jitter
in the internal oscillator and degrades the converters'
dynamic performance. Figures 1 and 2 show the
VTUNE control-voltage typical frequency-adjustment
ranges for the MAX1002 and MAX1003 EV kits, respec-
tively.

Evaluate: MAX1002/MAX1003

MAX1002/MAX1003 Evaluation Kits

_______________________________________________________________________________________

INPUT DRIVE

Single-Ended

Noninverting

+125mV

QIN+ or IIN+

-125mV

Open Circuit

QIN- or IIN-

Open Circuit

100000

111111

OUTPUT

CODE

000000

Open Circuit

+125mV

-125mV

Single-Ended

Inverting

011111

000000

111111

+62.5mV

-62.5mV

+62.5mV

Differential

100000

111111

000000

MAX100/1003-fig1

VTUNE CONTROL VOLTAGE (V)

FREQUENCY (MHz)

Figure 1. MAX1002 Oscillator Frequency vs. VTUNE Control
Voltage

105

100

110

MAX100/1003-fig2

VTUNE CONTROL VOLTAGE (V)

FREQUENCY (MHz)

Figure 2. MAX1003 Oscillator Frequency vs. VTUNE Control
Voltage

Evaluate: MAX1002/MAX1003

External Clock Operation

The MAX1002/MAX1003 EV kits can be converted to
drive the ADCs from an external clock source. This
involves removing the external resonator components
from the VCO circuit and adding a few new compo-
nents. Table 4 lists the EV kit changes required to con-
vert the board to accept an external clock source. The
resulting schematic is shown in Figure 4.

The new 49.9

value of R3 shown in Figure 4 provides

proper termination for a 50

external signal generator.

AC-coupling capacitor C6 couples the external clock
signal to the MAX1002/MAX1003 oscillator circuitry at
TNK+ (pin 9). R2 and C7 ensure that the impedance at
both ports of the oscillator is balanced. After all modifi-
cations are complete, connect an external clock source
to the BNC connector on the EV kit marked CLOCK
OVERDRIVE. The recommended clock amplitude is
1Vp-p; however, the ADC operates correctly with as lit-
tle as 100mVp-p or up to 2.5Vp-p on CLOCK OVER-
DRIVE.

The external clock source should have low phase noise
for best dynamic performance. A low-phase-noise
sine-wave oscillator serves this purpose well. A square-
wave clock source is not necessary to drive the
MAX1002/MAX1003. The devices contain sufficient
gain to amplify even a low-level-input sine wave to drive
the ADC comparators, while ensuring excellent dynam-
ic performance.

Digital Outputs

The TTL/CMOS-compatible digital outputs are present-
ed in parallel from both I and Q channels at connector
J1. The data format is offset binary with the MSB as D5
and the LSB as D0. The row of pins closest to the
board edge is digital output ground (OGND), while the
data bits occupy the inside row. Located in the middle
of the connector is the pin for the output clock labeled
DCLK. This signal can be used to latch the parallel out-
put data for capture into a logic analyzer or external
DSP circuitry. Both digital outputs are updated on
DCLK's rising edge (see the timing diagram in the
MAX1002 or MAX1003 data sheet).

_____________Layout Considerations

The MAX1002/MAX1003 EV kit layouts have been opti-
mized for high-speed signals. Careful attention has
been given to grounding, power-supply bypassing, and
signal-path layout to minimize coupling between the
analog and digital sections of the circuit. For example,
the ground plane has been removed under the tank cir-
cuitry to reduce stray capacitive loading on the relative-
ly small capacitors required in the external resonant
tank formed by C5, L1, and D1. Other layout considera-
tions are detailed in the following sections.

Power Supplies and Grounding

The EV kits feature separate analog and digital power
supplies and grounds for best dynamic performance. A
thin trace located on the backside of the circuit board
near the VCC power-supply connector ties the analog
and output ground planes together. This trace can be
cut if the power-supply grounds are referenced else-
where.

Referencing analog and digital grounds together at a
single point usually avoids ground loops and corruption
of sensitive analog circuitry by noise from the digital
outputs. If the ground trace on the backside of the
board is cut, observe the absolute maximum ratings
between the two grounds.

MAX1002/MAX1003 Evaluation Kits

_______________________________________________________________________________________

5pF capacitor (MAX1003),
22pF capacitor (MAX1002)

Clock input BNC
connector

DESCRIPTION

47pF capacitors

COMPONENT

Clock Overdrive

C6, C7

Remove

Add

MODIFICATION

Replace with
0.01礔 capaci-
tors

10k

resistor

220nH inductor

Remove

47k

resistors

Replace with
49.9

resistors

R2, R3

Varactor diode

Remove

Table 4. External Clock Source EV Kit
Modifications

Bypassing

Proper bypassing is essential to achieve the best
dynamic performance from the converters. The
MAX1002/MAX1003 EV kits use 10礔 bypass capaci-
tors located close to the power-supply connectors on
the board to filter low-frequency supply ripple. High-fre-
quency bypassing is accomplished with ceramic chip
capacitors located very close to the device's supply
pins.

As the digital outputs toggle, transient currents in the
V

CCO

supply can couple into sensitive analog circuitry

and severely degrade the converters' effective number
of bits performance. Of particular concern is effectively
bypassing V

CCO

to OGND. For best results, locate the

bypass capacitors on the same side of the board and
place them close to the device. This avoids the use of
through-holes and results in lower series inductance.
The capacitor size chosen for the EV kits (size 0603)
keeps the layout compact. Finally, the modest value
(47pF) and small size result in a high self-resonant fre-
quency for effective high-frequency bypassing.

__________Applications Information

To achieve the full dynamic potential from the convert-
ers, minimize the capacitive loading on the digital out-
puts to reduce the transient currents at V

CCO

and

OGND. The maximum capacitance per output bit
should be less than 15pF. For example, the capaci-
tance of the digital output traces and the J1 connector
on the EV kits is about 3pF per trace. In an applications
circuit, this could be further reduced by locating the
digital receiving chip very close to the MAX1002/
MAX1003 and removing the ground plane from under
the output bit traces.

A logic analyzer can be connected to the J1 connector
on the EV kits for evaluation purposes. The analyzer
should be directly connected to the EV kit without any
additional ribbon cables. Even a short length of ribbon
cable can exceed the maximum recommended capaci-
tive loading of the digital outputs. A typical high-speed
logic analyzer probe adds about another 8pF loading
per digital bit, which is acceptable for good dynamic
performance.

Evaluate: MAX1002/MAX1003

MAX1002/MAX1003 Evaluation Kits

_______________________________________________________________________________________

协谢械泻褌褉芯薪薪褘泄 泻芯屑锌芯薪械薪褌: MAX1002EVKIT-SO

协谢械泻褌褉芯薪薪褘泄泻芯屑锌芯薪械薪褌: MAX1002EVKIT-SO