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_______________General Description

The MAX101A evaluation kit (EV kit) was developed to
assist in the initial evaluation of the MAX101A high-
speed analog-to-digital converters (ADCs). The EV kit is
a two-board set comprised of a main board and a ter-
mination board.

The main board contains all the circuitry needed to
evaluate the initial performance of this flash converter,
which combines high-speed analog and digital circuitry
and requires special attention to circuit layout. In con-
junction with the MAX101A, the main board allows digi-
tizing of analog signals at up to 500Msps. It has provi-
sions for an external clock source, which is supplied
through an SMA connector. The analog inputs to the
converter are through two SMA connectors (AIN+ and
AIN-). There are 16 data outputs (two 8-bit words) plus
the data clock output.

A separate termination board with 50

ECL pull-down

resistors is provided with the kit and is connected to the
main board with a 3x32 pin EURO-card connector. It
provides access to the converter output data, as well
as proper ECL termination. The termination board also
has two ranks of square pins, each providing eight data
outputs, plus data clock outputs. Either AData or BData
can be observed with a high-speed logic analyzer.

Standard power supplies of +5V and -5.2V are needed
to operate the MAX101A main board. Power can be
supplied through the 3x32 EURO-card connector or
through the pads on the edge of the board. Nominal
power dissipation for both boards is 17W. The board
set comes fully assembled and tested, with the
MAX101A installed.

The MAX101A EV kit comes with a MAX101A installed
on the board, but it can also be used to evaluate the
MAX101. Refer to instructions for setting references
and input conditions for the appropriate device version
throughout this document.

____________________________Features

7.0 Effective Bits at 250MHz

On-Board Reference Generator/Buffer

Input through SMA Coaxial Connectors

Dual Differential-Output Data Paths

±270mV Input Signal Range (MAX101)
±250mV Input Signal Range (MAX101A)

Buffered Differential 100k ECL Outputs

3x32 Pin EURO-Card Connector

Evaluates: MAX101/MAX101A

MAX101A Evaluation Kit

________________________________________________________________

Maxim Integrated Products

19-0342; Rev 1; 7/96

PART

TEMP. RANGE

BOARD TYPE

MAX101AEVKIT-CFR

0°C to +70°C

Surface Mount

______________Ordering Information

____________________Component List

DESIGNATION

QTY

DESCRIPTION

C1, C2, C4, C6, C7,

C9, C10, C12, C14,

C15, C18, C20, C23,
C26, C27, C29, C31,

C32, C34, C36,

C38, C40, C42

0.01µF capacitors

C3, C5, C11, C13

0.22µF capacitors

C8, C16, C30, C33,

C35, C37, C39,

C41, C43

100pF capacitors

C17, C21, C24

0.1µF capacitors

C19, C22, C25

10µF capacitors,
AVX "D" tantalum

D1D4

100mA Schottky diodes,
Central Semiconductor
CMPSH-3

DIV 10

3-pin jumper block

J1, J2, J3

Female SMA connectors

96-pin EURO-style plug

L1, L2

Ferrite beads

R1, R12

180

, 1% resistors

R2, R13, R23

121

, 1% resistors

R3, R4, R14, R15

100

trim pots

R5, R16, R38, R39

, 5% resistors

Component List continued on next page.

Evaluates: MAX101/MAX101A

MAX101A Evaluation Kit

_______________________________________________________________________________________

_________________________Quick Start

Plug the termination board into the 96-pin connec-
tor of the MAX101A main board.

Use a fan to provide at least 200 lineal feet/min air-
flow to the heatsink of the MAX101A.

Connect the power supplies. The power-supply
input pads are in the lower right-hand corner of the
MAX101A main board. The board requires a 20W
power supply that provides +5V and -5.2V with a
common ground.

Turn on the -5.2V power supply first, followed by
the +5V power supply. The -5.2V power supply
should be the first supply turned on and the last
supply turned off.

Connect a low-phase-jitter RF source with a level
range of -4dBm to +10dBm to the clock input.

Connect a test signal to the analog inputs. Use
IN+ and IN- if the signal is differential, or IN+ if the
signal is single-ended (±270mV (MAX101),
±250mV (MAX101A) differential; see the MAX101
or MAX101A data sheet).

Observe the digitized results on the termination
board pins by using a logic analyzer, such as the
HP16500 series or an equivalent data-acquisition
system. The outputs are 100k ECL compatible.

_______________Detailed Description

Board Set

The MAX101A EV kit is a two-board set. The main board
contains ECL-interface circuitry and the MAX101A ADC.
The termination board provides high-speed signal termi-
nation and access to the digital data. For further signal
processing, the main board can be plugged into a larger
system board via the provided EURO-card connector.

Clock Input

The external clock input is capacitively coupled to an on-
board bias network. Take care to ensure that the pulse
width is within the specified requirements: clock input
levels should be -4dBm to +10dBm, and clock frequency
can range from 250MHz to 500MHz. Figure 1 in the
MAX101A data sheet shows the necessary timing
requirements for the clock input, as well as the
expected output clock waveforms. The clock input
should be driven by a low-jitter RF signal source. Refer
to Figures 1, 2, and 3 of the MAX101A data sheet for
more information.

Analog Input

Analog input to the MAX101A is made through one or
both of the two SMA coaxial connectors provided (AIN+
and AIN- inputs). Each input is a direct connection to the
ADC, with internal 50

terminations provided by the

MAX101A.

Outputs

The MAX101A main board has two 8-bit-wide digital
outputs that are 100k ECL compatible. Each data out-
put is buffered by 100E116 line receivers. There is also
a data clock output (DCLK) provided for timing. All 17
outputs provided to the EURO-card connector are dif-
ferential and unterminated.

The termination board provides a termination for each
data line, through 50

to -2V.

ADC Reference Resistor String

An on-board reference supply and op-amp circuit drive
the ADC reference resistor string. The reference sup-
plies can be adjusted using the four potentiometers on
the board (see the

Calibration Procedure). It is impor-

tant to ensure that a reverse bias condition never occurs
on the reference inputs. Schottky diode clamps on the
reference amp outputs help protect the MAX101A.

DIV 10

The jumper DIV 10 selects the operating mode of the
MAX101A, which can output data either at full speed or
at 1/10 the clock rate. This feature is valuable during
initial testing. DIV 10 is usually left open for normal (full-

DESIGNATION

QTY

DESCRIPTION

_______Component List (continued)

R6, R7, R17, R18

, 5% resistors

R8, R9, R19, R20

12.1k

, 1% resistors

R10, R11, R21, R22

27.4

, 1% resistors

R24, R34, R36

82.5

, 1% resistors

R25

, 1% resistor

R26

trim pot

R27

3.16k

, 1% resistor

R28, R29, R40R55

100

, 5% resistors

R35, R37

221

, 1% resistors

Maxim MAX101ACFR

U2, U4

Maxim MAX412CPA high-
speed dual op amps

U3, U5

Maxim MX580KH 2.5V
references

LM337T negative voltage
regulator

U8, U21U24

MC100E116 quintuple line
receivers

speed) operation.

Power Supplies

The following supplies are required for normal opera-
tion of the main board:

= +5V at 0.8A

and V

= -5.2V at 2.5A

These voltages should be supplied to the connector pins
for V

, V

, and V

, respectively. V

and V

are

connected on the board with a ferrite bead. If system
noise must be reduced, you may remove this bead and
then provide the analog supply, V

, separately from the

digital supply, V

. The -5.2V power supply should be the

first supply turned on and the last supply turned off.

Board Layout

The MAX101A requires proper PC board layout for
device operation. This section explains the layout
requirements and demonstrates how the EV kit
achieves these goals.

Use power and ground planes to deliver power to the
device, keeping the digital planes separate from the
analog planes. The EV kit uses layers 3, 4, and 5 for
power and ground planes. Tie digital ground and ana-
log ground to a single point, as close to the power sup-
ply as possible. On the EV kit, digital ground ties to ana-
log ground at ferrite bead L1. Likewise, tie digital power
(V

) and analog power (V

) to a single point, as close

to the power supply as possible. On the EV kit, digital
power ties to analog -5.2V power at ferrite bead L2.

Use transmission lines for the analog input, clocks, and
high-speed digital outputs. The MAX101A EV kit uses
microstrip lines of two different impedances. The
MAX101A data outputs drive differential line drivers
through 100

microstrip lines. The 50

microstrip lines

occupy layers 1 and 2. The 100

microstrip lines occu-

py layers 1 and 3, with layer 2 void. The kit uses FR4
epoxy dielectric material, whose relative dielectric con-
stant is between 4.1 and 4.9. The nominal design is
0.0014 inch (0.0355mm) foil thickness for each copper
layer, and 0.011 inch (0.28mm) dielectric thickness
between layers. The 50

microstrip lines have a signal

trace width of 0.020 inch (0.50mm), and the 100

microstrip lines have a signal trace width of 0.010 inch
(0.25mm). Refer to Motorola's MECL or ECLinPS data
book for an introduction to interconnect design.

Due to the high-speed nature of this part, the propaga-
tion delay of the PC board traces becomes a significant
design consideration. For the EV kit design, the propa-
gation delay is approximately 145ps per inch
(5.7ps/mm). For best results, try to match the lengths of
the data traces to within 0.5 inch (12mm). The clock
signal must be routed on one layer only, without using
any through-hole vias. The MAX101A EV kit is a con-
trolled impedance board (50

and 100

) and has a

total board thickness of 0.062 inches (1.57mm) using
six copper layers (see Figure 1, the Layer Profile).

Evaluating the MAX101

The MAX101A EV kit also can be used to evaluate
the MAX101.

To use the MAX101, refer to specific instructions in the
Quick Start, Applications Information, and Calibration
Procedure sections.

Evaluates: MAX101/MAX101A

MAX101A Evaluation Kit

_______________________________________________________________________________________

Copper Layer 1

Copper thickness = 0.0007" (

copper) (microstrip signals)

Epoxy FR4