MAX1003EVKIT-SO [MAXIM]
User-Selectable ADC Full-Scale Gain Ranges;
| 型号： | MAX1003EVKIT-SO |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | User-Selectable ADC Full-Scale Gain Ranges |
| 文件： | 总8页 (文件大小：93K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1250; Rev 0; 6/97
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
Evluate:2/MAX103
_______________Ge n e ra l De s c rip t io n
____________________________Fe a t u re s
The MAX1002/MAX1003 evaluation kits (EV kits) simplify
e va lua tion of the 60Ms p s MAX1002 a nd 90Ms p s
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.
♦ 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
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.
♦ Square-Pin Header for Easy Connection of Logic
Analyzer to Digital Outputs
♦ User-Selectable ADC Full-Scale Gain Ranges
♦ Fully Assembled and Tested
____________________Co m p o n e n t Lis t
DESIGNATION QTY
DESCRIPTION
______________Ord e rin g In fo rm a t io n
C1, C10,
4
0.01µF, 25V min, 10% ceramic
capacitors
C11, C12
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
BOARD TYPE
Surface Mount
Surface Mount
C2, C3,
4
MAX1002EVKIT-SO
MAX1003EVKIT-SO
47pF, 25V min, 5% ceramic capacitors
C6, C7
0.22µF, 25V min, 10% ceramic
capacitors
C4, C15
2
1
______________Co m p o n e n t S u p p lie rs
5pF, 10V min, 10% ceramic capacitor
(MAX1003)
C5
SUPPLIER*
AVX
PHONE
FAX
22pF, 10V min, 10% ceramic capacitor
(MAX1002)
(803) 946-0690
(847) 639-6400
(617) 564-3100
(603) 224-1961
(803) 626-3123
(847) 639-1469
(617) 564-3050
(603) 224-1430
Coilcraft
M/A-COM
Sprague
C8, C9,
C13, C14
0.1µF, 10V min, 10% ceramic
capacitors
4
2
10µF, 10V min, 20% tantalum caps
AVX TAJC106K016
C16, C17
* Please indicate that you are using the MAX1002/MAX1003
when contacting these component suppliers.
R1
1
2
4
10kΩ, 5% resistor
47kΩ, 5% resistors
49.9Ω, 1% resistors
R2, R3
R4–R7
220nH inductor
Coilcraft 1008CS-221TKBC
_________________________Qu ic k S t a rt
L1
U1
D1
1
1
1
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.
MAX1003CAX, 90Msps
MAX1002CAX, 60Msps
Varactor diode
M/A-COM MA4ST079CK-287, SOT23
1) Connect a +5V power supply to the pad marked
VCC. Conne c t this s up p ly’s g round to the p a d
marked GND.
IIN+, IIN-,
QIN+, QIN-
4
1
4
BNC connectors
None
MAX1002/MAX1003 circuit board
0Ω resistors
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.
JU1, JU2,
JU6, JU7
JU3, JU4,
JU8, JU9
3) Connect a +4V power supply to the pad marked
VTUNE. Connect the supply ground to the GND
pad.
4
2-pin headers
JU5
JU11
J1
1
1
1
1
3-pin header
2-pin header (MAX1002 only)
26-pin connector
Shunt for JU5
4) Remove the shunt from jumper JU5. This sets a
250mVp-p full-scale range.
None
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
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.
MAX1002 Digital Outputs Supply
The MAX1002 uses +5V for its V supply. As with
CCO
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
6) Connect a logic analyzer to connector J1 to monitor
the digital outputs.
7) Turn on all power supplies and signal sources.
the V
and V
supplies by installing jumper JU11,
CC
CCO
8) Observe the digitized analog input signals with the
logic analyzer.
loc a te d ne a r the EV kit p owe r-s up p ly c onne c tors .
However, for best dynamic performance, use separate
analog and digital power supplies.
_______________De t a ile d De s c rip t io n
An a lo g In p u t s
The a na log inp uts to the d ua l ADCs a re p rovid e d
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.
EV Kit J u m p e rs
The MAX1002/MAX1003 EV kits c onta in s e ve ra l
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
DEFAULT
POSITION
JUMPER(S)
FUNCTION
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.
JU1, JU2,
JU6, JU7
Power-supply current-
sense ports
Shorted with 0Ω
resistors
JU3, JU4,
JU8, JU9
Offset-correction
amplifier enabled
Open
Open
Evluate:2/MAX103
ADC full-scale range
selection
ADC Ga in S e le c t io n
The s ing le GAIN-s e le c t p in 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).
JU5
VCCO tied to VCC for
single-supply operation
(MAX1002)
JU11
Open
P o w e r Re q u ire m e n t s
Both the MAX1002 and the MAX1003 require +5V at
Table 2. Gain-Selection Jumper JU5
Settings
about 65mA for their analog V supply. Power-supply
CC
requirements for the digital outputs, however, are differ-
ent for the two devices. 0Ω resistors are installed at
jump e r s ite s J U1, J U2, J U6, a nd J U7, a nd c a n b e
removed to sense device power-supply currents with
an ammeter.
JU5 SETTING
CONNECTION
ADC GAIN RANGE
JU5
1
Pins 1 and 2 shorted Low-gain, 500mVp-p
2
3
MAX1003 Digital Outputs Supply
JU5
1
The MAX1003 requires +3.3V for the V
supply. The
CCO
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.
No pins shorted
Mid-gain, 250mVp-p
2
3
JU5
1
Pins 2 and 3 shorted High-gain, 125mVp-p
2
3
2
_______________________________________________________________________________________
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
Evluate:2/MAX103
Table 3 lists the possible input-drive combinations for
70
68
66
64
62
60
58
56
54
52
50
the mid-gain (250mVp-p) full-scale range selection.
Drive levels are referenced to the open-circuit, com-
mon-mod e volta g e of the a na log inp uts (typ ic a lly
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
OUTPUT
CODE
INPUT DRIVE QIN+ or IIN+
QIN- or IIN-
0
1
2
3
4
5
6
7
8
VTUNE CONTROL VOLTAGE (V)
+125mV
Open Circuit
Open Circuit
Open Circuit
+125mV
0
111111
100000
000000
000000
011111
111111
111111
100000
000000
Single-Ended
Noninverting
0
Figure 1. MAX1002 Oscillator Frequency vs. VTUNE Control
Voltage
-125mV
Open Circuit
Single-Ended
Open Circuit
Inverting
Open Circuit
-125mV
-62.5mV
0
110
105
100
95
+62.5mV
Differential
0
-62.5mV
+62.5mV
90
Offs e t -Co rre c t io n Am p lifie rs
85
The offs e t-c orre c tion a mp lifie rs inc lud e d on the
MAX1002 and MAX1003 are usually enabled in a typi-
cal AC-coupled application circuit. For DC-coupled
a p p lic a tions , the a mp lifie rs mus t b e d is a b le d b y
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-
ure d with the offs e t-c orre c tion a mp lifie rs e na b le d
(jumpers open) and AC-coupled analog inputs.
80
75
70
65
60
0
1
2
3
4
5
6
7
8
VTUNE CONTROL VOLTAGE (V)
Figure 2. MAX1003 Oscillator Frequency vs. VTUNE Control
Voltage
Vo lt a g e -Co n t ro lle d -Os c illa t o r Op e ra t io n
The EV kits inc lud e a volta g e -c ontrolle d -os c illa tor
(VCO) c irc uit to s e t the a na log -to-d ig ita l c onve rte r
(ADC) sampling rate using an external resonant tank
and a varactor diode. A voltage applied to the VTUNE
p a d c ha ng e s the va ra c tor d iod e ’s c a p a c ita nc e 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
e ithe r 60Ms p s for the MAX1002 or 90Ms p s 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’
d yna mic p e rforma nc e . Fig ure s 1 a nd 2 s how the
VTUNE control-voltage typical frequency-adjustment
ranges for the MAX1002 and MAX1003 EV kits, respec-
tively.
_______________________________________________________________________________________
3
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
Dig it a l Ou t p u t s
Table 4. External Clock Source EV Kit
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 c irc uitry. Both d ig ita l outp uts a re up d a te d on
DCLK’s rising edge (see the timing diagram in the
MAX1002 or MAX1003 data sheet).
Modifications
COMPONENT
DESCRIPTION
MODIFICATION
Add
Clock input BNC
connector
Clock Overdrive
C5
5pF capacitor (MAX1003),
22pF capacitor (MAX1002)
Remove
Replace with
0.01µF capaci-
tors
C6, C7
47pF capacitors
_____________La yo u t Co n s id e ra t io n s
L1
220nH inductor
Remove
Remove
R1
10kΩ resistor
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.
Replace with
49.9Ω resistors
R2, R3
D1
47kΩ resistors
Varactor diode
Remove
Ex t e rn a l Clo c k Op e ra t io n
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.
P o w e r S u p p lie s a n d Gro u n d in g
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.
Evluate:2/MAX103
The new 49.9Ω value of R3 shown in Figure 4 provides
proper termination for a 50Ω 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.
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.
The external clock source should have low phase noise
for b e s t d yna mic p e rforma nc e . A low-p ha s e -nois e
sine-wave oscillator serves this purpose well. A square-
wa ve c loc k s ourc e is not ne c e s s a ry to d rive 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.
4
_______________________________________________________________________________________
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
Evluate:2/MAX103
Byp a s s in g
__________Ap p lic a t io n s In fo rm a t io n
To achieve the full dynamic potential from the convert-
ers, minimize the capacitive loading on the digital out-
Prop e r b yp a s s ing is e s s e ntia l to a c hie ve the b e s t
d yna mic p e rforma nc e from the c onve rte rs . The
MAX1002/MAX1003 EV kits use 10µF 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.
p uts to re d uc e the tra ns ie nt c urre nts a t V
a nd
CCO
OGND. The ma ximum c a p a c ita nc e p e r outp ut b it
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
d ig ita l re c e iving c hip ve ry c los e to the MAX1002/
MAX1003 and removing the ground plane from under
the output bit traces.
As the digital outputs toggle, transient currents in the
V
supply can couple into sensitive analog circuitry
and severely degrade the converters’ effective number
of bits performance. Of particular concern is effectively
CCO
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.
bypassing V
to OGND. For best results, locate the
CCO
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.
_______________________________________________________________________________________
5
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
U1
MAX103
(MAX102)
Evluate:2/MAX103
Figure 3. MAX1002/MAX1003 EV Kit Schematic (Voltage-Controlled-Oscillator Mode)
_______________________________________________________________________________________
6
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
Evluate:2/MAX103
U1
MAX103
(MAX102)
Figure 4. MAX1002/MAX1003 EV Kit Schematic (External Clock Operation)
_______________________________________________________________________________________
7
MAX1 0 0 2 /MAX1 0 0 3 Eva lu a t io n Kit s
1.0"
1.0"
Figure 5. MAX1002/MAX1003 EV Kit Component Placement
Guide—Component Side
Figure 6. MAX1002/MAX1003 EV Kit Component Placement
Guide—Solder Side
Evluate:2/MAX103
1.0"
1.0"
Figure 7. MAX1002/MAX1003 EV Kit PC Board Layout—
Component Side
Figure 8. MAX1002/MAX1003 EV Kit PC Board Layout—
Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
8
___________________Ma x im In t e g ra t e d P ro d u c t s , 1 2 0 S a n Ga b rie l Drive , S u n n yva le , CA 9 4 0 8 6 (4 0 8 ) 7 3 7 -7 6 0 0
© 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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