MAXIM MAX5888EVKIT

19-2867; Rev 0; 5/03
MAX5888 Evaluation Kit
Ordering Information
PART
TEMP RANGE
MAX5888EVKIT
0°C to +70°C
Features
♦ Quick Dynamic Performance Evaluation
♦ LVDS Compatible
♦ SMA Coaxial Connectors for Clock Input and
Analog Output
♦ 50Ω Matched Clock Input and Analog Output
Signal Lines
♦ Single-Ended to Differential Clock-Signal
Conversion Circuitry
♦ Differential Current Output to Single-Ended
Voltage Signal Output Conversion Circuitry
♦ Full-Scale Current Output Configured for 20mA
IC PACKAGE
♦ External 1.25V Reference Source Available
68 QFN-EP*
♦ Fully Assembled and Tested
*EP = Exposed pad.
♦ Evaluates the 16-Bit MAX5888, 14-Bit MAX5887,
and 12-Bit MAX5886 DACs
Component List
DESIGNATION
C1
C2–C15
C16, C28
C17, C20, C23
DESIGNATION
QTY
0
Not installed, ceramic capacitor
(0603)
R1–R4
4
100Ω ±0.1% resistors (0603)
R5
1
100Ω ±1% resistor (0603)
R6, R8, R9
0
Not installed, resistors (0603)
14
0.1µF ±10%, 10V X5R ceramic
capacitors (0402)
TDK C1005X5R1A104KT or
Taiyo Yuden LMK105BJ104KV
R7
1
2kΩ ±1% resistor (0603)
R10, R11
2
24.9Ω ±1% resistors (0402)
R12, R13
2
0Ω ±5% resistors (0402)
0
Not installed, ceramic capacitors
(0805)
L1–L4
4
Ferrite bead cores (4532)
Panasonic EXC-CL-4532U1
T1, T3
2
3
47µF ±10%, 6.3V tantalum capacitors
(B)
AVX TAJB476K006R or
Kemet T494B476K006AS
Transformers
Mini-Circuits ADTL1-12
T2
1
1:1 balun transformer
Coilcraft TTWB3010-1
CLK, OUT
2
SMA PC-mount vertical connectors
2
Scope probe connectors
Tektronix 131-4244-00 (100 quantity)
QTY
DESCRIPTION
10µF ±10%, 10V tantalum capacitors
(A)
AVX TAJA106K010R or
Kemet T494A106K010AS
C18, C21, C24,
C26
4
C19, C22, C25,
C27
4
1µF ±10%, 10V X5R ceramic
capacitors (0603)
TDK C1608X5R1A105KT
J1, J2
2
2 x 20-pin surface-mount headers
(0.1in)
Samtec TSM-120-02-S-MT
JU1–JU5
5
2-pin headers
OUT+, OUT-
DESCRIPTION
TP1, TP2, TP3
3
PC test points, black
TP4
U1
1
1
PC test point, red
MAX5888EGK (68-pin QFN-EP)
U2
1
1.25V voltage reference (8-pin SO)
Maxim MAX6161AESA
None
5
Shunts (JU1–JU5)
None
1
MAX5888 PC board
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
Evaluates: MAX5886/MAX5887/MAX5888
General Description
The MAX5888 evaluation kit (EV kit) is a fully assembled
and tested circuit board that contains all the components necessary to evaluate the performance of the
MAX5888 16-bit, 500Msps, current-output, digital-toanalog converter (DAC). The EV kit requires low-voltage
differential-signaling (LVDS)-compatible data input, a
single-ended clock input, and 3.3V power supplies for
simple board operation.
The MAX5888 EV kit may also be used to evaluate the
MAX5887 (14-bit) and MAX5886 (12-bit) DACs.
Evaluates: MAX5886/MAX5887/MAX5888
MAX5888 Evaluation Kit
Component Suppliers
SUPPLIER
PHONE
FAX
WEBSITE
AVX
843-946-0238
843-626-3123
www.avxcorp.com
Coilcraft
847-639-6400
847-639-1469
www.coilcraft.com
Kemet
864-963-6300
864-963-6322
www.kemet.com
Mini-Circuits
718-934-4500
718-934-7092
www.minicircuits.com
Panasonic
714-373-7366
714-737-7323
www.panasonic.com
Samtec
812-944-6733
812-948-5047
www.samtec.com
Taiyo Yuden
800-348-2496
847-925-0899
www.t-yuden.com
TDK
847-803-6100
847-390-4405
www.component.tdk.com
Note: Please indicate that you are using the MAX5888 when contacting these component suppliers.
Quick Start
Recommended equipment:
• Three 3.3VDC power supplies
• Function generator with low phase noise and low jitter
for clock input (e.g., HP 8662A)
• 16-bit digital pattern generator for LVDS data inputs
(e.g., Agilent 81250)
• Spectrum analyzer (e.g., Rohde & Schwartz FSEA30)
• Voltmeter
The MAX5888 EV kit is a fully assembled and tested surface-mount board. Follow the steps below for board
operation. Do not turn on power supplies or enable
signal generators until all connections are completed:
1) Verify that no shunts are installed across jumpers
JU1, JU2 (DAC uses the 1.2V internal voltage reference), and JU3 (DAC in normal operation mode).
2) Verify that a shunt is installed across jumper JU4.
3) Verify that no shunt is installed across jumper JU5.
4) Synchronize the digital pattern generator (HP
81250) to the clock function generator (HP 8662A).
5) Connect the clock function signal generator to the
CLK SMA connectors on the EV kit.
6) Verify that the 16-bit digital pattern generator is programmed for LVDS outputs.
7) Connect the digital pattern generator output to the
input header connectors J1 and J2 on the EV kit
board. The input header pins are labeled for proper
connection with the digital pattern generator (i.e.,
connect the positive rail of bit 0 to the header pin
labeled B0P and complementary negative rail to the
header pin labeled B0N, etc.).
2
8) Connect the spectrum analyzer to the OUT SMA
connector.
9) Connect a 3.3V power supply to VDD_CK. Connect
the ground terminal of this supply to GND_CK.
10) Connect a 3.3V power supply to DVDD. Connect
the ground terminal of this supply to DGND.
11) Connect a 3.3V power supply to AVDD. Connect
the ground terminal of this supply to AGND.
12) Turn on the three power supplies.
13) With a voltmeter verify that 1.2V is measured at the
VREF PC board pad on the EV kit.
14) Enable the clock function generator and the digital
pattern generator. Set the clock function generator
output power to 10dBm and the frequency (fCLK) to
less than or equal to 500MHz.
15) Use the spectrum analyzer to view the MAX5888
output spectrum or view the output waveform using
an oscilloscope.
Detailed Description
The MAX5888 EV kit is designed to simplify the evaluation of the MAX5888 16-bit, 500Msps, current-output
DAC. The MAX5888 requires LVDS-compatible data
inputs, differential clock input signals, a 1.2V reference
voltage, and 3.3V power supplies for simple board
operation.
The MAX5888 EV kit provides header connectors to
easily interface with an LVDS pattern generator, circuitry to convert the differential current outputs to a singleended voltage signal, and circuitry to convert a usersupplied single-ended clock signal to a differential
clock signal required by the DAC. The EV kit circuit
includes different options for supplying a reference voltage to the DAC. The EV kit circuit can operate with a
single 3.3V power supply, but also supports the use of
_______________________________________________________________________________________
MAX5888 Evaluation Kit
Power Supplies
The MAX5888 EV kit can operate from a single 3.3V
power supply connected to the VDD_CK, DVDD, AVDD
input power pads and their respective ground pads for
simple board operation. However, three separate 3.3V
power supplies are recommended for optimum dynamic
performance. The EV kit board layout is divided into three
sections: digital, analog, and digital clock circuits. Using
separate power supplies for each section reduces noise
crosstalk and improves the integrity of the output signal.
When using separate power supplies, connect each
power supply across the DVDD and DGND PC board
pads (digital), across the VDD_CK and GND_CK PC
board pads (digital clock), and across the AVDD and
AGND PC board pads (analog) on the EV kit.
LVDS Input Data
The MAX5888 EV kit provides two 0.1in 2 x 20 header
connectors (J1 and J2) to interface a 16-bit LVDS pattern generator to the EV kit. The header data pins are
labeled on the board with the appropriate data bit designation. Use the labels on the EV kit to match the data
bits from the LVDS pattern generator to the corresponding data pins on J1 and J2. The positive rail of a
bit is labeled BxP (positive) and the complementary rail
is labeled BxN (negative) where x is the bit number.
Clock Signal
The MAX5888 requires a differential clock input signal
with minimal jitter. The EV kit circuit provides singleended to differential conversion circuitry. The user must
supply a single-ended clock signal at the CLK SMA
connector.
The clock signal can be either a sine wave or a square
wave. For a sine wave, 2VP-P (10dBm) amplitude is
recommended and for a square wave greater than a
0.5VP-P signal is recommended.
Reference Voltage Options
The MAX5888 requires a reference voltage to set the
full-scale analog signal voltage output. The DAC contains an internal stable on-chip bandgap reference of
1.2V that can be used by decoupling the REFIO pin.
The internal reference can be overdriven by an external
reference to enhance accuracy and drift performance
or for gain control.
The MAX5888 EV kit features three ways to provide a
reference voltage to the DAC: internal, on-board external, and user-supplied external reference. Verify that no
shunt is connected across jumper JU1 to use the internal reference. The reference voltage can be measured
at the VREF pad on the EV kit. The EV kit circuit is
designed with an on-board 1.25V temperature-stable
external voltage reference source U2 (MAX6161) that
can be used to overdrive the internal reference provided by the MAX5888. Install shunts across jumpers JU1
and JU2 to use the on-board external reference. The
user can also supply an external voltage reference in
the range of 0.125V to 1.25V by connecting a voltage
source to the VREF pad and removing the shunts
across jumpers JU1 and JU2. See Table 1 to configure
the shunts across jumpers JU1 and JU2 and select the
source of the reference voltage.
Full-Scale Output Current
The MAX5888 requires an external resistor to set the
full-scale output current. The MAX5888 EV kit full-scale
current is set to 20mA with resistor R7. Replace resistor
R7 to adjust the full-scale output current. Refer to the
Reference Architecture and Operation section in the
MAX5888 data sheet to select different values for R7.
Differential Output
The MAX5888 complementary current outputs are terminated into differential 50Ω resistance to generate voltage
signals with amplitudes of 1VP-P differential. The positive
and negative rails of the differential signal can be sampled at the OUT+ and OUT- probe connectors. The differential signal is converted into a 50Ω singled-ended
signal with balun transformer T2 and can be sampled at
the OUT SMA connector. A shunt on jumper JU4 connects the center tap of transformer T2 to AGND, thus
enhancing the dynamic performance of the DAC. The
single-ended output signal after the transformer generates a -3dBm full-scale output power when terminated
into 50Ω. A shunt on jumper JU4 should always be
installed for optimum dynamic performance.
Table 1. Reference Voltage Selection
JU1 AND JU2
SHUNT POSITIONS
Installed
VOLTAGE REFERENCE MODE
External 1.25V reference (U2)
connected to REFIO pin
Not installed
MAX5888 DAC internal 1.2V bandgap
reference
Not installed
User-supplied voltage reference at the
VREF pad (0.125V to 1.25V)
_______________________________________________________________________________________
3
Evaluates: MAX5886/MAX5887/MAX5888
three separate 3.3V power supplies by dividing the circuit grounds into digital, analog, and digital clock
ground planes that improve dynamic performance. The
three ground planes are connected together on the
back of the PC board.
Evaluates: MAX5886/MAX5887/MAX5888
MAX5888 Evaluation Kit
Power-Down
The MAX5888 can be powered down or powered up by
configuring jumper JU3. In power-down mode, the total
power dissipation of the DAC is reduced to less than
1mW. See Table 2 for jumper JU3 configuration.
Table 2. Jumper JU3 (Power-Down)
SHUNT
FUNCTION
Installed
Power-down mode
Not installed
Normal operation
Segment Shuffling
The segment-shuffling function on the MAX5888
improves the high-frequency spurious-free dynamic
range (SFDR) at the cost of a slight increase in the
DAC’s noise floor. The MAX5888 EV kit provides jumper
JU5, which allows the user to enable or disable this function. See Table 3 to configure jumper JU5.
Table 3. Segment-Shuffling Mode
(Jumper JU5)
SHUNT
Evaluating the MAX5887 or MAX5886
The MAX5888 EV kit can be used to evaluate the
MAX5887 or MAX5886 DACs. The MAX5887 is a 14-bit
DAC and the MAX5886 is a 12-bit DAC. Except for the
input pins, these DACs are pin-for-pin compatible with
the MAX5888. Replace the MAX5888 (U1) with the
MAX5887 or the MAX5886 and refer to the respective
data sheet to compare the difference in input pins and
how to modify the connections between the pattern
generator and the EV kit input connectors.
Installed
Not installed
SEL0 PIN
SEGMENT-SHUFFLING
MODE
Connected to
DVDD
Enabled
Connected to
DGND with
internal pulldown
resistor
Disabled
Board Layout
The MAX5888 EV kit is a four-layer board design optimized for high-speed signals. All high-speed signal
lines are routed through 50Ω impedance-matched
transmission lines. The length of these 50Ω transmission lines is matched to within 40 mils (1mm) to minimize layout-dependent data skew. The board layout
separates the analog, digital, and digital clock sections
of the circuit for optimum performance.
4
_______________________________________________________________________________________
_______________________________________________________________________________________
CLK
1
GND_CK
TP2 2
1
GND_CK
3
J2-37
J2-35
J2-33
J2-4
J2-6
J2-8
J2-5
J2-3
J2-1
J2-36
J2-38
J2-40
R10
24.9Ω
1%
AVDD
C14
0.1µF
JU2
U2
GND_CK
GND_CK
DVDD
OUT
N.C.
N.C.
1 C24
10µF
2 10V
5
6
7
8
GND_CK
9
8
7
6
5
4
3
2
1
C27
1.0µF
JU1
17
15
16
14
13
12
11
10
18
AVDD
PD
CLKGND
VCLK
CLKN
CLKP
CLKGND
VCLK
DVDD
DGND
B0N
B0P
B1N
B1P
B2N
B2P
B3N
B3P
C25
1.0µF
VDD_CK
TP4
JU3
C8
0.1µF
VDD_CK
GND_CK
C9
0.1µF
VDD_CK
GND
MAX6161
GND
N.C.
IN
N.C.
1 C23
47µF
2 6.3V
4
3
2
1
C28
OPEN
R13
0Ω
R12
0Ω
L2
GND_CK
C13
0.1µF
C12
0.1µF
GND_CK
C16
OPEN
C22
1.0µF
VDD_CK
1 C21
10µF
2 10V
R11
4
GND_CK 24.9Ω
1%
T3
J2-7
J2-34
6
J2-9
J2-32
J2-30 J2-11
J2-28 J2-13
J2-26 J2-15
J2-24 J2-17
J2-22 J2-19
J2-20 J2-21
J2-18 J2-23
J2-16 J2-25
J2-14 J2-27
J2-12 J2-29
J2-10 J2-31
J2-39
J2-2
J2
1 C20
47µF
2 6.3V
VREF
19
C26
10µF
10V
C7
0.1µF
L4
VREF
C2
0.1µF
20
VREF
21
R7
2kΩ
1%
22
23
B4N
AVDD
68
B4P
AGND
67
B5N
REFIO
66
B5P
FSADJ
DGND
DVDD
TP1
DVDD
24
AVDD
JU4
OUT-
C10
0.1µF
J1-40
B6N
DACREF
65
B6P
N.C.
63
J1-1
U1
C15
0.1µF
1
1
6
C1
OPEN
6
R3
100Ω
0.1%
26
5
2
T1
TP3
28
2
OUT
29
C5
0.1µF
R8
SHORT
R4
100Ω
0.1%
R2
100Ω
0.1%
T2 1
3
4
3
4
R6
OPEN
R5
100Ω
1%
27
MAX5888
R1
100Ω
0.1%
R9
SHORT
C6
0.1µF
25
DGND
AVDD
62
DVDD
AGND
64
J1-38
IOUTN
L1
60
J1-3
OUT+
30
AVDD
GND_CK
C4
0.1µF
31
C3
0.1µF
32
33
AVDD
34
B7N
61
J1-36
DGND
J1-34
J1-7
J1-5
B7P
AGND
59
J1-32
IOUTP
58
J1-9
57
B8N
AVDD
56
B8P
AVDD
55
B9N
AGND
54
B9P
AVDD
53
B10N
AGND
N.C.
N.C.
N.C.
N.C.
SEL0
DGND
DVDD
B15P
B15N
B14P
B14N
B13P
B13N
B12P
B12N
B11P
B11N
52
B10P
N.C.
C11
0.1µF
C19
1.0µF
35
36
37
38
39
41
40
42
43
44
45
46
47
48
49
50
51
JU6
JU5
DVDD
C18
10µF
10V
2
1
AVDD
DVDD
DVDD
J1
C17
47µF
6.3V
L3
J1-39
J1-37
J1-35
J1-33
2
1
J1-2
J1-4
J1-6
J1-8
J1-31 J1-10
J1-29 J1-12
J1-27 J1-14
J1-25 J1-16
J1-23 J1-18
J1-21 J1-20
J1-19 J1-22
J1-17 J1-24
J1-15 J1-26
J1-13 J1-28
J1-11 J1-30
AGND
AVDD
Evaluates: MAX5886/MAX5887/MAX5888
DVDD
MAX5888 Evaluation Kit
Figure 1. MAX5888 EV Kit Schematic
5
Evaluates: MAX5886/MAX5887/MAX5888
MAX5888 Evaluation Kit
Figure 2. MAX5888 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX5888 EV Kit PC Board Layout—Component Side
Figure 4. MAX5888 EV Kit PC Board Layout—Ground Planes
Figure 5. MAX5888 EV Kit PC Board Layout—Power Planes
6
_______________________________________________________________________________________
MAX5888 Evaluation Kit
Figure 7. MAX5888 EV Kit Component Placement Guide—
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Evaluates: MAX5886/MAX5887/MAX5888
Figure 6. MAX5888 EV Kit PC Board Layout—Solder Side