an1190

ISL5x27EVAL1 User’s Manual
®
Application Note
April 7, 2005
AN1190.0
Description
Getting Started
The ISL5x27EVAL1 evaluation board provides a quick and
easy method for evaluating the ISL5627, ISL5727, ISL5827,
ISL5927 (8-, 10-, 12-, or 14-bit), 260MSPS high-speed dual
DACs. The board is configured to route the DAC differential
output currents into a transformer balanced load to form an
output voltage. The amount of current out of the DAC is
determined by an external resistor and either an internal or
external reference voltage. The CMOS digital inputs have
optional external termination resistors. The evaluation board
includes a ribbon cable digital interface.
See Figure 1. A summary of the external supplies,
equipment, and signal sources needed to operate the board
is given below:
Features
• 260MSPS 8-, 10-, 12-, or 14-bit CMOS Dual DAC
• Transformer-Coupled or Single-Ended SMA Outputs
Ordering Information
TEMP.
RANGE NUMBER OF
(°C)
BITS
PART
NUMBER
CLOCK
SPEED
ISL5627EVAL1
25
2x8
260MHz
ISL5727EVAL1
25
2x10
260MHz
ISL5827EVAL1
25
2x12
260MHz
ISL5927EVAL1
25
2x14
260MHz
1. +3.3V supply for ISL5x27 DAC.
2. 3V LVCMOS compatible pattern source.
3. Low jitter clock source (<10ps preferable).
4. Spectrum Analyzer or Oscilloscope for viewing the output
of the converter.
Connect the evaluation board to the power supply(s).
Connect the data output from the pattern generator to the
evaluation board 2x20 pin connectors J1 and/or J3. Connect
the clock source to the evaluation board, either through pin
19 of connectors J1 or J3 or via the provided SMA (J2).
Using a coaxial cable with the proper SMA connector, attach
the output of one side of the dual converter, IOUT (J12) or
QOUT (J9), to the measurement equipment that will be
evaluating the converter’s performance. Make sure that the
evaluation board jumpers are in their proper placement (see
jumper info).
Turn the power supply on. Turn the pattern and clock on and
measure the DAC performance at the analog output SMA
(J9 or J12).
Functional Block Diagram
QOUTA
SMA
2x20 PIN HEADER
2x20 PIN HEADER
8-14 BITS
8-14 BITS
DUAL
DAC
QOUT
SMA
XFMR
IOUT
SMA
QOUTB
SMA
IOUTB
SMA
CLOCK
IOUTA
SMA
CLKIN
SMA
XFMR
DVDD PLANE
DGND PLANE
AVDD PLANE
CLKOUT
SMA
AGND PLANE
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright Intersil Americas Inc. 2005. All Rights Reserved
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Application Note 1190
GORE QUIETZONETM CABLES
PATTERN GENERATOR
ISL5x27 EVALUATION BOARD
2x20 PIN HEADER
2x20 PIN HEADER
8-14 BITS
1/2 ISL5x27
DAC
8-14 BITS
SPECTRUM ANALYZER
1/2 ISL5x27
CLOCK
OPTIONAL
DIRECT CLK
CABLE
50Ω
SMA
CABLE
DAC
+3.3V
POWER
SUPPLY
FIGURE 1. INTERSIL ISL5x27 EVALUATION SYSTEM SETUP BLOCK DIAGRAM
Board Options
Clock
Jumpers (Default State)
The clock circuitry on the ISL5x27eval1 is designed for a
couple of options to be available. One option allows a high
quality clock signal to be connected directly to J2. The
combination of jumpers and resistors surrounding J2 allows
the user to create a 50Ω power splitter so the same clock
can be fed off the board (J22) to clock the digital pattern
source without reflections causing degradations in DAC
performance.
J19 - Selects DAC Sleep Mode (OPEN)
J21 -Selects External Reference (OPEN)
J20 - Selects Internal Reference (SHORT)
J17, J5 - Selects IOUTA, QOUTA (OPEN)
J15, J4 - Selects IOUTB, QOUTB (OPEN)
J8, J14 - Grounds the Transformer Output (SHORT)
J23-J27 - Selects Clock Path and Termination
Output Transformer
T1, 4 - T1-1T (case style Mini-Circuits KK81)
T2, 3 - ADT1-1WT (case style Mini-Circuits CD542)
Clock Input
2x20 Pin Headers J1 or J3 (pin 19)
SMA - J2
Clock Output
SMA - J22
To use the 50Ω power splitter connect the clock source to J2.
Make sure that R16, R31, and R32 are ~17Ω. Populate
jumpers J24 and J25. Do not populate J23, J26, or J27. With
C20, R47, and R48 populated, the clock will be biased at the
DAC clock input, so the clock source does not have to be DC
biased. If using J2 as the clock input but not using J22 to
clock an external device, populate jumper J27 so the
impedance of the power splitter is maintained.
Another option is to bring the clock on the board via the
ribbon cables. Choose pin 19 of J1 or J3, but not both.
Populate the necessary jumper to connect pin 19 to the DAC
clock input (J23 if via J1 or J26 if via J3). Do not populate
J24 or J25 (unless 50Ω termination is desired).
Digital Inputs
RSET
Fixed Resistor - R91 (1.91kΩ = 20mA full scale output)
Potentiometer - R90
Power SupplySplit AVDD and DVDD
The digital inputs are expecting 3V CMOS levels in offset
binary format. The board is shipped without termination
resistors so that most systems can drive the load. The board
is configured so the user can populate 50Ω termination
resistors if required. Consult the datasheet for the DAC for
min/max amplitude requirements for the clock and data.
Single VDD (by installing R63)
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Application Note 1190
Analog Outputs
The transformer configuration is such that it expects to see a
50Ω load at the end of an RF cable. If the user wishes to
evaluate the single-ended performance of the DAC, J4/J5
and/or J15/J17 will need to be populated, R73, 74, 79, and
80 should be populated with 50Ω resistors, and R69, 71, 76,
and 77 should be removed to eliminate the transformer and
differential resistor from the circuit. Other loading can be
considered so long as the combination of the output current
and output resistance does not violate the output voltage
compliance range.
Board Schematics/Layout/BOM
The schematics, board plots, and bill of materials can be
downloaded from the Intersil web site. Search on the DAC
part number using the Part Search.
ISL5x27 + ISL5217
The ISL5x27 evaluation board is designed to interface
directly to an ISL5217 evaluation board. The ISL5217 is an
Intersil 104MSPS Digital Up Converter (DUC). The ISL5217
can be used to generate 1–4 narrowband carriers or 1–2
wideband carriers. Consult the ISL5217 documentation for
detailed information on using the ISL5217EVAL.
Using short ribbon cables, connect J3 and/or J4 on the
ISL5217EVAL (DUC) to J1 and/or J3 on the ISL5x27EVAL1
(DAC). These ribbon cables connect the digital outputs of
the ISL5217 to the digital inputs of the ISL5927.
To provide a common clock signal for the boards, remove
oscillator U6 from the DUC board and connect an RF cable
from J11 of the DUC board to J22 of the DAC board.
(Sometimes the length of the cable has to be adjusted to
achieve adequate setup and hold times between DATA and
CLK.) For the DAC board, jumpers J23, J26, and J27 are not
populated. The clock source should be connected to J2 on
the DAC board by an RF cable. On the ISL5217EVAL, verify
the jumper from JP5 pin 2 to JP5 pin 3 is installed. Also
install a jumper from JP5 pin 1 to JP6 pin 1 to provide 50Ω
clock signal termination. See Figure 2 for a block diagram of
the two boards connected. Consult the schematic for the
ISL5217EVAL for more information regarding the DUC.
RF CABLE
J11
CLOCK IN (104MSPS MAX)
RIBBON CABLES
2x20 PIN HEADER
2x20 PIN HEADER
2x25 PIN HEADER
2x25 PIN HEADER
J22
ISL5217
4CH DIGITAL
UP CONVERTER
50Ω
SMA
CABLE
J2
14 BITS
1/2 ISL5927
DAC
TO SPECTRUM
ANALYZER
14 BITS
CLOCK
1/2 ISL5927
DAC
ISL5x27 DAC EVALUATION BOARD
+3.3V (<0.25A)
+5V (<2A)
ISL5217 DUC EVALUATION BOARD
POWER
SUPPLY
POWER
SUPPLY
FIGURE 2. INTERSIL ISL5927 + ISL5217 SETUP BLOCK DIAGRAM
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Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
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