Linear Technology DC1298 Quick Start Manual

DESCRIPTION
Demonstration circuit 1298 is an evaluation board featur-
ing Linear Technology Corporation's LTM9002 14-bit
Dual Receiver Subsystem. DC1298 demonstrates good
circuit layout techniques and recommended external cir-
cuitry for optimal system performance.
DC1298 comes with Linear Technology's 14-bit
LTM9002 amplifier/ADC subsystem installed. The board
includes a wideband input transformer (for evaluation
with a single-ended RF signal generator) and output
CMOS buffers. DC1298 plugs into the DC890 Data Ac-
QUICK START PROCEDURE
Validating the performance of the LTM9002 is simple
with DC1298, and requires only two input sources, a
clock source, a computer, and a lab power supply. Refer
to Figure 1 for proper board evaluation equipment setup
and follow the procedure below:
1. Connect the power supply as shown in Figure 1.
There is an on-board low-noise voltage regulator
that provide the four supply voltages for the
DC1298. The entire board and all components
share a common ground. The power supply should
be a low-noise lab power supply capable of supply-
ing at least 1 Amp.
2. Provide an encode clock to the ADC via SMA con-
nector J1. Use a low-phase-noise clock source
such as a filtered RF signal generator or a high-
quality clock oscillator. Obtain DC1216 for a low-
phase-noise ADC clock source that can plug di-
rectly into DC1298.
NOTE. Similar to having a noisy input, a high-jitter (phase noise) encode
clock will degrade the signal-to-noise ratio (SNR) of the system.
Downloaded from Elcodis.com electronic components distributor
DEMO CIRCUIT DC1298
LTM9002 14 bit Dual Channel
IF/Baseband Receiver Subsystem
quisition demo board and the output can be easily ana-
lyzed with Linear Technology's PScope data processing
software, which is available for no charge on our website
at http://www.linear.com.
Design files for this circuit board are available. Call
the LTC factory.
L , LTC, LTM, LT, Burst Mode, OPTI-LOOP, Over-The-Top and PolyPhase are registered
trademarks of Linear Technology Corporation. Adaptive Power, C-Load, DirectSense, Easy
Drive, FilterCAD, Hot Swap, LinearView, µModule, Micropower SwitcherCAD, Multimode
Dimming, No Latency ∆Σ, No Latency Delta-Sigma, No R SENSE , Operational Filter, PanelPro-
tect, PowerPath, PowerSOT, SmartStart, SoftSpan, Stage Shedding, SwitcherCAD, ThinSOT,
UltraFast and VLDO are trademarks of Linear Technology Corporation. Other product names
may be trademarks of the companies that manufacture the products.
Table 1: DC1298 Connectors and Jumpers
REFERENCE
J1 (+INA)
J2 (-INA)
J3 (+INB)
J4 (-INB)
J6 (CLKIN)
E1 (EXT REF A)
E2 (EXT REF B)
JP1 (DAC I/O)
JP2 (SENSE)
DC1298
QUICK START GUIDE
FUNCTION
Board IF Signal Input, channel A single-ended.
Impedance-matched to 50Ω for use with lab
signal generators.
Board IF Signal Input, channel A. Normally not
used, but can be configured as the negative
side of a differential input.
Board IF Signal Input, channel B. Normally not
used, but can be configured as the negative
side of a differential input.
Board IF Signal Input, channel B single-ended.
Impedance-matched to 50Ω for use with lab
signal generators.
Board Clock Input. Impedance-matched to
50Ω. Drive with a low-phase-noise clock oscil-
lator or filtered sine wave signal source.
Reference input to adjust the full-scale range of
the FT107, channel A. Connects to the SENSE
pin; by default, tied to VDD for internal refer-
ence.
Reference input to adjust the full-scale range of
the FT107, channel B. Connects to the SENSE
pin; by default, tied to VDD for internal refer-
ence.
DAC serial interface.
ADC sense voltages, default is VDD.
1