Additional Information - Linear Technology DC1398 Quick Start Manual

LTM9001
NOTE. Even a high-quality signal
synthesizer will still have noise and
harmonics that should be attenuated
with a low-pass or band-pass filter.
For good-quality high order filters,
see TTE, Lark Engineering, or
equivalent.
Signal
Generator
HP 8644B
or equiv.
RF Signal Generator
(HP 8644B) or other
low phase noise
clock source (e.g. DC1216)

ADDITIONAL INFORMATION

Although the DC1398 demo board is ready to use on de-
livery, it has additional flexibility built in for various types
of input networks. Below is some information about con-
figuring DC1398 to meet the specific needs of your eval-
uation.
APPLYING INPUT SIGNALS
The input network consists of various components de-
signed to allow either single-ended or differential inputs,
AC-coupled or DC-coupled. Table 2 shows some possi-
ble input configurations, and which components to in-
stall. LTM9001 is designed for excellent performance
with both single-ended and differential input drive, with
little difference in distortion performance. When using
DC-coupled inputs, the inputs to DC1398 need to be lev-
2
Power Supply
(3.8V-6V @ 1.0A)
BPF
BPF
Proper Evaluation Equipment Setup
Figure 1.
el-shifted to within the input common-mode limits in the
datasheet.
Table 2: DC1398 Input Configuration Guide
CONFIGURATION COMPONENTS NECESSARY
Single-Ended Input No change. Transformer T1 acts as a balun for
differential drive.
AC-Coupled
(Default Setup)
Single-Ended Input Remove T1, replace with 0Ω jumpers. May need
to install impedance-matching resistor at R4
No Transformer
or R2/R6.
AC-Coupled
Single-Ended Input Same as above. Change C1 and C8 to 0Ω jump-
ers. Inputs must be within the common-
No Transformer
mode voltage limits of LTM9001.
DC-Coupled
Differential Inputs Remove R7 and install R5. T1 and C1/C8 can be
replaced with 0Ω for DC coupling.
To DC890