S
SMDM-70-TTL
D
ITHERING
M
ODULES
S
PECIFICATIONS
Analog Signal Path:
Pass Band Frequency: 60-80 MHz
Insertion Loss: 1.0dB
max
Impedance: 50 ohm
VSWR: 1.4:1
max
LO Rejection: 55dB
min
@
f>450MHz
Noise Output:
Frequency: 200 kHz - 2.0 MHz
Noise Flatness: 2 dB P-P
max
Noise power: -40 dBm
min
,
-34 dBm
max
Low pass noise rejection:
-150 dBm/Hz
@
5.0 MHz
-Total noise rejection @ f>15 MHz
SMDM-70-TTL O
UTPUT
C
HARACTERISTICS
Micronetics’ dithering module is designed as an easy way to eliminate spurs
caused by quantization errors in high speed A/D converters. This module
feature a patent pending technology to efficiently combine low pass filtered
noise with the analog signal, resulting in low signal insertion loss and low
power consumption. The module is designed for 70 MHz analog signals
(other frequencies upon request)
and eliminates the need to design special
circuitry for the noise biasing, amplification and filtering as well as combin-
ing the signal to the out of band noise.
D
ESCRIPTION
The dithering module is a two port device with an analog signal input and a
signal + noise output. The complete noise generating circuitry is contained
within this module. The dithering module is specified by two paths, one
being the analog signal path and the other being the noise output of the
combined signal + noise path. The module also features built in LO rejec-
tion filtering.
General Specs:
Operating Temp: -40 to +85 degC
Storage Temp: -55 to +100 degC
Supply: 15V + 0.5V @ 75 mA
max
Control Logic TTL:
Logic 1: Noise On
(internal pull up)
2.8 - 5.5 V
Logic 0: Noise Off
0 - 0.75 V
How to order:
SMDM-70-TTL
Dithering module, suface mount
SMDM-70-TTL-EVAL
coaxial connectorizd, populated
evaluation board
C
OMMON
N
OISE
C
ONVERSIONS
• N = N
o
+ 10*LOG (BW)
• N
o
= 20*LOG (µV
RMS
/Hz)
• N = 20*LOG (V
RMS
) - 10*LOG (R) + 30 dB
where:
BW = bandwidth in hertz
R = impedance in ohms
N = power in dBm
No = power spectral density in dBm/Hz
26 HAMPSHIRE DRIVE / HUDSON, NH 03051 / TEL: 603-883-2900 / FAX: 603-882-8987 / NOISESALES@MICRONETICS.COM
WWW.MICRONETICS.COM
MICRONETICS [ MICRONETICS, INC. ]
