Novatech Instruments 408A - Specifications

2
408A Manual
1.0
DESCRIPTION
1.1 The Model 408A is a 100MHz Quadrature
D
irect
D
igital
S
ynthesizer (DDS) in a small table
top case with RS232 serial control. The 408A pro-
vides both Cosine(I), Sine(Q) and 3.3V ACMOS
output signals, which can be set from 100Hz to
100MHz in 1µHz steps when using the internal
VCTCXO (voltage controlled temperature compen-
sated crystal oscillator) clock.
1.2 The 408A can also be used with an External
Clock input. An on-board programmable frequency
multiplier generates the master clock allowing user
configured frequency ranges. The multiplier can be
disabled for direct inputs up to 300MHz for opti-
mum phase noise performance. When used with an
external clock, multiple 408A are phase synchro-
nous.
2.0
SPECIFICATIONS
2.1 OUTPUTS
TYPES: Sine, Cosine and ACMOS/TTL Simulta-
neously.
IMPEDANCE: 50Ω.
FREQUENCY: 100Hz to 100MHz in 1µHz steps,
using Internal Clock. (1x10
-13
resolution @10MHz)
2.2 SINE/COSINE AMPLITUDE
AMPLITUDE: Approximately 0.5Vrms (+7dBm)
into 50Ω. Programmable from 0/4096 to 4095/4096
of Full Scale (12 Bits).
FLATNESS:
±
3dB from 100kHz to 100MHz refer-
enced to amplitude at 30MHz, stable to
±
1dB from
18-28
o
C.
2.3 ACMOS/TTL AMPLITUDE
V
OL
<0.5V, V
OH
>2.5V into a 15pF load, series ter-
minated. Rise and Fall Times <5ns. Duty Factor: 45-
55%. 50Ω output impedance. Use series or capaci-
tively-coupled parallel termination.
2.4 ACCURACY AND STABILITY
Accurate to <
±
1.5ppm at 10-40
o
C. Stable to an addi-
tional ±2ppm per year, 18-28
o
C.
NOVATECH INSTRUMENTS
2.5 EXTERNAL CLOCK INPUT
LEVEL: 0.35-2.5Vrms Sine or Square Wave can be
applied to the EXT CLK Input BNC. 50Ω.
FREQUENCY: Input range of 5MHz to 75MHz.
Programmable frequency multiplier (4x to 20x) on
board. Multiplier can be bypassed for direct input to
300MHz. An external filter may be required for
optimum performance.
2.6
SPECTRAL PURITY
(Typ. 50Ω load, int clk)
Phase Noise: <-140dBc, 10kHz offset, 5MHz out.
Spurious: <-70dBc below 10MHz (200MHz span)
<-65dBc below 40MHz
<-60dBc below 60MHz
<-50dBc below 100MHz
Harmonic: <-70dBc below 1MHz
<-60dBc below 10MHz
<-50dBc below 20MHz
<-40dBc below 50MHz
<-35dBc below 100MHz
2.7 CONTROL
Output Frequency and phase (14-bits) are controlled
by an RS232 serial port at 19.2kBaud. RS232 con-
trol allows non-volatile storage of settings.
2.8 SWITCHING TIME
RS232 control depends upon host speed and com-
mands sent, typically <10ms for a new frequency.
2.9
POWER REQUIREMENTS
+4.5 to +5.5VDC @<1.25A. Line voltage adapter
provided. (Units with serial numbers before N06001
used +12V nominal).
2.10
SIZE
Table top case: 40mm H, 106mm W, 172mm L,
excluding connectors.
2.11 CONNECTORS
Front panel BNCs for SINE(Q), COSINE(I) and
ACMOS/TTL. Rear panel BNC for EXT CLK IN.
Power: 2.5mm center positive. DE9F for serial.