High performance 8-channel Pulse and Frequency distribution amplifier
This 1U 19" rack project houses two boards, one 8-channel logic-pulse distribution amplifier (pda) board (i.e., for 1 pulse-per-second signals) and one 8-channel frequency distribution amplifier (fda) for typically 5 or 10 MHz sine-wave signals. The boards can be built with either BNC or SMA connectors. DC power to the boards is supplied by two +9VDC "brick" powersupplies via a 230VAC IEC-connector on the back panel.
- latest release "FDA 2017.03", board revision 3 on 2018-02-15.
- 2-sided PCB, 170 mm x 70 mm
- Input stage LMH6702 1.7 GHz CFA op-amp
- Output stages LMH6609 900 MHz VFA op-amp
- +6V and -6V low-noise DC rails provided by LT1963A (1.5A, 40 uVRMS noise) and LT3015 (-1.5A, 60 uVRMS noise) low-noise regulators.
- residual phase-noise below -160 dBc/Hz @ 1 kHz offset from a 10 MHz carrier.
- ToDo: level detector? (logic-pin or LED to indicate presence of signal)
- ToDo: LED indicator for input signal
- ToDo: monitoring interface? (arduino or similar, Ethernet?)
- ToDo: multiple inputs?
- latest release "PDA 2017.04", board revision 3 on 2018-02-15
- 2-sided PCB, 170 mm x 70 mm
- +3V3 DC-rail from LT1963A
- Input to LT1711 comparator
- 1.0V trigger level, from LT1790 voltage reference
- fan-out and outputs from IDT5PB1108
- LTC6993 timer drives 200ms "BLINK" pulse to front panel LED
- trimmer-caps on each output allows tuning the output-to-output delay skew.
- typical output-skew 200 ps before tuning, <20 ps after tuning.
- drives 3.3V pulse into 1 MOhm (not recommended!) and ca 2.7V pulse into a 50 Ohm load.
- <700 ps 10%-to-90% rise-time into 50R load, measured with 4 GHz oscilloscope.
- Two boards fit side-by-side an a 1U high 19" rack enclosure.
- 16 mm connector-to-connector distance, either SMA or BNC
- 150 mm deep enclosure (can be reduced, depending on powersupplies)
- two front panel indicator LEDs per board
- AC connector on back panel
- passively cooled, no fan.
- VTT MIKES UTC-laboratory, Finland
- Metsähovi Geodetic Research Station, Finland
- Anders Wallin's blog on Electronics
Design and general questions
- Anders Wallin (anders.e.e.wallin "at" gmail.com)
- Aivon LTD , Finland
- ? Sync Technology , (Beijing) China ?
|01-2015||First ideas for making the distribution amplifiers|
|18-12-2015||First tests on Pulse distribution amplifier prototypes|
|27-12-2015||Frequency Distribution Amplifier, v2 simulations made|
|30-01-2017||Frequency Distribution Amplifier measurements made|
|12-08-2017||Project started on ohwr|
|18-08-2017||5 prototypes built. S/N 005 tested|
|29-08-2017||Metsähovi connected to the official time of Finland with the distribution amplifier|
|21-10-2017||Design files published on ohwr.org|
|03-01-2018||Enclosure Design notes and CAD files published|
|15-02-2018||Aivon LTD announced commercial availability of 1:8 PDA/FDA|
|04-01-2019||Sync Technology, plans for commercial availability of 1:8 PDA/FDA|
|2020-05-29||160mm wide FDA|
|2020-10||Aivon produces S/N 30 of the FDA/PDA|