UmVXO
UmVXO is a daughterboard for UmTRX SDR transceivers which allows you to change its reference clock, without soldering and with almost no impact on the UmTRX overall dimensions.
UmVXO features high quality temperature-compensated voltage-controlled crystal oscillator (TCVCXO) with the same parameters as the onboard UmTRX TCVCXO, but with a different frequency.
You can also synchronize clock and 1PPS signals of up to 4 UmTRXs with the single UmVXO to achieve up to 8×8 MIMO.
Hardware Features
- Female plug for UmTRX v2.2 or v2.3.1 AUX RF connector
- Onboard TCVCXO 30.72 MHz clock oscillator (20, 25, 26 and 40 MHz upon request), tunable from UmTRX (GPSDO function)
- Four reference clock signal distribution outputs
- 1PPS synchronization signal distribution outputs
- Ultra low noise LDO DC regulator for better possible specifications
Specification
Parameter | Value |
|---|---|
| Physical dimensions | 29 mm x 17 mm x 7 mm |
| Power Supply voltage range | +5.5V typical, +4 to +6.5 V max |
| Power Supply current, w/o CLK loads | < 50 mA |
| Power Supply current, all CLK outputs loaded | < 200 mA |
| DC regulator noise | RMS - 9 uV |
| Power Supply supression ratio (PSSR) | > 40 dB (10 Hz to 4 GHz) |
| Output frequency | 30.72 MHz (20, 25, 26 and 40 MHz upon request) |
| Frequency stability | ±280 ppb (±0.28 ppm) at -40°C to +85°C |
| Tuning DAC resolution | 12 bit, 0 to 3.3V (~0.8 mV LSB) |
| TCVCXO Aging (20 years @+25°C) | ±3 ppm typical, ±4.6 ppm max |
| TCVCXO frequency tuning range | ±10 ppm typical, ±7 ppm min |
| Maximum Phase Noise (30.72 MHz) at 10Hz carrier offset | -85 dBc/Hz |
| Maximum Phase Noise (30.72 MHz) at 1kHz carrier offset | -130 dBc/Hz |
| Maximum Phase Noise (30.72 MHz) at 10kHz carrier offset | -135 dBc/Hz |
| Maximum Phase Noise (30.72 MHz) at 100kHz carrier offset | -140 dBc/Hz |
| RMS Jitter (12kHz to 20MHz BW) | ~ 1 pS |
| Logic level of outputs | LVCMOS 3.3V |
