Features
Fixed Bit Rates Up to 30 Mbps, All Codes!
· Occupies Single Daughter Card Location
· Up to Four Bit Syncs Per VME Slot
· Selectable IRIG PCM Formats
· Selectable Loop Bandwidths
· Selectable Input Impedance of 50, 75, and 10K ohms
· BER Performance Better than 1.0 dB
· Output Status LED Drivers
Introduction
The PCM Bit Synchronizer card is a multifeatured, digitally controlled bit synchronizer that provides state-of-the-art BER performance. The QSNC bit sync excels in harsh noise conditions with signal-to-noise capabilities superior to every other board and box level unit in its class.
The QSNC module represents a breakthrough in high-speed digital bit synchronizers. Its patented phase-lock loop and tracking features allow the QSNC bit sync to attain the performance levels of box-level bit synchronizers costing two to three times as much with equal performance.
Occupying a single VME quadraplex daughter card position, the QSNC bit sync provides complete front-end flexibility to the system integrator. Full-time selectability includes impedance and polarity, while programmability at the time of order includes input code type, bit rate, and loop bandwidth.
The QSNC bit sync is used in PCM applications where noise-reliable solutions are required for noise perturbation problems, and where highly compact PCM bit synchronization hardware is essential. Our bit sync design, which has received a U.S. patent, uses the most advanced, low-power, high-reliability circuit components available on the market today. The automatic self-calibration of internal filters provides built-in adjustments over the lifetime of the board to offset the inevitable problems of component aging.
Input Signal |
Codes |
NRZ-L/M/S, BIØ-L/M/S, DBIØ-M/S, DM-M/S, MDM-M/S, RZ |
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Level |
500 mV to 10 volts peak-to-peak |
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Derandomizer |
5 lengths; 9, 11, 15, 20, and 23 |
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Impedance |
50 ohms, 75 ohms (default), and 10K ohms (hardware programmable) |
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Sources & Type |
One external data input, single-ended or differential (RS-422 levels) |
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Polarity |
Normal or inverted (hardware programmable) |
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Loop Bandwidth |
0.05% to 5% (programmable at time of ordering – see ordering notes) |
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Operating Range |
10 bps to 30 Mbps |
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(NRZ codes) |
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Operating Range |
10 bps to 30 Mbps |
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(All other codes) |
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Performance |
Bit Error Rate |
Within 1.0 dB of theoretical curve up to maximum data rate |
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Acquisition Range |
Up to +/- 5% of programmed data rate (limited by configuration) |
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Acquisition Time |
Within 50 bits, average, random data within 0.5% deviation from the programmed data rate, Eb/No = 15 dB |
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Sync Maintenance |
Retains sync with NRZ codes at Eb/No = 3 dB with 128-bit transition gaps occurring every 512 bits with random data |
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Bit Slippage |
Maintains phase with BIØ codes at Eb/No = 12 dB with over 2000 continuous 1's or 0's, at Eb/No=0 db with random data (NRZ & BIØ) |
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Tracking Range |
Up to +/- 20% of programmed data rate (limited by configuration) |
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Baseline Variation |
No degradation beyond 1 dB theoretical performance curve with superimposed wave form equal to 100% of the peak-to-peak signal input at 0.1% of the bit rate, BIØ codes |
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DC Offset |
100% of input signal level up to +/-10 Volts |
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Output |
NRZ-L Data |
TTL compatible into 50? and RS-422 Differential |
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Clock |
Selectable 0° and 180° phase; TTL or RS-422 output |
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Electrical and |
Form Factor |
Single-slot, Quadraplex Form Factor |
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Environmental |
Temperature |
0 °C to 50 °C (operating), -20 °C to 80 °C (storage) |
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Humidity |
20 to 95% noncondensing |
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Power |
+5V @ 1.30 amps, +/- 12V @ 0.30 amps |
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Status |
Sync status via discrete logic |
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Connectors |
D-type connectors on carrier card |
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 Accessories
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Documentation |
Technical Reference Manual; installation and program information |
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Carrier Card |
QPLX-324-01 |
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Ordering Codes |
QSNCyyyyK-LCT-x |
Quadraplex-based PCM Bit Sync |
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Where: |
yyyy = bit rate, from 0010 to 3000
K = number of zeros for bit rate |
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Examples: |
30 Mbps = 30,000,000 bps = 3000 x104 = QSNC3004
3000 is the “yyyy” and the exponent of 4 (for 4 additional zeros) for K
10 bps = 10 bps = 0010 x100 = QSNC00100
0010 is the “yyyy” and the exponent of 0 (for no additional zeros) for K
Decimal points are supported for bit rates from 10 bps to 99 bps with the use of R as the decimal place (note that K will always be zero). Thus, 14.3 bps = 14.3 bps = 14R3 x100 = QSNC14R30
0010 is the “yyyy” and the exponent of 0 (for no additional zeros) for K |
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L = Loop Widths |
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Examples: |
0 |
0.05% |
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G |
1.60% |
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1 |
0.10% |
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H |
1.70% |
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2 |
0.20% |
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J |
1.80% |
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3 |
0.30% |
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K |
1.90% |
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4 |
0.40% |
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L |
2.00% |
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5 |
0.50% |
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M |
2.20% |
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6 |
0.60% |
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N |
2.40% |
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7 |
0.70% |
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P |
2.60% |
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8 |
0.80% |
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R |
2.80% |
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9 |
0.90% |
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S |
3.00% |
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A |
1.00% |
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T |
3.20% |
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B |
1.10% |
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V |
3.40% |
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C |
1.20% |
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W |
3.70% |
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D |
1.30% |
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X |
4.00% |
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E |
1.40% |
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Y |
4.50% |
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F |
1.50% |
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Z |
5.00% |
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Note: U indicates a unique configuration by the user |
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C = Input Code |
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Examples: |
0 |
NRZ-L |
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5 |
BIØ -S |
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A |
RNRZ-L, (2-11)-1 |
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1 |
NRZ-M |
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6 |
DM-M |
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B |
RNRZ-L, (2-15)-1 |
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2 |
NRZ-S |
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7 |
DM-S |
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C |
RNRZ-L, (2-20)-1 |
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3 |
BIØ -L |
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8 |
M² |
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D |
RNRZ-L, (2-23)-1 |
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4 |
BIØ -M |
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9 |
RZ |
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T = Tracking Loops |
Numbers are “times loop width” from variable “L” |
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Examples: |
0 |
1½ times |
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1 |
2 times |
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2 |
2½ times |
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3 |
3 times |
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4 |
4 times |
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5 |
5 times |
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6 |
10 times |
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Note: U indicates a unique configuration by the user. |
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X = Hardware Version |
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Unit Examples: |
QSNC11523-300-1 is a unit that accepts an NRZ-L input code at 1.152 Mbps, a loop bandwidth of .3%, and a tracking bandwidth of .45%. |
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QSNC85R3-XD5-1 is a unit that accepts an RNRZ-L, (2-23)-1 input code at 85.3 bps and has a loop bandwidth of 4.0% with a tracking range of 20%. |