ABB SDCS-IOB-22 3BSE005177R0001 Output expansion card

Another view of the circuit is that the phase shifter implements the zero required for frequency compensation of a second-order phase-locked loop, and this zero is placed in the feedback path and, thus, does not appear in the closed-loop transfer function. Jitter peaking in a conventional second-order phase-locked loop is caused by the presence of this zero in the closed-loop transfer function. Because this circuit has no zero in the closed-loop transfer, jitter peaking is minimized. The delay and phase loops together simultaneously provide wideband jitter accommodation and narrow-band jitter filtering. The linearized block diagram in Figure 13 shows that the jitter transfer function, Z(s)/X(s), is a second-order low-pass providing excellent filtering. Note that the jitter transfer has no zero, unlike an ordinary second-order phase-locked loop. This means that the main PLL has virtually zero jitter peaking (see Figure 14). This makes this circuit ideal for signal regenerator applications where jitter peaking in a cascade of regenerators can contribute to hazardous jitter accumulation.

The delay and phase loops

 contribute to overall jitter accommodation. At low frequencies of input jitter on the data signal, the integrator in the loop filter provides high gain to track large jitter amplitudes with small phase error. In this case, the VCO is frequency modulated and jitter is tracked as in an ordinary phase-locked loop. The amount of low frequency jitter that can be tracked is a function of the VCO tuning range. A wider tuning range gives larger accommodation of low frequency jitter. The internal loop control voltage remains small for small phase errors; therefore, the phase shifter remains close to the center of its range and thus contributes little to the low frequency jitter accommodation

The error transfer, e(s)/X(s)

has the same high-pass form as an ordinary phase-locked loop. This transfer function is free to be optimized to give excellent wideband jitter accommodation, because the jitter transfer function, Z(s)/X(s), provides the narrow-band jitter filtering.

Company introduction

Temporal Ming sheng automation equipment co., LTD. Was established in April 02, 2021, registered jiujiang ruichang city in jiangxi province, east yi road no. 23 lake farmers 401 mall, the legal representative person Zhou Zuochen.

[Main Products]

Main products: PLC and DCS system spare parts modules of world famous brands

①Allen-Bradley 1756、1746、1747、1771、1785

②Schneider 140 Series PLC module

③General electric GE

IC693 IC697 IC698 Series PLC module

DS200 DS3800 DS215 IS200 IS215 IS220 Series gas turbine module

VMIVME Control module of series

④Bently：3500 series cards 3500/22M、3500/15、3500/92 And other products

⑤ICS TRIPLEX

⑥ABB Robots. FANUC Robots、YASKAWA Robots、KUKA Robots、Mitsubishi Robots、OTC Robots、Panasonic Robots、MOTOMAN Robots。

⑦EMERSON：Spare parts for OVATION system, WDPF system and MAX1000 system.

⑧ Invensys Foxboro: I/A Series system, FBM (field input/output module) sequential control, ladder logic control, accident recall processing, digital analog conversion, input/output signal processing, data communication and processing, etc. Invensys Triconex: redundant fault-tolerant control system, Zui modern fault-tolerant controller based on triple module redundancy (TMR) structure.

⑨Woodward：505 series governor 9907-164 And other products

⑩Bosch Rexroth：Indramat，I/O module,PLC CPU,Motors, drives and other products. 

◆Motorola：MVME 162、MVME 167、MVME1772、MVME177and other products.