Mitel NWK954 manual Ac Electrical Characteristics, EXTERNAL COMPONENTS See Fig, fTCLK, tWRES

NWK954

AC ELECTRICAL CHARACTERISTICS

Recommended Operating Conditions apply except where otherwise stated

TXCLK and RESET_N

Characteristic				Symbol		Value		Units		Conditions
			Min.		Typ.	Max.
TXCLKIN
Frequency				fTCLK		25 ± 100ppm			MHz
Duty cycle					45		55		%
RESET_N
Pulse width				tWRES	100	-	-		ns
TXOP/TXON
				Characteristic							Reference
The differential output voltage shall be in the range 950mV to 1050mV.											TP-PMD 9.1.2.2
The differential overshoot shall not exceed 5%.											TP-PMD 9.1.3
Overshoot transients must decay to within 1% of the steady state voltage within 8ns of the start of the											TP-PMD 9.1.3
differential signal transition.
The signal amplitude symmetry shall be in the range 98% to 102%.											TP-PMD 9.1.4
The return loss shall be greater than 16dB from 2MHz to 30MHz.											TP-PMD 9.1.5
The return loss shall be greater than 16-20 log(f/30MHz)dB from 30MHz to 60MHz											TP-PMD 9.1.5
The return loss shall be greater than 10dB from 60MHz to 80MHz.											TP-PMD 9.1.5
The rise and fall times measured from 10% to 90% of the steady state output voltage shall be between											TP-PMD 9.1.6
3ns and 5ns.
Difference between max. and min. rise and fall times shall be less than 0·5ns.											TP-PMD 9.1.6
Duty cycle distortion must be less than 60·25ns measured at 50% of the steady state output voltage for											TP-PMD 9.1.8
a data sequence of 01010101 (NRZ)
Total transmit jitter, including duty cycle distortion and baseline wander, must be less than 1·4ns p-p											TP-PMD 9.1.9
RXIP/RXIN
				Characteristic							Reference
The return loss shall be greater than 16dB from 2MHz to 30MHz.											TP-PMD 9.2.2
The retum loss shall be greater than 16-20 log(f/30MHz)dB from 30MHz to 60MHz.											TP-PMD 9.2.2
The return loss shall be greater than 10dB from 60MHz to 80MHz											TP-PMD 9.2.2
EXTERNAL COMPONENTS (See Fig. 8)
Component	Value	Tol.					Description
R1	16·2Ω	1%	Receiver impedance matching resistor network.
R2	34·0Ω	1%	Receiver impedance matching resistor network.
R3	50Ω	1%	Transmitter load resistors.
R4	1·2kΩ	1%	Sets the transmitter output current.
R5	5kΩ	5%	This resistor is required even if the RESET_N signal is not used externally.
R6	10kΩ	5%	Optional pull-downs on backplane enable signals. These outputs are normally active low.
			Each output can be independently changed to active high by the addition of this resistor.
R7	200Ω min*	5%	Pull-ups required on open drain expansion port outputs.
R8			Series resistors. May be required in some applications where the expansion ports are used.*
C1, C3	0·01μF
C2	0·1μF
* Refer to Mitel						Table 10

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