MT9076BPR1 Просмотр технического описания (PDF) - Zarlink Semiconductor Inc

Номер в каталоге

Компоненты Описание

производитель

MT9076BPR1

T1/E1/J1 3.3 V Single Chip Transceiver

Zarlink Semiconductor Inc 

MT9076B

Data Sheet

1.3 20 MHz Clock

The MT9076 requires a 20 MHz clock. This may be provided by a 50 ppm oscillator as per Figure 8.

+3.3 V

OSC1

20 MHz

OUT

Vdd

GND

.1 µF

OSC2

(open)

Figure 8 - Clock Oscillator Circuit

Alternatively, a crystal oscillator may be used. A complete oscillator circuit made up of a crystal, resistors and

capacitors is shown in Figure 9. The crystal specification is as follows.

Frequency:

Tolerance:

Oscillation Mode:

Resonance Mode:

Load Capacitance:

Maximum Series Resistance:

Approximate Drive Level:

20 MHz

50 ppm

Fundamental

Parallel

32 pF

35 Ω

1 mW

OSC1

20 MHz

1MΩ

OSC2

56 pF

39 pF

100 Ω

1 µH*

Note: the 1 µH inductor is optional

Figure 9 - Crystal Oscillator Circuit

1.4 Phase Lock Loop (PLL)

The MT9076 contains a PLL, which can be locked to either an input 4.096 MHz clock or the extracted line clock.

The PLL will attenuate jitter from less than 2.5 Hz and roll-off at a rate of 20 dB/decade. Its intrinsic jitter is less than

0.02 UI. The PLL will meet the jitter transfer characteristics as specified by AT&T document TR 62411 and the

relevant recommendations as shown in Figure 3.

27

Zarlink Semiconductor Inc.

Share Link: