AD9510SLASHPCB datasheet(58/60 Pages) AD

58 / 60 page

AD9510

Rev. A | Page 58 of 60

Because of the limitations of single-ended CMOS clocking,

consider using differential outputs when driving high speed

signals over long traces. The AD9510 offers both LVPECL and

LVDS outputs, which are better suited for driving long traces

where the inherent noise immunity of differential signaling

provides superior performance for clocking converters.

LVPECL CLOCK DISTRIBUTION

The low voltage, positive emitter-coupled, logic (LVPECL)

outputs of the AD9510 provide the lowest jitter clock signals

available from the AD9510. The LVPECL outputs (because they

are open emitter) require a dc termination to bias the output

transistors. A simplified equivalent circuit in Figure 41 shows

the LVPECL output stage.

In most applications, a standard LVPECL far-end termination is

recommended, as shown in Figure 56. The resistor network is

designed to match the transmission line impedance (50 Ω) and

the desired switching threshold (1.3 V).

3.3V

LVPECL

SINGLE-ENDED

(NOT COUPLED)

3.3V

LVPECL

127

VT = VCC – 1.3V

Figure 56. LVPECL Far-End Termination

3.3V

LVPECL

DIFFERENTIAL

(COUPLED)

3.3V

LVPECL

100

0.1nF

200

Figure 57. LVPECL with Parallel Transmission Line

LVDS CLOCK DISTRIBUTION

Low voltage differential signaling (LVDS) is a second

differential output option for the AD9510. LVDS uses a current

mode output stage with several user-selectable current levels.

The normal value (default) for this current is 3.5 mA, which

yields 350 mV output swing across a 100 Ω resistor. The LVDS

outputs meet or exceed all ANSI/TIA/EIA-644 specifications.

A recommended termination circuit for the LVDS outputs is

shown in Figure 58.

3.3V

LVDS

100

DIFFERENTIAL (COUPLED)

3.3V

LVDS

100

Figure 58. LVDS Output Termination

See Application Note AN-586 on the ADI website at

www.analog.com for more information on LVDS.

POWER AND GROUNDING CONSIDERATIONS AND

POWER SUPPLY REJECTION

Many applications seek high speed and performance under

less than ideal operating conditions. In these application

circuits, the implementation and construction of the PCB is as

important as the circuit design. Proper RF techniques must be

used for device selection, placement, and routing, as well as for

power supply bypassing and grounding to ensure optimum

performance.

AD9510/PCB 数据表(PDF) 58 Page - Analog Devices

AD9510/PCB 数据表(HTML) 58 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

数据表下载

链接网址

AD9510/PCB 数据表(PDF) 58 Page - Analog Devices

AD9510/PCB 数据表(HTML) 58 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

数据表 下载

链接网址

数据表下载