ADN2804 Просмотр технического описания (PDF) - Analog Devices

Номер в каталоге

Компоненты Описание

производитель

ADN2804

622 Mbps Clock and Data Recovery IC with Integrated Limiting Amplifier

Analog Devices 

Data Sheet

APPLICATIONS INFORMATION

PCB DESIGN GUIDELINES

Proper RF PCB design techniques must be used for optimal

performance.

Power Supply Connections and Ground Planes

Use of one low impedance ground plane is recommended. The

VEE pins should be soldered directly to the ground plane to

reduce series inductance. If the ground plane is an internal

plane and connections to the ground plane are made through

vias, multiple vias can be used in parallel to reduce the series

inductance, especially on Pin 23, which is the ground return for

the output buffers. The exposed pad should be connected to the

GND plane using plugged vias so that solder does not leak

through the vias during reflow.

Use of a 22 μF electrolytic capacitor between VCC and VEE is

recommended at the location where the 3.3 V supply enters the

PCB. When using 0.1 μF and 1 nF ceramic chip capacitors, they

should be placed between ADN2804 supply pins VCC and VEE,

as close as possible to the ADN2804 VCC pins.

ADN2804

If connections to the supply and ground are made through

vias, the use of multiple vias in parallel helps to reduce series

inductance, especially on Pin 24, which supplies power to the

high speed CLKOUTP/CLKOUTN and DATAOUTP/

DATAOUTN output buffers. Refer to Figure 24 for the

recommended connections.

By placing the power supply and GND planes adjacent to each

other and using close spacing between the planes, excellent high

frequency decoupling can be realized. The capacitance is given

by

CPLANE  0.88ε r A/d pF

where:

r is the dielectric constant of the PCB material.

A is the area of the overlap of power and GND planes (cm2).

d is the separation between planes (mm).

For FR-4, r = 4.4 and d = 0.25 mm; therefore,

CPLANE ~ 15.5A (pF)

VCC

+ 22µF

0.1µF 1nF

50Ω TRANSMISSION LINES

DATAOUTP

DATAOUTN

CLKOUTP

CLKOUTN

0.1µF

1nF

0.1µF

TIA

50Ω 1.6µF

VCC

1nF 0.1µF

TEST1

VCC

VREF

NIN

PIN

SLICEP

SLICEN

VEE

1

2

3

4

5

6

7

8

24

EXPOSED PAD 23

TIED OFF TO 22

VEE PLANE 21

WITH VIAS 20

19

18

17

VCC

VEE

LOS

SDA

SCK

SADDR5

VCC

VEE

I2C CONTROLLER

I2C CONTROLLER

VCC

µC

1nF 0.1µF

50Ω 1.6µF

RTH

VCC

0.1µF 1nF

µC

0.47µF ±20%

>300MΩ INSULATION RESISTANCE

Figure 24. Typical ADN2804 Applications Circuit

Rev. D | Page 21 of 24

Share Link: