AD8124ACPZ Analog Devices Inc, AD8124ACPZ Datasheet - Page 14

• Manufacturer Part Number: AD8124ACPZ
• Description: Triple Cat5 Cable Equalizer
• Manufacturer: Analog Devices Inc

Specifications of AD8124ACPZ

• Rohs Compliant: YES
• Bandwidth: 110MHz
• Supply Voltage Range: ± 4.5V To ± 5.5V
• No. Of Pins: 40
• Operating Temperature Range: -40°C To +85°C
• Peak Reflow Compatible (260 C): Yes
• Leaded Process Compatible: Yes
• Digital Ic Case Style: LFCSP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD8124
A suitable filter that uses a surface-mount ferrite bead is shown
in Figure 27, and its frequency response is shown in Figure 28.
Because the frequency response was taken using a 50 Ω network
analyzer and with only one 0.1 μF capacitor on the AD8124 side,
the actual amount of rejection provided by the filter in a real-world
application is different from that shown in Figure 28. The general
shape of the rejection curve, however, matches Figure 28, providing
substantially increased overall PSRR from approximately 5 MHz to
500 MHz, where it is most needed. One filter is required on each
of the two supplies (not one filter per supply pin).
Figure 28. Power Supply Filter Frequency Response in a 50 Ω System
–100
–120
–20
–40
–60
–80
SYSTEM
*ALL AD8124 SUPPLY PINS ARE INDIVIDUALLY
SUPPLY
DECOUPLED WITH A 0.1µF CAPACITOR.
0
10k
100k
Figure 27. Power Supply Filter
0.1µF
FREQUENCY (Hz)
4700pF
1M
2743021447
FAIR-RITE
10M
4700pF
TO AD8124*
100M
Rev. 0 | Page 14 of 16
LAYOUT AND POWER SUPPLY DECOUPLING
CONSIDERATIONS
Standard high speed PCB layout practices should be adhered
to when designing with the AD8124. A solid ground plane is
required and controlled impedance traces should be used when
interconnecting the high speed signals. Source termination resistors
on all outputs must be placed as close as possible to the output pins.
The exposed paddle on the underside of the AD8124 must be
connected to a pad that connects to at least one PCB plane.
Several thermal vias should be used to make the connection
between the pad and the plane(s).
High quality 0.1 μF power supply decoupling capacitors should
be placed as close as possible to all supply pins. Small surface-
mount ceramic capacitors should be used, and tantalum capacitors
are recommended for bulk supply decoupling.
POWER-DOWN
The power-down feature is intended to be used to reduce power
consumption when a particular device is not in use and does
not place the output in a high-Z state when asserted. The input
logic levels and supply current in power-down mode are presented
in the Power Supply section of Table 1.