EQCO875SC.3/EQCO850SC.3
EQCO875SC.3/EQCO850SC.3 Single-Coax Transceiver for
Fast Ethernet
Features
• Combined Transmitter and Receiver with an
Integrated Equalizer to Form a Full-Duplex
Bidirectional Connection over a Single 75Ω Coax
Cable (EQCO875SC.3) or 50Ω Coax Cable
(EQCO850SC.3)
• Compatible with FX Version of Fast Ethernet
• Low-Power: 205 mW from Single 3.3V Supply
• Integrated Termination Resistors for Low External
Discrete Count
• Fully Supports PoE-Based Power and Data
Signal Distribution Over Coax
• 16-Pin, 0.65 mm Pin Pitch, 4 mm QFN Package
• Pb-Free and RoHS Compliant
Applications
This solution is useful and economical for many
markets and applications, including the following:
• Camera Networks
- Home Security, Surveillance, Industrial/
Inspection, Medical Cameras
• Home Networking over Coax Infrastructure
- When Cat5 or Cat6 cabling is not available
and existing 75Ω coax is not used for analog
TV signals
• TV, STB, PVR Connections Including Inter-Room
Links
TABLE 1:
TYPICAL DEVICE PERFORMANCE FOR EQCO875SC.3
Version
EQCO875SC.3 Range Using
RG11
225m
RG6 (Ø 5 mm)
150m
EQCO875SC.3
TABLE 2:
TYPICAL DEVICE PERFORMANCE FOR EQCO850SC.3
Version
EQCO850SC.3 Range Using
RG174
40m
RTK
70m
RG58
70m
EQCO850SC.3
2009-2016 Microchip Technology Inc.
DS60001314A-page 1
EQCO875SC.3/EQCO850SC.3
Table of Contents
1.0
2.0
3.0
4.0
Device Overview .......................................................................................................................................................................... 3
Application Information ................................................................................................................................................................. 7
Electrical Characteristics .............................................................................................................................................................. 9
Packaging................................................................................................................................................................................... 11
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced.
If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at
docerrors@microchip.com.
We welcome your feedback.
Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision
of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site;
http://www.microchip.com
• Your local Microchip sales office (see last page)
When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are
using.
Customer Notification System
Register on our web site at
www.microchip.com
to receive the most current information on all of our products.
DS60001314A-page 2
2009-2016 Microchip Technology Inc.
EQCO875SC.3/EQCO850SC.3
1.0
DEVICE OVERVIEW
The EQCO875SC.3 single-coax transceiver is
designed to simultaneously transmit and receive
signals on a single 75Ω coax cable for Fast Ethernet. A
sister product, the EQCO850SC.3, can achieve similar
performance when used in 50Ω coaxial systems.
The EQCO875SC.3 is ideally suited for Fast Ethernet
connections over a 75Ω coax cable at a 125 Mbps data
rate. The EQCO875SC.3 connects seamlessly to any FX-
compliant physical layer controller (PHY). For correct
operation, the signals are expected to be 4B/5B encoded,
DC balanced and to have a bit rate of 125 Mbps.
This EQCO875SC.3 is useful and economical for
connecting remote PoE-enabled Fast Ethernet IP
cameras and other Ethernet over Coax applications.
Figure 1-1
illustrates a typical Ethernet Coaxial
connection:
FIGURE 1-1:
COAXIAL ETHERNET PMD CONNECTION
Up to 225 meters
IEEE 802.3
FX
Compliant
PHY
IEEE 802.3
FX
Compliant
PHY
EQCO875SC
75Ω Coax
(including inline
connectors as required)
EQCO875SC
2009-2016 Microchip Technology Inc.
DS60001314A-page 3
EQCO875SC.3/EQCO850SC.3
FIGURE 1-2:
EQCO875SC.3 PIN DIAGRAM (VIEWED FROM TOP)
(1)
CCUT
16
1
DVCC
15
OPT0
14
DGND
13
12
SDOp
AVCC
SDIO
2
11
SDOn
REF
3
EQCO875SC.3
GND TAB
10
SDIp
AGND
4
5
OPT1
9
8
NC
SDIn
6
CLK
7
DAT
Note 1:
Devices named EQCO850SC.2 can be used for all applications contained in this data sheet. They are the
same in all aspects.
TABLE 1-1:
Pin Number
(TAB)
15
13
1
EQCO875SC.3 PIN DESCRIPTIONS
Pin Name
GND
DVCC
DGND
AVCC
Signal Type
Power
Power
Power
Power
Description
Connect to ground of power supply.
Digital VCC. Connect to +3.3V of power supply.
Digital GND. Connect to ground of power supply.
Analog VCC.
Connect to +3.3V of power supply via ferrite bead (RF choke)
and capacitor to cable outer screen.
Analog GND.
Connect to cable outer screen.
Serial Input/Output.
Connect to center conductor of 75Ω coax cable.
Reference. Connect through 75Ω resistor (or impedance
matched to cable) to cable outer screen.
Do not connect.
Positive/negative differential serial input.
Connect to the Ethernet PHY FX Out pins.
Positive/negative differential serial output.
Connect to the Ethernet PHY FX In pins.
Connect Opt0 to DGND and Opt1 to DVCC to enable Fast
Ethernet mode.
Used for production test. Connect to DGND.
Connect to DVCC.
4
2
3
8
10, 9
12, 11
14, 5
6, 7
16
AGND
SDIO
REF
NC
SDIp/SDIn
SDOp/SDOn
OPT0, OPT1
CLK, DAT
CCUT
Power
Bidirectional
Bidirectional
Output
Input
Output
Input
Input
Analog
DS60001314A-page 4
2009-2016 Microchip Technology Inc.
EQCO875SC.3/EQCO850SC.3
FIGURE 1-3:
EQCO875SC.3 BLOCK DIAGRAM SHOWING ELECTRICAL CONNECTIONS
EQCO875SC.3
SDIp
SDIn
Input
Pre-Driver
Active Signal
Splitter/Combiner
SDIO
REF
Transmit
Wake-Up
Detection
Equalizer
Core
SDOp
SDOn
RX Output
Driver
1.1
SDIp/SDIn
1.3
SDOp/SDOn
SDIp/SDIn together form a differential input pair. The
serial data received on these pins will be transmitted on
SDIO. The Input Pre-Driver automatically corrects for
variations in signal levels and different edge slew rates at
these inputs before they go into the Active Splitter/
Combiner for transmission over the coax.
Both SDIp and SDIn inputs are differentially terminated by
110Ω on-chip. The center of the 110Ω is connected to
DGND with a 10 kΩ resistor for DC biasing. The inputs
also have protection diodes to ground for ESD purposes.
These inputs should always be capacitively coupled to the
FX output of the Ethernet PHY. A Transmit Wake-Up
detection circuit puts both the Input Pre-Driver and the
Active Signal Splitter/Combiner into a low-power mode
when no signal is detected on the SDIp/SDIn signal pair.
SDOp/SDOn together form a differential pair outputting
the reconstructed far-end transmit signal. The
EQCO850SC-HS uses LVDS drivers with source
matching for a 100Ω transmission line. This LVDS
signal can normally be connected (subject to input
common-mode requirements) directly to the RX signal
pair of a standard LVDS receiver.
1.4
OPT0, OPT1
Connect Opt0 to DGND and Opt1 to DVCC to enable
Fast Ethernet mode.
1.5
CLK, DAT Pins
1.2
SDIO/REF
These pins are normally used to access an internal
register during production test. Connect them to DGND
for normal operation. They should not be left floating.
The signal on the SDIO pin is the sum of the incoming
signal (i.e. the signal transmitted by the EQCO875SC on
the far-end side of the coax) and the outgoing signal (i.e.
the signal created based on SDIp/SDIn). The far-end
signal is extracted by subtraction of the near-end signal,
and it is this voltage that the equalizer analyses and
adaptively equalizes for level and frequency response
based on the knowledge that the originating signal is 4B/
5B encoded before transmission.
The REF signal carries a precise anti-phase current to the
transmit current on SDIO. REF must be connected
directly to AGND at the connector (see
Figure 3-2)
via a
resistor precisely matched to the impedance of the
coaxial cable used.
2009-2016 Microchip Technology Inc.
DS60001314A-page 5
京公网安备 11010802033920号
EEWORLD
