ICS1893Y-10LF IDT, Integrated Device Technology Inc, ICS1893Y-10LF Datasheet - Page 32

• Manufacturer Part Number: ICS1893Y-10LF
• Description: PHYCEIVER LOW PWR 3.3V 64-TQFP
• Manufacturer: IDT, Integrated Device Technology Inc
• Series: PHYceiver™r
• Type: PHY Transceiverr

Specifications of ICS1893Y-10LF

• Protocol: MII
• Voltage - Supply: 3.14 V ~ 3.47 V
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Drivers/receivers: -
• Other names: 1893Y-10LF; 800-1935-5; ICS1893Y-10LF

5.5.1 Twisted-Pair Transmitter Interface
ICS1893Y-10 Rev F 1/20/04
The twisted-pair transmitter driver uses an H-bridge configuration, which requires that the transmit
transformer not have a choke on the chip side. ICS suggests any of the following for the H-bridge:
•
•
•
Figure 5-1
•
•
•
Note:
1. If the transmit transformer has a choke, put a choke on the RJ-45 side. Do not put a choke on the
2. Keep all TX traces as short as possible.
3. When making board traces, 50 Ω -characteristic impedance is desirable
4. Include a 0 Ω resistor in series with TP_CT. (Some systems work better without the TP_CT connection.)
Figure 5-1. ICS1893Y-10 Transmit Twisted Pair
ICS1893Y-
Halo TG22S012ND transformer
Transpower HB617-LP transformer
Pulse 68517 transformer, which can be turned around to move the choke windings to the RJ-45 side
Two 61.9 Ω 1% resistors are in series, with a 120-nH 5% inductor between them. These components
form a network that connects across both the transformer and the ICS1893Y-10 TP_TXP and TP_TXN
pins.
The ICS1893Y-10 supplies the power to the transformer. (No VDD connection is required.)
The ICS1893Y-10 TP_CT pin is connected directly to the transformer transmit center tap connection and
is bypassed to ground with a 100-pF capacitor. The transformer center tap must not connect to the
resistor/inductor network.
ICS1893Y-10 side of the transformer for the transmit windings.
TP_TXP 5
TP_TXN 6
ICS1893Y-10 Data Sheet - Release
TP_CT 3
shows the design for the ICS1893Y-10 twisted-pair transmitter interface.
Ideally, for these traces Z
Copyright © 2004, Integrated Circuit Systems, Inc.
61.9 Ω 1%
61.9 Ω 1%
120 nH
o
0 Ω
System Ground Plane
= 50 Ω .
All rights reserved.
32
Center
Tap
1:1
100 pF
Chassis Ground Plane
75 Ω
0.1 µ F
Separate Ground Plane
Chapter 5 Interface Overviews
To RJ-45
January, 2004