ICS1893BF Data Sheet - Release
Chapter 8 Pin Diagram, Listings, and Descriptions
Table 8-3. ICS1893BF Configuration Pins
Signal Name
REF_IN
Pin No.
47
Signal Description
Frequency Reference Input: 25 MHz Input Clock or Crystal
Frequency Reference Output for Crystal
System Reset (active low)
REF_OUT
RESETn
46
23
8.2.1 Transformer Interface Pins
Transformer connections on the ICS1893BF signals TP_AP, TP_AN, TP_BP and TP_BN are shown in
Table 8.4. The previous TP_CT pin on the ICS1893AF is not used with the ICS1893BF. The typical Twisted
Pair Transformers connections are shown in Chapter 5. The transformer must be 1:1 ratio and symetrical
for 10/100 MDI/MDIX applications since the transmit twisted pair and receive twisted pair are
interchangeable. ICS1893 PHYs do not have power connections to the transformer. All transformer power
is supplied by the ICS1893. Note the twisted pair are polarity sensitive and must connect to the RJ45 with
the same polarity as shown in the figure.
Table 8-4 lists the pins for the transformer interface group of pins.
Table 8-4. ICS1893BF Transformer Interface Pins
Signal Name
TP_AP
Pin No.
12
Signal Description
Twisted Pair A Positive
Twisted Pair A Negative
Twisted Pair B Positive
Twisted Pair B Negative
TP_AN
13
TP_BP
16
TP_BN
15
8.2.2 Multi-Function (Multiplexed) Pins: PHY Address and LED Pins
Table 8-5 lists the pins for the multi-function group of pins (that is, the multiplexed PHY Address / LED pins).
Note:
1. During either a power-on reset or a hardware reset, each multi-function configuration pin is an input
that is sampled when the ICS1893BF exits the reset state. After sampling is complete, these pins are
output pins that can drive status LEDs.
2. A software reset does not affect the state of a multi-function configuration pin. During a software reset,
all multi-function configuration pins are outputs.
3. Each multi-function configuration pin must be pulled either up or down with a resistor to establish the
address of the ICS1893BF. LEDs placed in series with these resistors provide a designated status
indicator.
Caution: All pins listed in Table 8-5 must not float.
4. As outputs, the asserted state of a multi-function configuration pin is the inverse of the sense sampled
during reset. This inversion provides a signal that can illuminate an LED during an asserted state. For
example, if a multi-function configuration pin is pulled down to ground through an LED and a
current-limiting resistor, then the sampled sense of the input is low. To illuminate an LED for the
asserted state requires the output to be high.
ICS1893BF, Rev. E, 8/11/09
August, 2009
Copyright © 2009, IDT, Inc.
All rights reserved.
92
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
