MC145574AAER2 Freescale Semiconductor, MC145574AAER2 Datasheet - Page 21

• Manufacturer Part Number: MC145574AAER2
• Manufacturer: Freescale Semiconductor

Specifications of MC145574AAER2

• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / Rohs Status: Compliant

MOTOROLA
2.5
2.6
MC145574
The essence of this configuration is that a restriction is placed on the distance between the TEs. The
distance, D3 (as shown in Figure 2–3), corresponds to the maximum distance between the grouping
of TEs. CCITT I.430, ETSI ETS 300012, and ANSI T1.605 specify a distance of 25 – 50 meters for
the separation between the TEs, and a distance of 500 meters for the total length. These distances
correspond to the distances D3 and D4 as shown in Figure 2–3.
Note that the “NT configured” MC145574 should be placed in the adaptive timing mode for this configu-
ration. This is achieved by holding the FIX pin low.
BRANCHED PASSIVE BUS OPERATION
A wiring configuration which has somewhat similar characteristics to those of the “extended passive
bus” is known as the “branched passive bus” and is shown in Figure 2–4. In this configuration the
branching occurs at the end of the bus. The branching occurs after a distance D1 from the NT. The
distance D5 corresponds to the maximum separation between the TEs.
NT1 STAR MODE OF OPERATION
A wiring configuration which may be used to support multiple T interfaces is known as the “NT1 Star
mode of operation.” This mode of operation is supported by the MC145574. This mode is described
in Section 11. Note that the NT1 Star mode contains multiple NTs. Each of these NTs can be connected
to either a passive bus (short, extended, or branched) or to a single TE.
TE
RxN
RxP
TxN
TxP
<
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 2–4. Branched Passive Bus
TxP TxN RxP RxN
Go to: www.freescale.com
D5
MC145574
TE
MC145574
>
<
TR
TR
D1
TR
TR
>
TxP
TxN
RxP
RxN
MC145574
NT
2–3