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BLOCK DIAGRAM

YTD428

DSU section

Call control

circuit

U ref. pt.

driver

Layer 3 information

(Bch data)

I.430 TTL I/F

(No transformer is requied)

YTD418 or

YTD423

I/F

switch

CT

and

LT

U ref.

pt. I/F

T ref.

pt. I/F

L1

TA / TB

RA / RB

L2

YTD428

DSU section

Call control

circuit

U ref. pt.

driver

YTD418 or

YTD423

I/F

switch

CT

and

LT

U ref.

pt. I/F

T ref.

pt. I/F

TTL I/F

(No transformer is required)

L1

TA / TB

RA / RB

L2

Layer 3 information

(Bch data)

s

Configuration example of a device with a built-in DSU that uses an I.430 TTL

interface at the T ref. pt.

When using YTD428 with YAMAHA'S S/T reference point interface LSI to create a device with a built-in

DSU, they can be connected directly through the I.430 TTL interface. This results in a reduction of pulse

transformer parts.

s

Example of using T reference point driver / receiver section independently

By setting the Interface switch, the drive / receiver of the T reference point interface section can be separated

from the circuit termination (CT) and line termination (LT) section and be used independently.

The user can enable or disable this feature as necessary.