YTD439 Datasheet, PDF (4/15 Pages) List of Unclassifed Manufacturers – ISDN BRI controller for Terminal Equipment with built-in DSU

❑ Block Diagram
❍ User-Network Interface Block Diagram
YTD439 is best-suited for applications in terminal equipment with built-in DSU (TA, TE1)
such as terminal adapters and remote routers with built-in DSUs.
YTD439 contains a DSU function, which is necessary between the ISDN switch and the user-
network interface, and layer 1 and layer 2 functions, which are required of ISDN system
equipment. By adding minimal peripheral parts such as microprocessor and CODEC, terminal
equipment can be optimally configured.
R
TE2
S/T
TE1
TA with
built-in DSU
S
T
U
TE1
(ISDN terminal)
R
S
NT2
(PBX, etc.)
NT1
(DSU)
TE2
TA
(Non-ISDN (Terminal adapter)
terminal)
S/T
TE1
R
TE2
S/T
U
User's premises
TE1
TA with
built-in DSU
ISDN
Network
YTD439
YTD436 or
YTD423 + YTD421
YTD428 (DSU)
-4-