T7256 Agere Systems, T7256 Datasheet - Page 3

• Manufacturer Part Number: T7256
• Description: (T7234 - T7256) Compliance
• Manufacturer: Agere Systems

Advisory
July 1998
(Refer to the T7234, T7237, and T7256 ISDN transceiver data sheets.)
The Technology and Telecommunications Standard sections below denote the differences between the T7234,
T7237, and T7256 and the T7234A, T7237A, and T7256A.
Technology
Telecommunication Standard
In 1996, the European Telecommunications Standards Institute (ETSI) added a microinterruption immunity
requirement to ETR 080 (Sections 5.4.5 and 6.2.5).
Section 5.4.5 in ETSI ETR 080 states the following:
Section 6.2.5 in ETSI ETR 080 states that:
The SCNT1 family of U-interface transceivers was upgraded to fully comply with this standard. The devices
have been given an A suffix (T7234A, T7237A, and T7256A).
A proposal was added to the Living List (which is intended to collect issues and observations for a possible
future update of ETSI ETR 080) to change the value of the microinterruption from 5 ms to 10 ms. The current
SCNT1 family of U-interface transceivers (T7234A/T7237A/T7256A) from Lucent Technologies Microelectron-
ics Group meets and exceeds this new requirement.
The above change to the SCNT1 family of transceivers has been fully verified, and test reports are available
upon request.
The T-7234- - -ML, T-7237- - -ML, and T-7256- - -ML2 are 0.9 µm CMOS technology devices.
The T-7234A- -ML, T-7237A- -ML, and T-7256A- -ML are 0.6 µm CMOS technology devices.
A microinterruption is a temporary line interruption due to external mechanical activity on the copper wires
constituting the transmission path.
The effect of a microinterruption on the transmission system can be a failure of the digital transmission link.
The objective of this requirement is that the presence of a microinterruption of specified maximum length
shall not deactivate the system, and the system shall activate if it has deactivated due to longer interruption.
A system shall tolerate a microinterruption up to t = 5 ms, when simulated with a repetition interval of
t = 5 ms.
T7234, T7237, and T7256
Data Sheet Advisory