LXT381

Features:

· Octal E1 short haul line interface per ITU G.703
· Single rail supply voltage of 3.3V with 5V I/O capability
· Low power consumption of <100 mW per channel (typ.)
· 75Ω/120Ω TX operation without component changes
· Transmit return loss complies with ETSI ETS 300 166
· Hitless Protection Switching (HPS)
· Driver short circuit current limiter (<50 mA RMS)
· Differential receiver with 15dB of signal to noise interference margin
· Data recovery with no need for external reference clock
· Analog LOS detection per ITU G.775
· Simple hardware control mode
· JTAG Boundary Scan test port per IEEE 1149.4
· Small footprint 144 pin LQFP or 160 pin PBGA package


Application

· Synchronous Digital Hierarchy (SDH) E1 tributary interfaces
· Public switching trunk line interfaces
· Digital Access Cross Connects (DACS)
· Microwave transmission systems


Pinout




Specifications

Parameter	SYMBOL	Min.	Max.	Unit
DC supply voltage	Vcc0, Vcc1, Tvcc 0- 7	-0.5	4.0	V
DC supply voltage	Vccio0, Vccio1,	-0.5	7.0	V
Input voltage on any digital pin	Vin	GND-0.5 GND-0.5	VCCIO0 + 0.5 VCCIO1 + 0.5	V V
Input voltage on RTIP, RRING1	Vin	GND-0.5	VCC0 + 0.5 VCC1 + 0.5	V
ESD voltage on any Pin 2	Vin	2000	-	V
Transient latch-up current on any pin	Iin	-	100	mA
Input current on any digital pin 3	Iin	-10	10	mA
DC input current on TTIP, TRING 3	Iin		±100	mA
DC input current on RTIP, RRING 3	Iin	-	±100	mA
Storage temperature	TSTOR	-65	+150
Maximum package power dissipation	PP		850	mW
Thermal resistance, junction to ambient, 144 pin LQFP package			28	/W
Thermal resistance, junction to ambient, 160 pin PBGA package			28	/W

Caution: Exceeding these values may cause permanent damage.
Caution: Functional operation under these conditions is not implied.
Caution: Exposure to maximum rating conditions for extended periods may affect device reliability.

1. Referenced to ground.
2. Human body model.
3. Constant input current.


Description

The LXT381 is an octal short haul analog Line Interface Unit for ITU G.703 2.048 Mbit/sec. transmission systems. It incorporates eight independent receivers and eight independent transmitters in a single LQFP-144 or PBGA-160 package.

The LXT381 transmit output drivers provide low impedance, constant during marks and spaces and constant pulse amplitudes independent of supply voltage variations.

The LXT381 may be configured for unbalanced 75Ω or for balanced 120Ω systems without external component changes in the transmit section. The transmit return loss performance exceeds latest ETSI return loss recommendations such as ETS 300166.

The LXT381 features a differential data receiver architecture with high noise interference margin. The receivers use peak detection and a variable threshold for reliable data recovery down to 500 mV or up to 12 dB of cable attenuation.

Each receiver incorporates an analog Loss Of Signal (LOS) processor that meets latest ITU G.775 standard.The fast power down mode of all transmitters LXT381 allows the implementation of Hitless Protection Switching (HPS) application without the use of relays.