Using DS2148/DS21348 as Repeater

May 29, 2002

Abstract: Application note 387 describes the use of the Maxim DS2148/DS21348 as a T1 or E1 repeater. A simple circuit diagram shows typical connections. Configurations for Hardware Mode and Software Mode are also provided.

Introduction

This application note describes the register settings for Maxim's DS2148 and DS21348 (E1/T1/J1 line interface units) as a repeater for T1 or E1 operation. This can be accomplished with the device in either hardware or software mode.

The receive sensitivity for these two LIUs is programmable and is as much as -36dB for T1 applications and -43dB for E1 applications.

To simplify the design, it is recommended to use a 2.048MHz oscillator and use the internal register settings of the DS2148 and the DS21348 to convert the MCLK to 1.544MHz for T1 applications.

Figure 1. Typical T1/E1 repeater application.

The configuration settings of the DS2148 or the DS21348 in hardware mode are:

Hardware Mode Settings for T1	Hardware Mode Settings for E1
MCLK = 2.048MHz	MCLK = 2.048MHz
BIS1 = 1, BIS0 = 1	BIS1 = 1, BIS0 = 1
CES = 0	CES = 0
DJA = 0 or 1 (application dependent)	DJA = 0 or 1 (application dependent)
HBE = 1	HBE = 1
JAS = 0 or 1 (application dependent)	JAS = 0 or 1 (application dependent)
NRZE = 0	NRZE = 0
TPD = 0	TPD = 0
L2 = L1 = L0 = 0	L2/L1/L0 (application dependent)
TX1 = 0, TX0 = 0	TX1 = 0, TX0 = 0
LOOP1 = 0, LOOP0 = 0	LOOP1 = 0, LOOP0 = 0
EGL = 1, ETS = 1 (limited long haul) EGL = 0, ETS = 1 (long haul)	EGL = 0, ETS = 0 (short haul) EGL = 1, ETS = 0 (long haul)
MM1 = 0, MM0 = 0	MM1 = 0, MM0 = 0
RT1 = 1, RT0 = 0 (internal Rx side, 100Ω enabled)	RT1 = 0, RT0 = 1 (internal Rx side, 120Ω enabled) RT1 = 1, RT0 = 1 (internal Rx side, 75Ω enabled)
JAMUX = 1, ETS = 1	JAMUX = 1, ETS = 0

The configuration settings of the DS2148 or the DS21348 in software mode are:

Software Mode Register Settings for T1		Software Mode Register Settings for E1
MCLK = 2.048MHz		MCLK = 2.048MHz
CCR1 (00H)	CCR1.7 = 1 CCR1.6 = 0 CCR1.3 = 1 CCR1.1 = 1	CCR1 (00H)	CCR1.7 = 0 CCR1.6 = 0 CCR1.3 = 1 CCR1.1 = 1
CCR2 (01H)	CCR2.3 = 1 CCR2.2 = 1 CCR2.1 = 0 CCR2.0 = 0	CCR2 (01H)	CCR2.3 = 1 CCR2.2 = 1 CCR2.1 = 0 CCR2.0 = 0
CCR4 (03H)	CCR4.7 = CCR4.6 = CCR4.5 = 0 CCR4.1 (application dependent) CCR4.0 = 0	CCR4 (03H)	CCR4.7, CCR4.6, and CCR4.5 (application dependent) CCR4.1 (application dependent) CCR4.0 = 0
CCR5 (04H)	CCR5.5 = 0, CCR5.4 = 0 CCR5.1 = 1, CCR5.0 = 0 (internal Rx side, 100Ω enabled)	CCR5 (04H)	CCR5.5 = 0, CCR5.4 = 0 CCR5.1 = 0, CCR5.0 = 1 (internal RX side, 120Ω enabled) CCR5.1 = 1, CCR5.0 = 1 (internal Rx side, 75Ω enabled)

Related Parts
DS21348	3.3V E1/T1/J1 Line Interface	Free Samples
DS2148	5V E1/T1/J1 Line Interface

Next Steps
EE-Mail	Subscribe to EE-Mail and receive automatic notice of new documents in your areas of interest.
Download	Download, PDF Format (32kB)
Share	Other Channels E-Mail this page to an associate or friend.

APP 387: May 29, 2002
APPLICATION NOTE 387, AN387, AN 387, APP387, Appnote387, Appnote 387

Other Channels

E-Mail

Download, PDF Format (32kB)

Related Parts/Samples

Sign-Up for EE-Mail™

Using DS2148/DS21348 as Repeater

Introduction

Share

More