AN1672 Datasheet, PDF (3/10 Pages) ON Semiconductor – The ECL Translator Guide

AN1672/D
Section 1: Translation Between Differently Supplied ECL Drivers and Receivers
Table 3. Translation Between Differently Supplied ECL Drivers and Receivers
From:
To:
PECL
V_CC = +5 V
LVPECL
V_CC = +3.3 V
LVNECL
V_EE = −3.3 V
PECL
V_CC = +5 V
LVPECL
V_CC = +3.3 V
Standard Connection
LVEL92
EL17
EP17
LVEL16
LVEL17
Direct Connection
LVEL91
LVEL91
LVEP91
LVNECL
V_EE = −3.3 V
NECL
V_EE = −4.5 V to −5.2 V
EL90
EL90
LVEL90
LVEL90
Standard Connection
Standard Connection
NECL
V_EE = −4.5 to −5.2 V
EL91
LVEP91
Direct Connection
Standard Connection
From PECL to LVPECL
The MC100LVEL92 translates signals from a PECL
(V_CC = 5.0, V_EE = 0.0) operating mode driver to a LVPECL
V_CC = 3.3, V_EE = 0.0 operating mode receiver.
From PECL to NECL
The MC100EL91 translates signals from a PECL
(V_CC = 5.0, V_EE = 0.0) operating mode driver to a NECL
(V_CC = 0.0, V_EE = −5.0) operating mode receiver.
From PECL to LVNECL
The MC100LVEL91 translates signals from a PECL
(V_CC = 5.0, V_EE = 0.0) operating mode driver to a LVNECL
(V_CC = 0.0, V_EE = −3.3) operating mode receiver.
From LVPECL to PECL
The critical parameter for differential PECL receiver to
properly interface with a differential LVPECL driver is
V_IHCMRmin (or V_CMRmin). V_IH and V_IL limits may be
disregarded for differential receiving. Assuming no tangent
loss from traces, if the LVPECL driver V_OHmin level is more
positive (higher) than the V_IHCMRmin spec of the differential
PECL receiver, the device will properly translate or level
shift from LVPECL to PECL. For example, suppose a
MC100EP16 operating differentially in LVPECL mode
(V_CC = 3.3, V_EE = 0.0) with a worst case V_OHmin of 2.155 V,
drives a MC100EP17 receiver differentially operating in
PECL mode (V_CC = 5.0, V_EE = 0.0). The MC100EP17
receiver spec V_IHCMRmin is 2.0 V and will always properly
recognize the drivers HIGH level 2.155 V (or higher). The
MC100EL13, MC100EL14, MC100EL29, MC100EL56
are also acceptable as LVPECL receivers differentially.
Most of the “E” (ECLinPS), “EL” (ECLinPS Lite),
10H/100H, or 10xxx series devices do not have a
sufficiently low V_IHCMRmin to receive LVPECL.
When a receiver in LVPECL mode is driven single ended,
the critical parameters will be V_IL and V_IH. V_IHCMRmin (or
V_CMRmin) may be ignored. A PECL receiver V_ILmin,
typically >3.0 V, will be insufficiently low to recognize the
drivers HIGH level and will not permit proper interconnect.
From LVPECL to LVNECL
The MC100LVEL91 translates signals from a PECL
(V_CC = 5.0, V_EE = 0.0) operating mode driver to a
LVNECL (V_CC = 0.0, V_EE = −3.3) operating mode receiver.
From LVPECL to NECL
The MC100EL91 translates signals from a LVPECL
(V_CC = 3.3, V_EE = 0.0) operating mode driver to a NECL
(V_CC = 0.0, V_EE = −5.0) operating mode receiver.
From LVNECL to PECL
The MC100EL90 translates signals from a LVNECL
(V_CC = 0.0, V_EE = −3.3) operating mode driver to a PECL
(V_CC = 5.0, V_EE = 0.0) operating mode receiver.
From LVNECL to LVPECL
The MC100LVEL90 translates signals from a LVNECL
(V_CC = 0.0, V_EE = −3.3) operating mode driver to a PECL
(V_CC = 3.3, V_EE = 0.0) operating mode receiver.
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