SN74GTLP21395
TWO 1-BIT LVTTL-TO-GTLP ADJUSTABLE-EDGE-RATE BUS TRANSCEIVERS
WITH SPLIT LVTTL PORT, FEEDBACK PATH, AND SELECTABLE POLARITY
SCES350C – JUNE 2001 – REVISED NOVEMBER 2001
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TI-OPC Circuitry Limits Ringing on
Unevenly Loaded Backplanes
OEC Circuitry Improves Signal Integrity
and Reduces Electromagnetic Interference
Bidirectional Interface Between GTLP
Signal Levels and LVTTL Logic Levels
Split LVTTL Port Provides a Feedback Path
for Control and Diagnostics Monitoring
Y Outputs Have Equivalent 26-Ω Series
Resistors, So No External Resistors Are
Required
LVTTL Interfaces Are 5-V Tolerant
High-Drive GTLP Outputs (100 mA)
LVTTL Outputs (–12 mA/12 mA)
Variable Edge-Rate Control (ERC) Input
Selects GTLP Rise and Fall Times for
Optimal Data-Transfer Rate and Signal
Integrity in Distributed Loads
I
off
, Power-Up 3-State, and BIAS V
CC
Support Live Insertion
Polarity Control Selects True or
Complementary Outputs
Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
DGV, DW, OR PW PACKAGE
(TOP VIEW)
1Y
1T/C
2Y
GND
1OEAB
V
CC
1A
GND
2A
2OEAB
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
1OEBY
2T/C
2OEBY
GND
1B
ERC
2B
GND
V
REF
BIAS V
CC
description
The SN74GTLP21395 is two 1-bit, high-drive, 3-wire bus transceivers that provide LVTTL-to-GTLP and
GTLP-to-LVTTL signal-level translation for applications, such as primary and secondary clocks, that require
individual output-enable and true/complement controls. The device allows for transparent and inverted
transparent modes of data transfer with separate LVTTL input and LVTTL output pins, which provide a feedback
path for control and diagnostics monitoring. The device provides a high-speed interface between cards
operating at LVTTL logic levels and a backplane operating at GTLP signal levels and is designed especially to
work with the Texas Instruments 3.3-V 1394 backplane physical-layer controller. High-speed (about three times
faster than standard LVTTL or TTL) backplane operation is a direct result of GTLP reduced output swing (<1 V),
reduced input threshold levels, improved differential input, OEC circuitry, and TI-OPC circuitry. Improved
GTLP OEC and TI-OPC circuitry minimizes bus settling time, and have been designed and tested using several
backplane models. The high drive allows incident-wave switching in heavily loaded backplanes, with equivalent
load impedance down to 11
Ω.
The Y outputs, which are designed to sink up to 12 mA, include equivalent 26-Ω resistors to reduce overshoot
and undershoot.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
OEC and TI-OPC are trademarks of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright
2001, Texas Instruments Incorporated
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
1
TI [ TEXAS INSTRUMENTS ]
