SN74GTLPH1645
16-BIT LVTTL-TO-GTLP ADJUSTABLE-EDGE-RATE BUS TRANSCEIVER
www.ti.com
SCES290D–OCTOBER 1999–REVISED JUNE 2005
FEATURES
DGG OR DGV PACKAGE
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•
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Member of the Texas Instruments Widebus™
Family
(TOP VIEW)
1DIR
1A1
1A2
GND
1A3
1A4
1OE
1B1
1
2
3
4
5
6
7
8
9
56
55
TI-OPC™ Circuitry Limits Ringing on
Unevenly Loaded Backplanes
54 1B2
OEC™ Circuitry Improves Signal Integrity and
Reduces Electromagnetic Interference
GND
1B3
1B4
53
52
51
50
Bidirectional Interface Between GTLP Signal
Levels and LVTTL Logic Levels
V
CC
V
CC
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LVTTL Interfaces Are 5-V Tolerant
High-Drive GTLP Outputs (100 mA)
LVTTL Outputs (–24 mA/24 mA)
GND
1A5
49 GND
48 1B5
47 1B6
1A6 10
GND
1A7
1A8
GND
1B7
1B8
11
12
13
46
45
44
Variable Edge-Rate Control (ERC) Input
Selects GTLP Rise and Fall Times for Optimal
Data-Transfer Rate and Signal Integrity in
Distributed Loads
GND 14
ERC 15
2A1 16
2A2 17
43 BIAS V
CC
42
V
REF
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Ioff, Power-Up 3-State, and BIAS VCC Support
Live Insertion
41 2B1
40 2B2
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Bus Hold on A-Port Data Inputs
GND
GND
18
39
Distributed VCC and GND Pins Minimize
High-Speed Switching Noise
2A3 19
2A4 20
GND 21
38 2B3
37 2B4
36 GND
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Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
V
CC
22
35
V
CC
2A5 23
2A6 24
GND 25
2A7 26
2A8 27
2DIR 28
34 2B5
33 2B6
32 GND
31 2B7
30 2B8
29 2OE
DESCRIPTION/ORDERING INFORMATION
The SN74GTLPH1645 is a high-drive, 16-bit bus transceiver that provides LVTTL-to-GTLP and GTLP-to-LVTTL
signal-level translation. It is partitioned as two 8-bit transceivers. The device provides a high-speed interface
between cards operating at LVTTL logic levels and a backplane operating at GTLP signal levels. High-speed
(about three times faster than standard LVTTL or TTL) backplane operation is a direct result of GTLP's reduced
output swing (<1 V), reduced input threshold levels, improved differential input, OEC™ circuitry, and TI-OPC™
circuitry. Improved GTLP OEC and TI-OPC circuits minimize 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.
GTLP is the Texas Instruments derivative of the Gunning Transceiver Logic (GTL) JEDEC standard JESD 8-3.
The ac specification of the SN74GTLPH1645 is given only at the preferred higher noise-margin GTLP, but the
user has the flexibility of using this device at either GTL (VTT = 1.2 V and VREF = 0.8 V) or GTLP (VTT = 1.5 V and
VREF = 1 V) signal levels.
Normally, the B port operates at GTLP signal levels. The A-port and control inputs operate at LVTTL logic levels,
but are 5-V tolerant and are compatible with TTL and 5-V CMOS inputs. VREF is the B-port differential input
reference voltage.
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.
Widebus, TI-OPC, OEC are trademarks of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Copyright © 1999–2005, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.