Texas Instruments SN74GTL16923DGGR Datasheet
SN54GTL16923, SN74GTL16923
18-BIT LVTTL-TO-GTL/GTL+ BUS TRANSCEIVERS
SCBS674E – AUGUST 1996 – REVISED NOVEMBER 1999
D
Members of the Texas Instruments
Widebus
D
D-Type Flip-Flops With Qualified Storage
Family
Enable
D
Translate Between GTL/GTL+ Signal Levels
and LVTTL Logic Levels
D
Support Mixed-Mode Signal Operation on
All Ports (5-V Input/Output Voltages With
3.3-V VCC)
D
I
Supports Partial-Power-Down-Mode
off
Operation
D
Bus Hold on Data Inputs Eliminates the
Need for External Pullup/Pulldown
Resistors on A Port
description
The ’GTL16923 devices are 18-bit registered bus transceivers that provide LVTTL-to-GTL/GTL+ and
GTL/GTL+-to-LVTTL signal-level translation. They are partitioned as two 9-bit transceivers with individual
output-enable controls and contain D-type flip-flops for temporary storage of data flowing in either direction. The
devices provide an interface between cards operating at LVTTL logic levels and a backplane operating at
GTL/GTL+ signal levels. Higher-speed operation is a direct result of the reduced output swing (<1 V), reduced
input threshold levels, and output edge control (OEC).
D
Distributed VCC and GND-Pin Configuration
Minimizes High-Speed Switching Noise
D
ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
D
Latch-Up Performance Exceeds 250 mA Per
JESD 17
D
Package Options Include Plastic Thin
Shrink Small-Outline (DGG) and Ceramic
Quad Flat (HV) Packages
The user has the flexibility of using these devices at either GTL (V
higher noise margin GTL+ (VTT = 1.5 V and V
= 1 V) signal levels. GTL+ is the T exas Instruments derivative
REF
= 1.2 V and V
TT
= 0.8 V) or the preferred
REF
of the Gunning transceiver logic (GTL) JEDEC standard JESD 8-3. The B port normally operates at GTL or
GTL+ signal levels, while the A-port and control inputs are compatible with LVTTL logic levels. All inputs can
be driven from either 3.3-V or 5-V devices which allows use in a mixed 3.3-V/5-V system environment. V
REF
is the reference input voltage for the B port.
Data flow in each direction is controlled by the output-enable (OEAB
and OEBA) and clock (CLKAB and CLKBA)
inputs. The clock-enable (CEAB and CEBA) inputs are used to enable or disable the clock for all 18 bits at a
time. However, OEAB
and OEBA are designed to control each 9-bit transceiver independently, which makes
the device more versatile.
For A-to-B data flow, the device operates on the low-to-high transition of CLKAB if CEAB
is low. When OEAB
is low, the outputs are active. When OEAB is high, the outputs are in the high-impedance state. Data flow for
B to A is similar to that of A to B but uses OEBA, CLKBA, and CEBA.
These devices are fully specified for partial-power-down applications using I
. The I
off
circuitry disables the
off
outputs, preventing damaging current backflow through the devices when they are powered down.
Active bus-hold circuitry holds unused or undriven L VTTL inputs at a valid logic state. Use of pullup or pulldown
resistors with the bus-hold circuitry is not recommended.
T o ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54GTL16923 is characterized for operation over the full military temperature range of –55°C to 125°C.
The SN74GTL16923 is characterized for operation from –40°C to 85°C.
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 and OEC are trademarks of Texas Instruments Incorporated.
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 1999, Texas Instruments Incorporated
1
SN54GTL16923, SN74GTL16923
MODE
Latched storage of A data
Clocked storage of A data
18-BIT LVTTL-TO-GTL/GTL+ BUS TRANSCEIVERS
SCBS674E – AUGUST 1996 – REVISED NOVEMBER 1999
SN74GTL16923 . . . DGG PACKAGE
CEAB
CEBA
1A1
GND
1A2
1A3
GND
V
CC
1A4
GND
1A5
1A6
GND
1A7
1A8
GND
1A9
2A1
GND
2A2
2A3
GND
2A4
2A5
GND
2A6
V
CC
GND
2A7
2A8
GND
2A9
(TOP VIEW)
1
64
2
63
3
62
4
61
5
60
6
59
7
58
8
57
9
56
10
55
11
54
12
53
13
52
14
51
15
50
16
49
17
48
18
47
19
46
20
45
21
44
22
43
23
42
24
41
25
40
26
39
27
38
28
37
29
36
30
35
31
34
32
33
CLKAB
1OEAB
1OEBA
1B1
GND
1B2
1B3
V
CC
1B4
1B5
1B6
GND
1B7
1B8
GND
1B9
2B1
GND
2B2
2B3
GND
2B4
2B5
2B6
V
REF
2B7
2B8
GND
2B9
2OEBA
2OEAB
CLKBA
SN54GTL16923 . . . HV PACKAGE
CC
1A4
GND
1A3
V
9876543216867666564636261
GND
GND
GND
GND
GND
10
11
1A5
12
1A6
13
GND
14
1A7
15
1A8
16
17
1A9
18
NC
19
2A1
20
21
2A2
22
2A3
23
24
2A4
25
2A5
26
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
CC
V
2A6
NC – No internal connection
GND
2A7
1A2
2A8
GND
GND
(TOP VIEW)
NC
CEAB
1A1
NC
2A9
CEBA
CLKAB
1OEAB
2OEAB
CLKBA
1OEBA
1B1
2B9
2OEBA
GND
GND
1B2
2B8
1B3
2B7
V
CC
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
V
1B4
1B5
1B6
GND
1B7
1B8
GND
1B9
NC
2B1
GND
2B2
2B3
GND
2B4
2B5
2B6
REF
2
OUTPUT
B
‡
0
‡
0
†
, CLKBA,
FUNCTION TABLE
INPUTS
CEAB OEAB CLKAB A
X H X X Z Isolation
H L X X B
X L H or L X B
L L ↑ L L
L L ↑ H H
†
A-to-B data flow is shown. B-to-A data flow is similar, but uses OEBA
and CEBA
‡
Output level before the indicated steady-state input conditions were established
.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic diagram (positive logic)
SN54GTL16923, SN74GTL16923
18-BIT LVTTL-TO-GTL/GTL+ BUS TRANSCEIVERS
SCBS674E – AUGUST 1996 – REVISED NOVEMBER 1999
V
REF
1OEAB
CEAB
CLKAB
CLKBA
CEBA
1OEBA
1A1
40
63
1
64
33
32
62
2
CLK
CE
1D
CE
1D
CLK
61
1B1
2A1
34
35
17
2OEAB
2OEBA
Pin numbers shown are for the DGG package.
CLK
CE
1D
To Eight Other Channels
CE
1D
CLK
To Eight Other Channels
48
2B1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
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