FAIRCHILD GTLP18T612

Revised September 1999
GTLP18T612
18-Bit LVTTL/GTLP Universal Bus Transceiver
General Description
Features
The GTLP18T612 is an 18-bit universal bus transceiver
which provides LVTTL to GTLP signal level translation. It
allows for transparent, latched and clocked modes of data
transfer. The device provides a high speed interface for
cards operating at LVTTL logic levels and a backplane
operating at GTLP logic levels. High speed backplane
operation is a direct result of GTLP’s reduced output swing
(< 1V), reduced input threshold levels and output edge rate
control. The edge rate control minimizes bus settling time.
GTLP is a Fairchild Semiconductor derivative of the Gunning Transistor logic (GTL) JEDEC standard JESD8-3.
■ Bidirectional interface between GTLP and LVTTL logic
levels
Fairchild's GTLP has internal edge-rate control and is Process, Voltage, and Temperature (PVT) compensated. Its
function is similar to BTL or GTL but with different output
levels and receiver thresholds. GTLP output LOW level is
less than 0.5V, the output HIGH is 1.5V and the receiver
threshold is 1.0V.
■ Edge Rate Control to minimize noise on the GTLP port
■ Power up/down high impedance for live insertion
■ External VREF pin for receiver threshold
■ BiCMOS technology for low power dissipation
■ Bushold data inputs on A Port eliminates the need for
external pull-up resistors for unused inputs
■ LVTTL compatible Driver and Control inputs
■ Flow-through architecture optimizes PCB layout
■ Open drain on GTLP to support wired-or connection
■ A-Port source/sink −24 mA/+24 mA
■ B-Port sink capability +50 mA
■ D-type flip-flop, latch and transparent data paths
Ordering Code:
Order Number
Package Number
Package Description
GTLP18T612MEA
MS56A
56-Lead Shrink Small Outline Package (SSOP), JEDEC MO-118, 0.300” Wide
GTLP18T612MTD
MTD56
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
© 1999 Fairchild Semiconductor Corporation
DS500169
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GTLP18T612 18-Bit LVTTL/GTLP Universal Bus Transceiver
May 1999
GTLP18T612
Pin Descriptions
Connection Diagram
Pin Names Description
OEAB
A-to-B Output Enable
(Active LOW) (LVTTL Level)
OEBA
B-to-A Output Enable
(Active LOW) (LVTTL Level)
CEAB
A-to-B Clock/LE Enable
(Active LOW) (LVTTL Level)
CEBA
B-to-A Clock/LE Enable
(Active LOW) (LVTTL Level)
LEAB
A-to-B Latch Enable
(Transparent HIGH) (LVTTL Level)
LEBA
B-to-A Latch Enable
(Transparent HIGH) (LVTTL Level)
VREF
GTLP Input Threshold
Reference Voltage
CLKAB
A-to-B Clock (LVTTL Level)
CLKBA
B-to-A Clock (LVTTL Level)
A1–A18
A-to-B Data Inputs or
B-to-A 3-STATE Outputs
B1–B18
B-to-A Data Inputs or
A-to-B Open Drain Outputs
Functional Description
The GTLP18T612 is an 18 bit registered transceiver containing D-type flip-flop, latch and transparent modes of operation
for the data path. Data flow in each direction is controlled by the clock enables (CEAB and CEBA), latch enables (LEAB
and LEBA), clock (CLKAB and CLKBA) and output enables (OEAB and OEBA). The clock enables (CEAB and CEBA) and
the output enables (OEAB and OEBA) control the 18 bits of data for the A-to-B and B-to-A directions respectively.
For A-to-B data flow, when CEAB is LOW, the device operates on the LOW-to-HIGH transition of CLKAB for the flip-flop
and on the HIGH-to-LOW transition of LEAB for the latch path. That is, if CEAB is LOW and LEAB is LOW the A data is
latched regardless as to the state of CLKAB (HIGH or LOW) and if LEAB is HIGH the device is in transparent mode. When
OEAB is LOW the outputs are active. When OEAB is HIGH the outputs are HIGH impedance. The data flow of B-to-A is
similar except that CEBA, OEBA, LEBA, and CLKBA are used.
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Inputs
Output
B
Mode
Latched
CEAB
OEAB
LEAB
CLKAB
A
X
H
X
X
X
Z
L
L
L
H or L
X
B0 (Note 2)
storage
L
L
L
H or L
X
B0 (Note 3)
of A data
X
L
H
X
L
L
Transparent
X
L
H
X
H
H
L
L
L
↑
L
L
Clocked
L
L
L
↑
H
H
storage
H
L
L
X
X
B0 (Note 3)
Clock inhibit
of A data
Note 1: A-to-B data flow is shown. B-to-A data flow is similar but uses OEBA, LEBA, CLKBA, and CEBA.
Note 2: Output level before the indicated steady state input conditions were established, provided that CLKAB was HIGH before LEAB went LOW.
Note 3: Output level before the indicated steady-state input conditions were established.
Logic Diagram
3
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GTLP18T612
Truth Table (Note 1)
GTLP18T612
Absolute Maximum Ratings(Note 4)
Supply Voltage (VCC )
−0.5V to +4.6V
DC Input Voltage (VI)
−0.5V to +4.6V
Recommended Operating
Conditions (Note 6)
Supply Voltage VCC /VCCQ
DC Output Voltage (VO)
3.15V to 3.45V
Bus Termination Voltage (VTT)
−0.5V to +4.6V
Outputs 3-STATE
−0.5V to VCC + 0.5V
Outputs Active (Note 5)
DC Output Sink Current into
GTLP
1.47V to 1.53V
VREF
0.98V to 1.02V
Input Voltage (VI)
48 mA
A Port IOL
DC Output Source Current from
A Port IOH
on A Port and Control Pins
0.0V to 3.45V
on B Port
0.0V to 3.45V
−48 mA
HIGH Level Output Current (IOH)
100 mA
LOW Level Output Current (IOL)
DC Output Sink Current into
−24 mA
A Port
B Port in the LOW State, IOL
DC Input Diode Current (IIK)
+24 mA
A Port
VI < 0V
−50 mA
+50 mA
B Port
DC Output Diode Current (IOK)
−40°C to +85°C
Operating Temperature (TA)
VO < 0V
−50 mA
VO > VCC
+50 mA
Note 4: Absolute Maximum continuous ratings are those values beyond
which damage to the device may occur. Exposure to these conditions or
conditions beyond those indicated may adversely affect device reliability.
Functional operation under absolute maximum rated conditions in not
implied.
>2000V
ESD Performance
−65°C to +150°C
Storage Temperature (TSTG)
Note 5: IO Absolute Maximum Rating must be observed.
Note 6: Unused inputs must be held HIGH or LOW.
DC Electrical Characteristics
Over Recommended Operating Free-Air Temperature Range, VREF = 1.0V (unless otherwise noted).
Symbol
VIH
VIL
Test Conditions
Min
B Port
VREF +0.05
Others
2.0
B Port
0.0
Typ
(Note 7)
VTT
VREF − 0.05
Others
VREF
VOL
1.0
GTL
0.8
A Port
A Port
B Port
II
0.8
GTLP (Note 8)
VIK
VOH
VCC = 3.15V
II = −18 mA
VCC, VCCQ = Min to Max (Note 9)
IOH = −100 µA
VCC = 3.15V
IOH = −8 mA
2.4
IOH = -24mA
2.0
IOL = 100 µA
0.2
0.5
VCC = 3.15V
IOL = 40 mA
0.40
IOL = 50 mA
0.55
Control Pins
VCC = Min to Max (Note 9)
VI = 3.45V or 0V
±5
VCC = 3.45V
VI = 0V
−10
VI = 3.45
10
A Port and Control Pins VCC = 0
A Port
A Port
VCC = 3.45V
VCC = 3.45V
B Port
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5
VI = 0
−5
VI = 0.8V
B Port
A Port
VI = VCC
VI or VO = 0 to 3.45V
VCC = 3.15V
4
V
V
V
IOL = 24mA
IOFF
IOZL
−1.2
VCC, VCCQ = Min to Max (Note 9)
II(hold)
V
VCC –0.2
VCC = 3.15V
VCC = 3.45V
Units
V
A Port
B Port
IOZH
Max
30
75
VI = 2.0V
−75
VO = 3.45
10
VO = 1.5V
5
VO = 0V
−10
VO = 0.55V
−5
V
V
µA
µA
µA
µA
µA
µA
µA
Symbol
ICC
(Continued)
Test Conditions
A or B Ports
(VCC/VCCQ)
Max
(Note 7)
VCC = 3.45V
Outputs HIGH
30
IO = 0
Outputs LOW
30
40
VI = VCC or GND
Outputs Disabled
30
45
One Input at 2.7V
0
2
∆ICC
A Port and
VCC = 3.45V,
(Note 10)
Control Pins
A or Control Inputs at VCC or GND
Ci
Typ
Min
Control Pins
VI = VCC or 0
6
A Port
VI = VCC or 0
7.5
B Port
VI = VCC or 0
9.0
Units
40
mA
mA
pF
Note 7: All typical values are at VCC = 3.3V, VCCQ = 3.3V, and TA = 25°C.
Note 8: GTLP VREF and VTT are specified to 2% tolerance since signal integrity and noise margin can be significantly degraded if these supplies are noisy. In
addition, VTT and Rterm can be adjusted beyond the recommended operating conditions to accommodate backplane impedances other than 50Ω, but must
remain within the boundaries of the DC Absolute Maximum ratings. Similarly VREF can be adjusted to optimize noise margin.
Note 9: For conditions shown as Min or Max, use the appropriate value specified under recommended operating conditions.
Note 10: This is the increase in supply current for each input that is at the specified TTL voltage level rather than VCC or GND.
AC Operating Requirements
Over recommended ranges of supply voltage and operating free-air temperature, VREF = 1.0V (unless otherwise noted).
Symbol
fCLOCK
Maximum Clock Frequency
tWIDTH
Pulse Duration
tSU
tHOLD
Setup Time
Hold Time
Test Conditions
Min
Max
Unit
0
175
MHz
LEAB or LEBA HIGH
3.0
CLKAB or CLKBA HIGH or LOW
3.0
A before CLKAB↑
1.1
B before CLKBA↑
3.0
A before LEAB
1.1
B before LEBA
2.7
CEAB before CLKAB↑
1.2
CEBA before CLKBA↑
1.4
A after CLKAB↑
0.0
B after CLKBA↑
0.0
A after LEAB
0.8
B after LEBA
0.0
CEAB after CLKAB↑
1.0
CEBA after CLKBA↑
1.9
5
ns
ns
ns
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GTLP18T612
DC Electrical Characteristics
GTLP18T612
AC Electrical Characteristics
Over recommended range of supply voltage and operating free-air temperature, VREF = 1.0V (unless otherwise noted).
CL = 30 pF for B Port and CL = 50 pF for A Port.
Symbol
tPLH
From
To
(Input)
(Output)
A
B
tPHL
tPLH
LEAB
B
tPHL
CLKAB
tPLH
B
tPHL
tPLH
OEAB
B
tPHL
Min
Typ
(Note 11)
2.1
4.1
6.3
1.0
2.7
4.4
2.2
4.2
6.3
1.0
2.4
4.2
2.2
4.4
6.5
1.0
2.5
4.4
2.0
3.8
5.6
1.0
2.6
4.3
tRISE
Transition time, B outputs (20% to 80%)
3.1
tFALL
Transition time, B outputs (20% to 80%)
2.1
B
tPLH
A
tPHL
tPLH
LEBA
A
tPHL
tPLH
CLKBA
A
tPHL
tPZH, tPZL
OEBA
A
tPHZ, tPLZ
Max
Unit
ns
ns
ns
ns
ns
1.8
3.8
5.8
1.8
3.8
5.8
0.3
2.2
4.6
0.4
2.4
4.6
0.5
2.4
4.6
0.6
2.6
4.6
0.3
2.7
5.2
0.3
2.5
5.2
ns
ns
ns
ns
Note 11: All typical values are at VCC = 3.3V, and TA = 25°C.
Extended Electrical Characteristics
Over recommended ranges of supply voltage and operating free-air temperature VREF = 1.0V (unless otherwise noted).
CL = 30 pF for B Port and CL = 50 pF for A Port.
Symbol
tOSLH (Note 12)
From
(Input)
To
(Output)
A
B
Min
tOSHL (Note 12)
tPV(HL) (Note 13)(Note 14)
Typ
(Note 11)
Max
Unit
0.8
1.0
ns
0.3
0.5
ns
A
B
CLKAB
B
CLKAB
B
B
A
0.7
tOST (Note 12)
B
A
tPV (Note 13)
B
A
CLKAB
A
tOSLH (Note 12)
tOSHL (Note 12)
tPV(HL) (Note 13)(Note 14)
tOSLH (Note 12)
tOSHL (Note 12)
tOSLH (Note 12)
tOSHL (Note 12)
tOST (Note 12)
CLKAB
A
tPV (Note 13)
CLKAB
A
0.8
ns
0.9
1.0
ns
0.3
0.5
ns
0.8
ns
1.0
ns
0.6
1.0
ns
0.7
1.1
ns
1.5
ns
0.5
1.0
ns
0.6
1.0
ns
1.1
1.2
ns
1.5
ns
Note 12: tOSHL/tOSLH and tOST - Output to output skew is defined as the absolute value of the difference between the actual propagation delay for all outputs
within the same packaged device. The specifications are given for specific worst case VCC and temperature and apply to any outputs switching in the same
direction either HIGH-to-LOW (tOSHL) or LOW-to-HIGH (tOSLH) or in opposite directions both HL and LH (tOST). This parameter is guaranteed by design and
statistical process distribution. Actual skew values between the GTLP outputs could vary on the backplane due to the loading and impedance seen by the
device.
Note 13: tPV - Part to part skew is defined as the absolute value of the difference between the actual propagation delay for all outputs from device to device.
The parameter is specified for a specific worst case VCC and temperature. This parameter is guaranteed by design and statistical process distribution. Actual
skew values between the GTLP outputs could vary on the backplane due to the loading and impedance seen by the device.
Note 14: Due to the open drain structure on GTLP outputs tOST and t PV(LH) in the A-to-B direction are not specified. Skew on these paths is dependent on the
VTT and RT values on the backplane.
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6
Test Circuit for A Outputs
Test
Test Circuit for B Outputs
S
tPLH/tPHL Open
tPLZ/tPZL
6V
Note B: For B Port, CL = 30 pF is used for worst case.
tPHZ/tPZH GND
Note A: CL includes probes and Jig capacitance.
Voltage Waveform - Propagation Delay Times
Voltage Waveform - Setup and Hold Times
Voltage Waveform - Pulse Width
Voltage Waveform - Enable and Disable times
Output Waveform 1 is for an output with internal conditions such that the
output is LOW except when disabled by the control output.
Output Waveform 2 is for an output with internal conditions such that the
output is HIGH except when disabled by the control output.
Input and Measure Conditions
A or LVTTL
Pins
B or GTLP
Pins
VinHIGH
3.0
1.5
VinLOW
0.0
0.0
VM
1.5
1.0
VX
VOL + 0.3V
N/A
VY
VOH − 0.3V
N/A
All input pulses have the following characteristics: Frequency = 10MHz, tRISE = tFALL = 2 ns (10% to 90%), Z O = 50Ω.
The outputs are measured one at a time with one transition per measurement.
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GTLP18T612
Test Circuits and Timing Waveforms
GTLP18T612
Physical Dimensions inches (millimeters) unless otherwise noted
56-Lead Shrink Small Outline Package (SSOP), JEDEC MO-118, 0.300” Wide
Package Number MS56A
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GTLP18T612 18-Bit LVTTL/GTLP Universal Bus Transceiver
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Package Number MTD56
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
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FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
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