Radiation-hardened design; total dose irradiation testing to
MIL-STD-883 Method 1019
- Total-dose: 100 krad(Si)
- Latchup immune (LET > 111 MeV-cm
2
/mg)
Packaging options:
- 16-lead flatpack (dual in-line)
Standard Microcircuit Drawing TBD
- QML Q and V compliant part
Compatible with IEEE 1596.3SCI LVDS
Compatible with ANSI/TIA/EIA 644-1996 LVDS
Standard
INTRODUCTION
The UT54LVDS031LV Quad Driver is a quad CMOS
differential line driver designed for applications requiring ultra
low power dissipation and high data rates. The device is
designed to support data rates in excess of 400.0 Mbps (200
MHz) utilizing Low Voltage Differential Signaling (LVDS)
technology.
The UT54LVDS031LV accepts TTL input levels and translates
them to low voltage (340mV) differential output signals. In
addition, the driver supports a three-state function that may be
used to disable the output stage, disabling the load current, and
thus dropping the device to an ultra low idle power state.
The UT54LVDS031LV and companion quad line receiver
UT54LVDS032LV provide new alternatives to high power
pseudo-ECL devices for high speed point-to-point interface
applications.
q
q
q
q
EL
O
D
IN1
D
IN2
D
EV
IN
EN
EN
D
IN3
D
IN4
Figure 1. UT54LVDS031LV Quad Driver Block Diagram
1
PM
D1
D2
D3
D4
EN
T
D
OUT1+
D
OUT1-
D
OUT2+
D
OUT2-
D
OUT3+
D
OUT3-
D
OUT4+
D
OUT4-
APPLICATIONS INFORMATION
The UT54LVDS031LV driver’s intended use is primarily in an
uncomplicated point-to-point configuration as is shown in
Figure 3. This configuration provides a clean signaling
environment for quick edge rates of the drivers. The receiver is
connected to the driver through a balanced media such as a
standard twisted pair cable, a parallel pair cable, or simply PCB
traces. Typically, the characteristic impedance of the media is
in the range of 100Ω. A termination resistor of 100Ω should be
selected to match the media and is located as close to the receiver
input pins as possible. The termination resistor converts the
current sourced by the driver into voltages that are detected by
the receiver. Other configurations are possible such as a multi-
receiver configuration, but the effects of a mid-stream
connector(s), cable stub(s), and other impedance discontinuities,
as well as ground shifting, noise margin limits, and total
termination loading must be taken into account.
D
IN1
D
OUT1+
D
OUT1-
EN
D
OUT2-
D
OUT2+
D
IN2
V
SS
1
2
3
4
5
6
7
8
UT54LVDS031LV
Driver
16
15
14
13
12
11
10
9
V
DD
D
IN4
D
OUT4+
D
OUT4-
EN
D
OUT3-
D
OUT3+
D
IN3
Figure 2. UT54LVDS031LV Pinout
ENABLE
EN
T
TRUTH TABLE
Enables
EN
L
EN
H
Input
D
IN
X
L
H
Z
L
H
Output
D
OUT+
D
OUT-
Z
H
L
DATA
INPUT
1/4 UT54LVDS032LV
+
-
DATA
OUTPUT
RT 100Ω
1/4 UT54LVDS031LV
PIN DESCRIPTION
Pin No.
1, 7, 9, 15
2, 6, 10, 14
3, 5, 11, 13
4
12
16
8
Name
D
IN
D
OUT+
D
OUT-
EN
EN
V
DD
V
SS
Description
Driver input pin, TTL/CMOS
compatible
Non-inverting driver output pin,
LVDS levels
IN
D
EV
Ground pin
Inverting driver output pin,
LVDS levels
Active high enable pin, OR-ed
with EN
Active low enable pin, OR-ed
with EN
Power supply pin, +3.3V + 0.3V
EL
O
2
PM
All other combinations
of ENABLE inputs
Figure 3. Point-to-Point Application
The UT54LVDS031LV differential line driver is a balanced
current source design. A current mode driver, has a high output
impedance and supplies a constant current for a range of loads
(a voltage mode driver on the other hand supplies a constant
voltage for a range of loads). Current is switched through the
load in one direction to produce a logic state and in the other
direction to produce the other logic state. The current mode
requires
(as discussed above) that a resistive termination be
employed to terminate the signal and to complete the loop as
shown in Figure 3. AC or unterminated configurations are not
allowed. The 3.4mA loop current will develop a differential
voltage of 340mV across the 100Ω termination resistor which
the receiver detects with a 240mV minimum differential noise
margin neglecting resistive line losses (driven signal minus
receiver threshold (340mV - 100mV = 240mV)). The signal is
centered around +1.2V (Driver Offset, V
OS
) with respect to
ground as shown in Figure 4.
Note:
The steady-state voltage
(V
SS
) peak-to-peak swing is twice the differential voltage (V
OD
)
and is typically 680mV.
3V
D
IN
D
OUT-
SINGLE-ENDED
D
OUT+
V
0D
0V
V
OH
V
OS
V
OL
+V
OD
0V (DIFF.)
0V
-V
OD
D
OUT+
- D
OUT-
DIFFERENTIAL OUTPUT
Note: The footprint of the UT54LVDS031LV is the same as the
industry standard Quad Differential (RS-422) Driver.
V
SS
The current mode driver provides substantial benefits over
voltage mode drivers, such as an RS-422 driver. Its quiescent
current remains relatively flat versus switching frequency.
Whereas the RS-422 voltage mode driver increases
exponentially in most cases between 20 MHz - 50 MHz. This
is due to the overlap current that flows between the rails of
the device when the internal gates switch. Whereas the
current mode driver switches a fixed current between its
output without any substantial overlap current. This is similar
to some ECL and PECL devices, but without the heavy static
I
CC
requirements of the ECL/PECL design. LVDS requires
80% less current than similar PECL devices. AC
specifications for the driver are a tenfold improvement over
other existing RS-422 drivers.
The Three-State function allows the driver outputs to be
disabled, thus obtaining an even lower power state when the
transmission of data is not required.
Figure 4. Driver Output Levels
IN
D
EV
3
EL
O
PM
EN
T
ABSOLUTE MAXIMUM RATINGS
1
(Referenced to V
SS
)
SYMBOL
V
DD
V
I/O
T
STG
P
D
T
J
Θ
JC
I
I
PARAMETER
DC supply voltage
Voltage on any pin
Storage temperature
Maximum power dissipation
Maximum junction temperature
2
Thermal resistance, junction-to-case
3
DC input current
LIMITS
-0.3 to 4.0V
-0.3 to (V
DD
+ 0.3V)
-65 to +150°C
1.25 W
+150°C
10°C/W
±
10mA
RECOMMENDED OPERATING CONDITIONS
SYMBOL
V
DD
T
C
V
IN
PARAMETER
Positive supply voltage
EN
T
Notes:
1. Stresses outside the listed absolute maximum ratings may cause permanent damage to the device. This is a stress rating only, and functional operation of the device
at these or any other conditions beyond limits indicated in the operational sections of this specification is not recommended. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability and performance.
2. Maximum junction temperature may be increased to +175°C during burn-in and life test.
3. Test per MIL-STD-883, Method 1012.
LIMITS
3.0 to 3.6V
Case temperature range
DC input voltage
PM
4
-55 to +125°C
0V to V
DD
IN
D
EV
EL
O
DC ELECTRICAL CHARACTERISTICS
1, 2
(V
DD
= 3.3V + 0.3V; -55°C < T
C
< +125°C)
SYMBOL
V
IH
V
IL
V
OL
V
OH
I
IN4
V
OD1
∆V
OD1
V
OS
∆V
OS
V
CL3
I
OS3
I
OZ4
I
CCL4
I
CCZ4
PARAMETER
High-level input voltage
Low-level input voltage
Low-level output voltage
High-level output voltage
Input leakage current
Differential Output Voltage
Change in Magnitude of V
OD
for
Complementary Output States
Offset Voltage
(TTL)
(TTL)
R
L
= 100Ω
R
L
= 100Ω
V
IN
= V
DD
R
L
= 100Ω
(figure 5)
R
L
= 100Ω
(figure 5)
R
L
= 100Ω,
Vos = Voh + Vol
--------------------------
-
2
R
L
= 100Ω
(figure 5)
I
CL
= -18mA
V
OUT
= 0V
2
EN = 0.8V and EN = 2.0 V,
V
OUT
= 0V or V
DD
1.125
-10
250
CONDITION
MIN
2.0
V
SS
0.90
1.60
+10
400
35
1.375
MAX
V
DD
0.8
UNIT
V
V
V
V
µA
mV
mV
V
Input clamp voltage
Output Short Circuit Current
Output Three-State Current
EN
T
-10
Change in Magnitude of V
OS
for
Complementary Output States
25
-1.5
9.0
+10
mV
V
mA
µΑ
O
Loaded supply current drivers
enabled
Loaded supply current drivers
disabled
R
L
= 100Ω all channels
PM
mA
30.0
mA
8.0
V
IN
= V
DD
or V
SS
(all inputs)
D
IN
= V
DD
or V
SS
Notes:
1. Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except differential voltages.
2. Output short circuit current (I
OS
) is specified as magnitude only, minus sign indicates direction only.
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