DS90C032B
LVDS Quad CMOS Differential Line Receiver
DS90C032B LVDS Quad CMOS Differential Line Receiver
March 1999
General Description
The DS90C032B is a quad CMOS differential line receiver
designed for applications requiring ultra low power dissipation and high data rates. The device is designed to support
data rates in excess of 155.5 Mbps (77.7 MHz) utilizing Low
Voltage Differential Signaling (LVDS) technology.
The DS90C032B accepts low voltage (350 mV) differential
input signals andtranslatesthem to CMOS (TTL compatible)
output levels. The receiver supports a TRI-STATE
that may be used to multiplex outputs.The receiver also supports OPEN and terminated (100Ω) input Fail-safe. Receiver
output will be HIGH for both Fail-safe conditions.
The DS90C032B provides power-off high impedance LVDS
inputs. This feature assures minimal loading effect on the
LVDS bus lines when V
The DS90C032B and companion line driver (DS90C031B)
provide a new alternative to high power pseudo-ECLdevices
for high speed point-to-point interface applications.
is not present.
CC
®
function
Features
>
n
155.5 Mbps (77.7 MHz) switching rates
n Accepts small swing (350 mV) differential signal levels
n High Impedance LVDS inputs with power down
n Ultra low power dissipation
n 600 ps maximum differential skew (5V, 25˚C)
n 6.0 ns maximum propagation delay
n Industrial operating temperature range
n Available in surface mount packaging (SOIC)
n Pin compatible with DS26C32A, MB570 (PECL) and
41LF (PECL)
n Supports OPEN and terminated input fail-safe
n Conforms to ANSI/TIA/EIA-644 LVDS standard
Connection DiagramFunctional Diagram
Dual-In-Line
DS100990-1
Order Number
DS90C032BTM
See NS Package
Number M16A
DS100990-2
Receiver Truth Table
ENABLESINPUTSOUTPUT
ENEN
LHXZ
All other combinationsV
of ENABLE inputsV
TRI-STATE®is a registered trademark of National Semiconductor Corporation.
Supply Voltage (V
Input Voltage (R
Enable Input Voltage
(EN, EN
*
Output Voltage (R
Maximum Package Power Dissipation
)−0.3V to +6V
CC
)−0.3V to +5.8V
IN+,RIN−
)−0.3V to (VCC+ 0.3V)
)−0.3V to (VCC+ 0.3V)
OUT
@
+25˚C
M Package1025 mW
Derate M Package8.2 mW/˚C above +25˚C
Storage Temperature Range−65˚C to +150˚C
Lead Temperature Range
Soldering (4 sec.)+260˚C
Maximum Junction
Temperature+150˚C
Recommended Operating
Conditions
MinTypMaxUnits
Supply Voltage
)
(V
CC
Receiver Input
Voltage
Operating Free Air Temperature (T
DS90C032BT−40+25+85˚C
+4.5+5.0+5.5V
GND2.4V
)
A
Electrical Characteristics
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified. (Notes 2, 3)
SymbolParameterConditionsPinMinTypMaxUnits
V
V
I
V
V
I
I
V
V
I
V
I
I
Differential Input High Threshold VCM= +1.2VR
TH
Differential Input Low Threshold−100mV
TL
Input CurrentV
IN
Output High VoltageI
OH
Output Low VoltageI
OL
Output Short Circuit CurrentEnabled, V
OS
Output TRI-STATE CurrentDisabled, V
OZ
Input High VoltageEN,
IH
Input Low Voltage0.8V
IL
Input Current−10
I
Input Clamp VoltageI
CL
No Load Supply CurrentEN, EN
CC
Receivers EnabledEN, EN
No Load Supply Current
CCZ
Receivers Disabled
=
+2.4VV
IN
=
V
0V−10
IN
=
−0.4 mA, V
OH
=
I
−0.4 mA, Input terminated3.84.9V
OH
=
2 mA, V
OL
OUT
=
−18 mA−1.5−0.8V
CL
=
*
=
*
EN=GND, EN
=
5.5V or 0V−10
CC
=
+200 mVR
ID
=
−200 mV0.070.3V
ID
=
0V (Note 8)−15−60−100mA
=
0V or V
OUT
V
CC
CC
or GND, Inputs OpenV
2.4 or 0.5, Inputs Open3.711mA
=
*
, Inputs Open3.510mA
V
CC
,
IN+
R
IN−
3.84.9V
OUT
−10
2.0V
*
EN
CC
+100mV
±
1+10µA
±
1+10µA
±
1+10µA
±
1+10µA
3.510mA
www.national.com2
Switching Characteristics
=
V
+5.0V, T
CC
SymbolParameterConditionsMinTypMaxUnits
t
PHLD
t
PLHD
t
SKD
t
SK1
t
TLH
t
THL
t
PHZ
t
PLZ
t
PZH
t
PZL
=
+25˚C (Notes 3, 4, 9)
A
Differential Propagation Delay High to LowC
Differential Propagation Delay Low to HighV
Differential Skew |t
PHLD−tPLHD
|(
=
5 pF1.53.405.0ns
L
=
200 mV1.53.485.0ns
ID
Figure 1
and
Figure 2
)080600ps
Channel-to-Channel Skew (Note 5)00.61.0ns
Rise Time0.52.0ns
Fall Time0.52.0ns
Disable Time High to ZR
Disable Time Low to ZC
Enable Time Z to High(
=
2kΩ1015ns
L
=
10 pF1015ns
L
Figure 3
and
Figure 4
)410ns
Enable Time Z to Low410ns
Switching Characteristics
=
+5.0V
±
V
CC
SymbolParameterConditionsMinTypMaxUnits
t
t
t
t
t
t
t
t
t
t
t
Differential Propagation Delay High to LowC
PHLD
Differential Propagation Delay Low to HighV
PLHD
Differential Skew |t
SKD
Channel-to-Channel Skew (Note 5)00.61.5ns
SK1
Chip to Chip Skew (Note 6)5.0ns
SK2
Rise Time0.52.5ns
TLH
Fall Time0.52.5ns
THL
Disable Time High to ZR
PHZ
Disable Time Low to ZC
PLZ
Enable Time Z to High(
PZH
Enable Time Z to Low415ns
PZL
Note 1: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The table of “Electrical Characteristics” specifies conditions of device operation.
Note 2: Currentinto device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground unless otherwise specified.
Note 3: All typicals are given for: V
Note 4: Generator waveform for all tests unless otherwise specified: f=1 MHz, Z
Note 5: Channel-to-Channel Skew is defined as the difference between the propagation delay of one channel and that of the others on the same chip with an event
on the inputs.
Note 6: Chip to Chip Skew is defined as the difference between the minimum and maximum specified differential propagation delays.
Note 7: ESD Rating:
Note 8: Output short circuit current (I
ceed maximum junction temperature specification.
Note 9: C
includes probe and jig capacitance.
L
10%,T
=
−40˚C to +85˚C (Notes 3, 4, 9)
A
=
5 pF1.03.406.0ns
L
=
200 mV1.03.486.0ns
PHLD−tPLHD
CC
OS
|(
=
=
+5.0V, T
) is specified as magnitude only, minus sign indicates direction only. Only one output should be shorted at a time, do not ex-
+25˚C.
A
ID
Figure 1
and
Figure 2
)00.081.2ns
=
2kΩ1020ns
L
=
10 pF1020ns
L
Figure 3
and
Figure 4
)415ns
=
and tf(0%–100%) ≤ 1 ns for RINand trand tf≤ 6 ns for EN or EN*.
50Ω,t
O
r
Parameter Measurement Information
FIGURE 1. Receiver Propagation Delay and Transition Time Test Circuit
DS100990-3
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Parameter Measurement Information (Continued)
FIGURE 2. Receiver Propagation Delay and Transition Time Waveforms
DS100990-4
CLincludes load and test jig capacitance.
=
for t
and t
S
S
1
=
1
V
CC
GND for t
PZL
PZH
and t
PLZ
measurements.
measurements.
PHZ
DS100990-5
FIGURE 3. Receiver TRI-STATE Delay Test Circuit
DS100990-6
FIGURE 4. Receiver TRI-STATE Delay Waveforms
www.national.com4
Typical Application
FIGURE 5. Point-to-Point Application
Applications Information
LVDSdrivers and receivers are intended to be primarily used
in an uncomplicated point-to-point configuration as is shown
in
Figure 5.
vironment for the quick edge rates of the drivers. The receiver is connected to the driver through a balanced media
which may be 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 a voltage that is 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.
The DS90C032B differential line receiver is capable of detecting signals as low as 100 mV,over a
range centered around +1.2V.Thisis related to the driver offset voltage which is typically +1.2V.The driven signal is centered around this voltage and may shift
ter point. The
potential difference between the driver’s ground reference
and the receiver’s ground reference, the common-mode effects of coupled noise, or a combination of the two. Both receiver input pins should honor their specified operating input
voltage range of 0V to +2.4V (measured from each pin to
ground), exceeding these limits may turn on the ESD protection circuitry which will clamp the bus voltages.
Receiver Fail-Safe:
The LVDS receiver is a high gain, high speed device that
amplifies a small differential signal (20mV) to CMOS logic
This configuration provides a clean signaling en-
±
1V common-mode
±
±
1V shifting may be the result of a ground
1V around this cen-
DS100990-7
levels. Due to the high gain and tight threshold of the receiver,care should be taken to prevent noise from appearing
as a valid signal.
The receiver’s internal fail-safe circuitry is designed to
source/sink a small amount of current, providing fail-safe
protection (a stable known state of HIGH output voltage) for
floating or terminated receiver inputs.
1. Open Input Pins. The DS90C032B is a quad receiver
device, and if an application requires only 1, 2 or 3 receivers, the unused channel(s) inputs should be left
OPEN. Do not tie unused receiver inputs to ground or
any other voltages. The input is biased by internal high
value pull up and pull down resistors to set the output to
a HIGH state. This internal circuitry will guarantee a
HIGH, stable output state for open inputs.
2. Terminated Input. If the driver is disconnected (cable
unplugged), or if the driver is in a TRI-STATE or
power-off condition, the receiver output will again be in a
HIGH state, even with the end of cable 100Ω termination
resistor across the input pins. The unplugged cable can
become a floating antenna which can pick up noise. If
the cable picks up more than 10mV of differential noise,
the receiver may see the noise as a valid signal and
switch. To insure that any noise is seen as
common-mode and not differential, a balanced interconnect should be used. Twisted pair cable will offer better
balance than flat ribbon cable.
The footprint of the DS90C032B is the same as the industry
standard 26LS32 Quad Differential (RS-422) Receiver.
For additional LVDS application information, please refer to
National’s LVDS Owner’s Manual available through National’s website www.national.com/appinfo/lvds.
www.national.com5
Pin Descriptions
Pin
NameDescription
No.
2, 6,
10, 14
1, 7,
9, 15
3, 5,
11, 13
Non-inverting receiver input pin
R
IN+
Inverting receiver input pin
R
IN−
Receiver output pin
R
OUT
4ENActive high enable pin, OR-ed with
*
EN
Typical Performance Characteristics
Pin
NameDescription
No.
*
12EN
16V
Active low enable pin, OR-ed with EN
Power supply pin, +5V±10
CC
%
8GND Ground pin
Ordering Information
OperatingPackage Type/Order Number
TemperatureNumber
−40˚C to +85˚CSOP/M16ADS90C032BTM
Output High Voltage vs
Power Supply Voltage
Output Low Voltage vs
Power Supply Voltage
DS100990-8
Output High Voltage vs
Ambient Temperature
DS100990-9
Output Low Voltage vs
Ambient Temperature
DS100990-10
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DS100990-11
Typical Performance Characteristics (Continued)
Output Short Circuit Current
vs Power Supply Voltage
Differential Propagation Delay
vs Power Supply Voltage
DS100990-12
Output Short Circuit Current
vs Ambient Temperature
DS100990-13
Differential Propagation Delay
vs Ambient Temperature
DS90C032B LVDS Quad CMOS Differential Line Receiver
16-Lead (0.150" Wide) Molded Small Outline Package, JEDEC
Order Number DS90C032BTM
NS Package Number M16A
LIFE SUPPORT POLICY
NATIONAL’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 NATIONAL
SEMICONDUCTOR CORPORATION. As used herein:
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
whose failure to perform when properly used in
accordance with instructions for use provided in the
2. A critical component is 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.
labeling, can be reasonably expected to result in a
significant injury to the user.
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
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