DS91M125
DS91M125 125 MHz 1:4 M-LVDS Repeater with LVDS Input
Literature Number: SNLS290B
DS91M125
November 9, 2009
125 MHz 1:4 M-LVDS Repeater with LVDS Input
General Description
The DS91M125 is a 1:4 M-LVDS repeater designed for driv-
ing and distributing clock or data signals to up to four multi-
point networks.
M-LVDS (Multipoint LVDS) is a new family of bus interface
devices based on LVDS technology specifically designed for
multipoint and multidrop cable and backplane applications. It
differs from standard LVDS in providing increased drive cur-
rent to handle double terminations that are required in multi-
point applications. Controlled transition times minimize re-
flections that are common in multipoint configurations due to
unterminated stubs.
A single DS91M125 channel is a 1:4 repeater that accepts
M-LVDS/LVDS/CML/LVPECL signals and converts them to
M-LVDS signal levels. Each output has an associated inde-
pendent driver enable pin. The DS91M125 input conforms to
the LVDS standard.
The DS91M125 has a flow-through pinout for easy PCB lay-
out. It provides a new alternative for high speed multipoint
interface applications. It is packaged in a space saving
SOIC-16 package.
Features
DC - 125 MHz / 250 Mbps low jitter, low skew, low power
operation
Independent Driver Enable pins
Outputs Conform to TIA/EIA-899 M-LVDS Standard
Controlled transition times minimize reflections
Inputs Conform to TIA/EIA-644-A LVDS Standard
8 kV ESD on M-LVDS output pins protects adjoining
components
Flow-through pinout simplifies PCB layout
Industrial operating temperature range (−40°C to +85°C)
Available in a space saving SOIC-16 package
Applications
Multidrop / Multipoint clock and data distribution
High-Speed, Low Power, Short-Reach alternative to
TIA/EIA-485/422
Clock distribution in AdvancedTCA (ATCA) and MicroTCA
(μTCA, uTCA) backplanes
Typical Application
30054202
© 2009 National Semiconductor Corporation 300542 www.national.com
DS91M125 125 MHz 1:4 M-LVDS Repeater with LVDS Input
Ordering Information
Order Number Function Package Type
DS91M125TMA 1:4 Repeater SOIC-16
Connection Diagram
30054201
Logic Diagram
30054203
Pin Descriptions
Number Name I/O, Type Description
1, 2, 3, 8 DE I, LVCMOS Driver enable pins: When DE is low, the driver is disabled. When
DE is high, the driver is enabled. There is a 300 k pulldown
resistor on each pin.
6 DI+ I, LVDS Non-inverting receiver input pin.
7 DI- I, LVDS Inverting receiver input pin.
5 GND Power Ground pin.
10, 11, 14, 15 A O, M-LVDS Non-inverting driver output pin.
9, 12, 13, 16 B O, M-LVDS Inverting driver output pin.
4 VDD Power Power supply pin, +3.3V ± 0.3V
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DS91M125
Absolute Maximum Ratings (Note 4)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage −0.3V to +4V
LVCMOS Input Voltages −0.3V to (VDD + 0.3V)
M-LVDS Output Voltages −1.9V to +5.5V
LVDS Input Voltages −0.3V to (VDD + 0.3V)
Maximum Package Power Dissipation at +25°C
SOIC Package 2.21W
Derate SOIC Package 19.2 mW/°C above +25°C
Thermal Resistance (4-Layer, 2 oz. Cu, JEDEC)
 θJA 52°C/W
 θJC 19°C/W
Maximum Junction Temperature 140°C
Storage Temperature Range −65°C to +150°C
Lead Temperature
(Soldering, 4 seconds) 260°C
ESD Susceptibility
HBM (Note 1) 8 kV
MM (Note 2) 250V
CDM (Note 3) 1250V
Note 1: Human Body Model, applicable std. JESD22-A114C
Note 2: Machine Model, applicable std. JESD22-A115-A
Note 3: Field Induced Charge Device Model, applicable std.
JESD22-C101-C
Recommended Operating
Conditions
Min Typ Max Units
Supply Voltage, VDD 3.0 3.3 3.6 V
Voltage at M-LVDS Outputs −1.4 +3.8 V
Voltage at LVDS Inputs 0 VDD V
LVCMOS Input Voltage High VIH 2.0 VDD V
LVCMOS Input Voltage Low VIL 0 0.8 V
Operating Free Air
Temperature TA−40 +25 +85 °C
Electrical Characteristics
Over recommended operating supply and temperature ranges unless otherwise specified. (Note 5, Note 6, Note 7, Note 10)
Symbol Parameter Conditions Min Typ Max Units
LVCMOS DC Specifications
VIH High-Level Input Voltage 2.0 VDD V
VIL Low-Level Input Voltage GND 0.8 V
IIH High-Level Input Current VIH = 3.6V -15 ±1 15 μA
IIL Low-Level Input Current VIL = 0V -15 ±1 15 μA
VCL Input Clamp Voltage IIN = -18 mA -1.5 V
M-LVDS Driver DC Specifications
|VAB| Differential output voltage magnitude RL = 50Ω, CL = 5pF 480 650 mV
ΔVAB Change in differential output voltage magnitude
between logic states
Figures 1, 3 −50 0 +50 mV
VOS(SS) Steady-state common-mode output voltage RL = 50Ω, CL = 5pF 0.3 1.6 2.1 V
VOS(SS)|Change in steady-state common-mode output
voltage between logic states
Figures 1, 2 0 +50 mV
VA(OC) Maximum steady-state open-circuit output voltage Figure 4 0 2.4 V
VB(OC) Maximum steady-state open-circuit output voltage 0 2.4 V
VP(H) Voltage overshoot, low-to-high level output RL = 50Ω, CL = 5pF, CD = 0.5pF
Figures 6, 7 (Note 8) 1.2VSS V
VP(L) Voltage overshoot, high-to-low level output −0.2VS
S
V
IOS Differential short-circuit output current Figure 5 (Note 9) -43 43 mA
IADriver output current VA = 3.8V, VB = 1.2V 32 µA
VA = 0V or 2.4V, VB = 1.2V −20 +20 µA
VA = −1.4V, VB = 1.2V −32 µA
IBDriver output current VB = 3.8V, VA = 1.2V 32 µA
VB = 0V or 2.4V, VA = 1.2V −20 +20 µA
VB = −1.4V, VA = 1.2V −32 µA
IAB Driver output differential current (IA − IB)VA = VB, −1.4V V 3.8V −4 +4 µA
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DS91M125
Symbol Parameter Conditions Min Typ Max Units
IA(OFF) Driver output power-off current VA = 3.8V, VB = 1.2V,
DE = 0V
0V VDD 1.5V
32 µA
VA = 0V or 2.4V, VB = 1.2V,
DE = 0V
0V VDD 1.5V
−20 +20 µA
VA = −1.4V, VB = 1.2V,
DE = 0V
0V VDD 1.5V
−32 µA
IB(OFF) Driver output power-off current VB = 3.8V, VA = 1.2V,
DE = 0V
0V VDD 1.5V
32 µA
VB = 0V or 2.4V, VA = 1.2V,
DE = 0V
0V VDD 1.5V
−20 +20 µA
VB = −1.4V, VA = 1.2V,
DE = 0V
0V VDD 1.5V
−32 µA
IAB(OFF) Driver output power-off differential current (IA(OFF)
IB(OFF))
VA = VB, −1.4V V 3.8V,
DE = 0V
0V VDD 1.5V
−4 +4 µA
CADriver output capacitance VDD = OPEN 7.8 pF
CBDriver output capacitance 7.8 pF
CAB Driver output differential capacitance 3 pF
CA/B Driver output capacitance balance (CA/CB) 1
LVDS Receiver DC Specifications
VIT+ Positive-going differential input voltage threshold -5 100 mV
VIT− Negative-going differential input voltage threshold −100 -5 mV
VCMR Common mode voltage range VID = 100 mV 0.05 VDD-
0.05
V
IIN Input current VIN = 3.6V, VDD = 3.6V ±1 ±10 µA
VIN = 0V, VDD = 3.6V ±1 ±10 µA
CIN Input capacitance VDD = OPEN 5 pF
POWER SUPPLY CURRENT
ICCD Driver Supply Current RL = 50Ω, DE = VDD 67 78 mA
ICCZ TRI-STATE Supply Current DE = GND 21 26 mA
Note 4: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability
and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in
the Recommended Operating Conditions is not implied. The Recommended Operating Conditions indicate conditions at which the device is functional and the
device should not be operated beyond such conditions.
Note 5: The Electrical Characteristics tables list guaranteed specifications under the listed Recommended Operating Conditions except as otherwise modified
or specified by the Electrical Characteristics Conditions and/or Notes. Typical specifications are estimations only and are not guaranteed.
Note 6: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except VOD and
ΔVOD.
Note 7: Typical values represent most likely parametric norms for VDD = +3.3V and TA = +25°C, and at the Recommended Operation Conditions at the time of
product characterization and are not guaranteed.
Note 8: Specification is guaranteed by characterization and is not tested in production.
Note 9: Output short circuit current (IOS) is specified as magnitude only, minus sign indicates direction only.
Note 10: CL includes fixture capacitance and CD includes probe capacitance.
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DS91M125
Switching Characteristics
Over recommended operating supply and temperature ranges unless otherwise specified. (Note 11, Note 12, Note 18)
Symbol Parameter Conditions Min Typ Max Units
DRIVER AC SPECIFICATION
tPLH Differential Propagation Delay Low to High RL = 50Ω, CL = 5 pF, 3.0 5.5 8.5 ns
tPHL Differential Propagation Delay High to Low CD = 0.5 pF 3.0 5.5 8.5 ns
tSKD1 (tsk(p)) Pulse Skew |tPLHD − tPHLD| (Note 14, Note
19)
Figures 6, 7 65 350 ps
tSKD2 Channel-to-Channel Skew (Note 15, Note
19)
65 400 ps
tSKD3 Part-to-Part Skew (Note 16, Note 19) 2.2 2.5 ns
tSKD4 Part-to-Part Skew (Note 17) 5.5 ns
tTLH (tr) Rise Time (Note 19) 1.1 2.0 3.0 ns
tTHL (tf) Fall Time (Note 19) 1.1 2.0 3.0 ns
tPZH Enable Time (Z to Active High) RL = 50Ω, CL = 5 pF, 6 11 ns
tPZL Enable Time (Z to Active Low ) CD = 0.5 pF 6 11 ns
tPLZ Disable Time (Active Low to Z) Figures 8, 9 6 11 ns
tPHZ Disable Time (Active High to Z) 6 11 ns
fMAX Maximum Operating Frequency (Note 19) 125 MHz
Note 11: The Electrical Characteristics tables list guaranteed specifications under the listed Recommended Operating Conditions except as otherwise modified
or specified by the Electrical Characteristics Conditions and/or Notes.
Note 12: Typical values represent most likely parametric norms for VDD = +3.3V and TA = +25°C, and at the Recommended Operation Conditions at the time of
product characterization and are not guaranteed.
Note 13: Specification is guaranteed by characterization and is not tested in production.
Note 14: tSKD1, |tPLHD − tPHLD|, is the magnitude difference in differential propagation delay time between the positive going edge and the negative going edge of
the same channel.
Note 15: tSKD2, Channel-to-Channel Skew, is the difference in propagation delay (tPLHD or tPHLD) among all output channels.
Note 16: tSKD3, Part-to-Part Skew, is defined as the difference between the minimum and maximum specified differential propagation delays. This specification
applies to devices at the same VDD and within 5°C of each other within the operating temperature range.
Note 17: tSKD4, Part-to-Part Skew, is the differential channel-to-channel skew of any event between devices. This specification applies to devices over
recommended operating temperature and voltage ranges, and across process distribution. tSKD4 is defined as |Max − Min| differential propagation delay.
Note 18: CL includes fixture capacitance and CD includes probe capacitance.
Note 19: Specification is guaranteed by characterization and is not tested in production.
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DS91M125
Test Circuits and Waveforms
30054214
FIGURE 1. Differential Driver Test Circuit
30054244
FIGURE 2. Differential Driver Waveforms
30054222
FIGURE 3. Differential Driver Full Load Test Circuit
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DS91M125
30054212
FIGURE 4. Differential Driver DC Open Test Circuit
30054225
FIGURE 5. Differential Driver Short-Circuit Test Circuit
30054216
FIGURE 6. Driver Propagation Delay and Transition Time Test Circuit
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DS91M125
30054218
FIGURE 7. Driver Propagation Delays and Transition Time Waveforms
30054219
FIGURE 8. Driver TRI-STATE Delay Test Circuit
30054221
FIGURE 9. Driver TRI-STATE Delay Waveforms
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DS91M125
Typical Performance Characteristics
30054250
Driver Rise Time as a Function of Temperature
30054251
Driver Fall Time as a Function of Temperature
30054258
Driver Output Signal Amplitude as a Function of Resistive
Load
30054252
Driver Propagation Delay (tPLHD) as a Function of
Temperature
30054253
Driver Propagation Delay (tPHLD) as a Function of
Temperature
30054254
Driver Power Supply Current as a Function of Frequency
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DS91M125
Physical Dimensions inches (millimeters) unless otherwise noted
16-Lead (0.150″ Wide) Molded Small Outline Package, JEDEC
Order Number DS91M125TMA
NS Package Number M16A
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DS91M125
Notes
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DS91M125
Notes
DS91M125 125 MHz 1:4 M-LVDS Repeater with LVDS Input
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