MAXIM MAX9390EHJ+

19-2829; Rev 2; 5/07
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
Also refer to the MAX9392/MAX9393 with flow-through
pinout.
Applications
High-Speed Telecom/Datacom Equipment
High-Level Input Fail-Safe Detection (MAX9390)
Low-Level Input Fail-Safe Detection (MAX9391)
3.0V to 3.6V Supply Voltage Range
LVCMOS/LVTTL Logic Inputs Control Signal
Routing
Ordering Information
TEMP RANGE
PINPACKAGE
PKG
CODE
MAX9390EHJ
-40°C to +85°C
32 TQFP
H32-1
MAX9390EHJ+
-40°C to +85°C
32 TQFP
H32-1
MAX9391EHJ
-40°C to +85°C
32 TQFP
H32-1
MAX9391EHJ+
-40°C to +85°C
32 TQFP
H32-1
PART
+Denotes a lead-free package.
Pin Configurations
VCC
ASEL0
INA0
INA0
GND
TOP VIEW
INA1
Fail-safe circuitry forces the outputs to a differential low
condition for undriven inputs or when the commonmode voltage exceeds the specified range. The
MAX9390 provides high-level input fail-safe detection
for LVDS, HSTL, and other GND-referenced differential
inputs. The MAX9391 provides low-level input fail-safe
detection for LVPECL, CML, and other VCC-referenced
differential inputs.
Ultra-low 82ps(P-P) (max) pseudorandom bit sequence
(PRBS) jitter ensures reliable communications in highspeed links that are highly sensitive to timing error,
especially those incorporating clock-and-data recovery,
or serializers and deserializers. The high-speed switching performance guarantees 1.5GHz operation and less
than 65ps (max) skew between channels.
LVDS inputs and outputs are compatible with the
TIA/EIA-644 LVDS standard. The LVDS outputs drive
100Ω loads. The MAX9390/MAX9391 are offered in a
32-pin TQFP package and operate over the extended
temperature range (-40°C to +85°C).
♦
♦
♦
♦
INA1
Four LVCMOS/LVTTL logic inputs (two per channel) control the internal connections between inputs and outputs.
This flexibility allows for the following configurations: 2 x 2
crosspoint switch, 2:1 mux, 1:2 splitter, or dual repeater.
This makes the MAX9390/MAX9391 ideal for protection
switching in fault-tolerant systems, loopback switching for
diagnostics, fanout buffering for clock/data distribution,
and signal regeneration.
♦ 1.5GHz Operation with 250mV Differential Output
Swing
♦ 2ps(RMS) (max) Random Jitter
♦ AC Specifications Guaranteed for 150mV
Differential Input
♦ Signal Inputs Accept Any Differential Signaling
Standard
♦ LVDS Outputs for Clock or High-Speed Data
ASEL1
The MAX9390/MAX9391 dual 2 x 2 crosspoint switches
perform high-speed, low-power, and low-noise signal
distribution. The MAX9390/MAX9391 multiplex one of two
differential input pairs to either or both low-voltage differential signaling (LVDS) outputs for each channel.
Independent enable inputs turn on or turn off each differential output pair.
Features
32
31
30
29
28
27
26
25
+
ENB1 1
24 VCC
OUTB1 2
23 OUTA0
OUTB1 3
22 OUTA0
21 ENA0
GND 4
MAX9390
MAX9391
ENB0 5
20 GND
Central-Office Backplane Clock Distribution
OUTB0 6
19 OUTA1
DSLAM
OUTB0 7
18 OUTA1
Protection Switching
VCC 8
17 ENA1
14
15
16
BSEL1
INB0
13
INB1
INB0
12
INB1
11
VCC
10
BSEL0
Functional Diagram and Typical Operating Circuit appear at
end of data sheet.
9
GND
Fault-Tolerant Systems
TQFP
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX9390/MAX9391
General Description
MAX9390/MAX9391
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................-0.3V to +4.1V
IN_ _, IN_ _, OUT_ _, OUT_ _, EN_ _,
_SEL_ to GND.........................................-0.3V to (VCC + 0.3V)
IN_ _ to IN_ _ ..........................................................................±3V
Short-Circuit Duration (OUT_ _, OUT_ _) ...................Continuous
Continuous Power Dissipation (TA = +70°C)
32-Pin QFP (derate 13.1mW/°C
above +70°C).............................................................1047mW
Junction-to-Ambient Thermal Resistance in Still Air
32-Pin TQFP............................................................+76.4°C/W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
ESD Protection (Human Body Model)
(IN_ _, IN_ _, OUT_ _, OUT_ _, EN_ _, SEL_ _) ................±2kV
Soldering Temperature (10s) ...........................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(VCC = 3.0V to 3.6V, RL = 100Ω ±1%, EN_ _ = VCC, VCM = 0.05V to (VCC - 0.6V) (MAX9390), VCM = 0.6V to (VCC - 0.05V) (MAX9391) TA =
-40°C to +85°C, unless otherwise noted. Typical values are at VCC = 3.3V, |VID| = 0.2V, VCM = 1.2V, TA = +25°C.) (Notes 1, 2, and 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
LVCMOS/LVTTL INPUTS (EN_ _, _SEL_)
Input High Voltage
VIH
2.0
VCC
Input Low Voltage
VIL
0
0.8
V
Input High Current
IIH
VIN = 2.0V to VCC
0
20
µA
Input Low Current
IIL
VIN = 0 to 0.8V
0
10
µA
Differential Input Voltage
VID
VILD > 0 and VIHD < VCC, Figure 1
0.1
3.0
V
Input Common-Mode Range
VCM
MAX9390
0.05
VCC - 0.6
MAX9391
0.6
VCC - 0.05
Input Current
IIN_ _,
IIN_ _
MAX9390
|VID| < 3.0V
-75
+10
MAX9391
|VID| < 3.0V
-10
+100
VOD
RL = 100Ω, Figure 2
DIFFERENTIAL INPUTS (IN_ _, IN _ _)
V
µA
LVDS OUTPUTS (OUT_ _, OUT_ _)
Differential Output Voltage
Change in Magnitude of VOD
Between Complementary Output
States
Offset Common-Mode Voltage
Change in Magnitude of VOS
Between Complementary Output
States
2
ΔVOD
Figure 2
VOS
Figure 2
ΔVOS
Figure 2
250
1.125
350
450
mV
1.0
50
mV
1.25
1.375
V
1.0
50
mV
_______________________________________________________________________________________
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
(VCC = 3.0V to 3.6V, RL = 100Ω ±1%, EN_ _ = VCC, VCM = 0.05V to (VCC - 0.6V) (MAX9390), VCM = 0.6V to (VCC - 0.05V) (MAX9391) TA =
-40°C to +85°C, unless otherwise noted. Typical values are at VCC = 3.3V, |VID| = 0.2V, VCM = 1.2V, TA = +25°C.) (Notes 1, 2, and 3)
PARAMETER
SYMBOL
CONDITIONS
TYP
MAX
VOUT_ _ or V OUT_ _ = 0
MIN
30
40
VOUT_ _ = V OUT_ _ = 0
18
24
Output Short-Circuit Current
(Either Output Shorted to GND)
|IOS|
VID = ±100mV
(Note 4)
Output Short-Circuit Current
(Outputs Shorted Together)
|IOSB|
VID = ±100mV, VOUT_ _ = V OUT_ _
(Note 4)
5.0
12
RL = 100Ω, EN_ _ = VCC
68
98
RL = 100Ω, EN_ _ = VCC, switching at
670MHz (1.34Gbps)
68
98
UNITS
mA
mA
SUPPLY CURRENT
Supply Current
ICC
mA
AC ELECTRICAL CHARACTERISTICS
(VCC = 3.0V to 3.6V, fIN < 1.34GHz, tR_IN = tF_IN = 125ps, RL = 100Ω ±1%, |VID| > 150mV, VCM = 0.075V to (VCC - 0.6V) (MAX9390
only), VCM = 0.6V to (VCC - 0.075V) (MAX9391 only), EN_ _ = VCC, TA = -40°C to +85°C, unless otherwise noted. Typical values are
at VCC = 3.3V, |VID| = 0.2V, VCM = 1.2V, fIN = 1.34GHz, TA = +25°C.) (Note 5)
PARAMETER
MAX
UNITS
tSWITCH
Figure 3
1.1
ns
Disable, Time to Differential
Output Low
tPHD
Figure 4
1.7
ns
Enable, Time to Differential
Output High
tPDH
Figure 4
1.7
ns
Switching Frequency
fMAX
VOD > 250mV
1.50
2.20
Low-to-High Propagation Delay
tPLH
Figures 1, 5
294
409
565
ps
High-to-Low Propagation Delay
tPHL
Figures 1, 5
286
402
530
ps
_SEL_ to Switched Output
SYMBOL
CONDITIONS
MIN
TYP
GHz
Pulse Skew |tPLH - tPHL|
tSKEW
Figures 1, 5 (Note 6)
7
97
ps
Output-to-Output Skew
tCCS
Figures 5, 6 (Note 7)
10
65
ps
Output Low-to-High Transition
Time (20% to 80%)
tR
Figures 1, 5; fIN = 100MHz
112
153
185
ps
Output High-to-Low Transition
Time (80% to 20%)
tF
Figures 1, 5; fIN = 100MHz
112
153
185
ps
Added Random Jitter
tRJ
fIN_ _ = 1.34GHz, clock pattern (Note 8)
2
ps(RMS)
Added Deterministic Jitter
tDJ
1.34Gbps, 223 - 1 PRBS (Note 8)
55
82
ps(P-P)
Measurements obtained with the device in thermal equilibrium. All voltages referenced to GND except VID, VOD, and ΔVOD.
Current into the device defined as positive. Current out of the device defined as negative.
DC parameters tested at TA = +25°C and guaranteed by design and characterization for TA = -40°C to +85°C.
Current through either output.
Guaranteed by design and characterization. Limits set at ±6 sigma.
tSKEW is the magnitude difference of differential propagation delays for the same output over same conditions. tSKEW =
|tPHL - tPLH|.
Note 7: Measured between outputs of the same device at the signal crossing points for a same-edge transition, under the same
conditions.
Note 8: Device jitter added to the differential input signal.
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
_______________________________________________________________________________________
3
MAX9390/MAX9391
DC ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VCC = 3.3V, |VID| = 0.2V, VCM = 1.2V, fIN = 1.34GHz, TA = +25°C.)
VCC = 3.6V
66
VCC = 3.3V
250
200
150
10
35
60
140
-40
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
85
-15
10
35
60
FREQUENCY (GHz)
TEMPERATURE (°C)
PROPAGATION DELAY
vs. TEMPERATURE
MAX9390
DIFFERENTIAL INPUT CURRENT
vs. TEMPERATURE
MAX9391
DIFFERENTIAL INPUT CURRENT
vs. TEMPERATURE
400
390
380
370
360
-10
-15
-20
-25
-30
-35
-40
VIN = 0.1V
70
60
-15
10
35
60
85
30
20
VIN = 0.3V
-10
-40
-15
10
35
85
60
-40
-15
35
MAX9391
DIFFERENTIAL INPUT CURRENT vs. VILD
80
MAX9390 toc07
VCC = 3V
VCC = 3.6V
70
IN_ _ OR
IN_ _ = VCC
VCC = 3.6V
60
INPUT CURRENT (μA)
IN_ _ OR
IN_ _ = GND
10
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX9390 INPUT CURRENT vs. VIHD
-10
-15
-20
-25
-30
-35
40
0
TEMPERATURE (°C)
10
5
0
-5
VIN = 3.2V
50
10
-45
-50
350
85
MAX9390 toc06
VIN = 3V
MAX9390 toc08
410
80
INPUT CURRENT (μA)
INPUT CURRENT (μA)
420
10
5
0
-5
MAx9390 toc05
MAX9390 toc04
430
INPUT CURRENT (μA)
tR
150
TEMPERATURE (°C)
440
-40
tF
120
0
-15
160
130
50
450
50
40
30
VCC = 3V
20
10
-40
-45
-50
4
fIN = 100MHz
170
100
54
-40
MAX9390 toc03
MAX9390 toc02
300
VCC = 3V
58
180
RISE/FALL TIME (ps)
74
62
350
OUTPUT AMPLITUDE (mV)
78
SUPPLY CURRENT (mA)
400
MAX9390 toc01
82
70
OUTPUT RISE AND FALL TIMES
vs. TEMPERATURE
OUTPUT AMPLITUDE
vs. FREQUENCY
SUPPLY CURRENT
vs. TEMPERATURE
PROPAGATION DELAY (ps)
MAX9390/MAX9391
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
0
-10
0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3 3.6
0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3 3.6
VIHD (V)
VILD (V)
_______________________________________________________________________________________
60
85
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
PIN
NAME
FUNCTION
1
ENB1
2
OUTB1
B1 LVDS Noninverting Output. Connect a 100Ω termination resistor between OUTB1 and OUTB1 at the
receiver inputs to ensure proper operation.
3
OUTB1
B1 LVDS Inverting Output. Connect a 100Ω termination resistor between OUTB1 and OUTB1 at the
receiver inputs to ensure proper operation.
4, 9,
20, 25
GND
Ground
5
ENB0
B0 Output Enable. Drive ENB0 high to enable the B0 LVDS outputs. An internal 435kΩ resistor pulls ENB0
low when unconnected.
6
OUTB0
B0 LVDS Noninverting Output. Connect a 100Ω termination resistor between OUTB0 and OUTB0 at the
receiver inputs to ensure proper operation.
7
OUTB0
B0 LVDS Inverting Output. Connect a 100Ω termination resistor between OUTB0 and OUTB0 at the
receiver inputs to ensure proper operation.
8, 13,
24, 29
VCC
Power-Supply Input. Bypass each VCC to GND with 0. 1µF and 0.01µF ceramic capacitors. Install both
bypass capacitors as close to the device as possible, with the 0.01µF capacitor closest to the device.
10
INB0
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Inverting Input. An internal 128kΩ resistor to VCC pulls
the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low when
unconnected (MAX9391).
11
INB0
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Noninverting Input. An internal 128kΩ resistor to VCC
pulls the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low
when unconnected (MAX9391).
12
BSEL0
Input Select for B0 Output. Selects the differential input to reproduce at the B0 differential outputs. Connect
BSEL0 to GND or leave open to select the INB0 (INB0) set of inputs. Connect BSEL0 to VCC to select the
INB1 (INB1) set of inputs. An internal 435kΩ resistor pulls BSEL0 low when unconnected.
14
INB1
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Inverting Input. An internal 128kΩ resistor to VCC pulls
the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low when
unconnected (MAX9391).
15
INB1
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Noninverting Input. An internal 128kΩ resistor to VCC
pulls the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low
when unconnected (MAX9391).
16
BSEL1
B1 Output Enable. Drive ENB1 high to enable the B1 LVDS outputs. An internal 435kΩ resistor pulls ENB1
low when unconnected.
Input Select for B1 Output. Selects the differential input to reproduce at the B1 differential outputs. Connect
BSEL1 to GND or leave open to select the INB0 (INB0) set of inputs. Connect BSEL1 to VCC to select the
INB1 (INB1) set of inputs. An internal 435kΩ resistor pulls BSEL1 low when unconnected.
_______________________________________________________________________________________
5
MAX9390/MAX9391
Pin Description
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
MAX9390/MAX9391
Pin Description (continued)
6
PIN
NAME
FUNCTION
17
ENA1
18
OUTA1
A1 LVDS Inverting Output. Connect a 100Ω termination resistor between OUTA1 and OUTA1 at the
receiver inputs to ensure proper operation.
19
OUTA1
A1 LVDS Noninverting Output. Connect a 100Ω termination resistor between OUTA1 and OUTA1 at the
receiver inputs to ensure proper operation.
21
ENA0
22
OUTA0
A0 LVDS Inverting Output. Connect a 100Ω termination resistor between OUTA0 and OUTA0 at the
receiver inputs to ensure proper operation.
23
OUTA0
A0 LVDS Noninverting Output. Connect a 100Ω termination resistor between OUTA0 and OUTA0 at the
receiver inputs to ensure proper operation.
26
INA0
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Noninverting Input. An internal 128kΩ resistor to VCC
pulls the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low
when unconnected (MAX9391).
27
INA0
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Inverting Input. An internal 128kΩ resistor to VCC pulls
the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low when
unconnected (MAX9391).
28
ASEL0
Input Select for A0 Output. Selects the differential input to reproduce at the A0 differential outputs. Connect
ASEL0 to GND or leave open to select the INA0 (INA0) set of inputs. Connect ASEL0 to VCC to select the
INA1 (INA1) set of inputs. An internal 435kΩ resistor pulls ASEL0 low when unconnected.
30
INA1
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Noninverting Input. An internal 128kΩ resistor to VCC
pulls the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low
when unconnected (MAX9391).
31
INA1
LVDS/HSTL (MAX9390) or LVPECL/CML (MAX9391) Inverting Input. An internal 128kΩ resistor to VCC pulls
the input high when unconnected (MAX9390). An internal 68kΩ resistor to GND pulls the input low when
unconnected (MAX9391).
32
ASEL1
Input Select for A1 Output. Selects the differential input to reproduce at the A1 differential outputs. Connect
ASEL1 to GND or leave open to select the INA0 (INA0) set of inputs. Connect ASEL1 to VCC to select the
INA1 (INA1) set of inputs. An internal 435kΩ resistor pulls ASEL1 low when unconnected.
A1 Output Enable. Drive ENA1 high to enable the A1 LVDS outputs. An internal 435kΩ resistor pulls ENA1
low when unconnected.
A0 Output Enable. Drive ENA0 high to enable the A0 LVDS outputs. An internal 435kΩ resistor pulls ENA0
low when unconnected.
_______________________________________________________________________________________
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
MAX9390/MAX9391
VIN_ _
VIHD
VID = 0
VID = 0
tPLH
tPHL
VIN_ _
VILD
OUT_ _
1/4 MAX9390/MAX9391
VOUT_ _
VOD
RL/2
VOD = 0
VOD = 0
IN_ _
VOS
VOUT_ _
IN_ _
RL/2
80%
VOD = 0
50%
80%
EN_ _ = HIGH
VID = VIN_ _ - VIN_ _
VOD = 0
50%
20%
20%
tR
OUT_ _
ΔVOD = ⎪VOD - VOD*⎪
ΔVOS = ⎪VOS - VOS*⎪
VOD AND VOS ARE MEASURED WITH VID = +100mV
VOD* AND VOS* ARE MEASURED WITH VID = -100mV
tF
VID = VIN_ _ - VIN_ _
VOD = VOUT_ _ - VOUT_ _
tPLH AND tPHL MEASURED FOR ANY COMBINATION OF _SEL0 AND _SEL1.
Figure 1. Output Transition Time and Propagation Delay Timing
Diagram
Figure 2. Test Circuit for VOD and VOS
VIHD
IN_0
VID = 0
VILD
IN_0
VIHD
IN_1
VID = 0
VILD
IN_1
VIH
1.5V
1.5V
VIL
_SEL_
OUT_ _
IN_0
VOD = 0
IN_1 VOD = 0
IN_0
OUT_ _
tSWITCH
tSWITCH
EN_0 = EN_1 = HIGH
VID = VIN_ _ - VIN_ _
Figure 3. Input to Rising/Falling Edge Select and Mux Switch Timing Diagram
_______________________________________________________________________________________
7
MAX9390/MAX9391
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
OUT_ _
1/4 MAX9390/MAX9391
1.5V
VEN_ _
CL
3V
1.5V
0
RL/2
IN_ _
tPHD
IN_ _
1.25V
RL/2
PULSE
GENERATOR
VOUT_ _ WHEN VID = +100mV
VOUT_ _ WHEN VID = -100mV
tPDH
50%
50%
50%
50%
OUT_ _
VOUT_ _ WHEN VID = -100mV
VOUT_ _ WHEN VID = +100mV
CL
50Ω
tPHD
RL = 100Ω ±1%
CL = 1.0pF
tPDH
VID = VIN_ _ - VIN_ _
Figure 4. Output Active-to-Disable and Disable-to-Active Test Circuit and Timing Diagram
_SEL0
IN_0
CL
OUT_0
0
IN_0
RL
1
PULSE
GENERATOR
50Ω
OUT_0
CL
MAX9390
MAX9391
50Ω
CL
OUT_1
0
RL
IN_1
1
IN_1
CL
_SEL1
EN_0 = EN_1 = HIGH
1 CHANNEL SHOWN
RL = 100Ω ±1%
CL = 1.0pF
Figure 5. Output Transition Time, Propagation Delay, and Output Channel-to-Channel Skew Test Circuit
8
_______________________________________________________________________________________
OUT_1
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
MAX9390/MAX9391
VOUT_0
VOD = 0
VOD = 0
tCCS
tCCS
IN_0
OUT_0
IN_1
OUT_1
VOUT_0
VOUT_1
VOD = 0
2 x 2 CROSSPOINT
VOD = 0
VOUT_1
VOD = VOUT_ _ - VOUT_ _
IN_0
tCCS MEASURED WITH _SEL0 = _SEL1 = HIGH OR LOW
(1:2 SPLITTER CONFIGURATION).
OUT_0 OR OUT_1
IN_1
Figure 6. Output Channel-to-Channel Skew
2:1 MUX
Detailed Description
The LVDS interface standard provides a signaling
method for point-to-point communication over a controlled-impedance medium as defined by the ANSI
TIA/EIA-644 standard. LVDS utilizes a lower voltage
swing than other communication standards, achieving
higher data rates with reduced power consumption,
while reducing EMI emissions and system susceptibility
to noise.
The MAX9390/MAX9391 1.5GHz dual 2 x 2 crosspoint
switches optimize high-speed, low-power, point-topoint interfaces. The MAX9390 accepts LVDS and
HSTL signals, while the MAX9391 accepts LVPECL and
CML signals. Both devices route the input signals to
either or both LVDS outputs.
When configured as a 1:2 splitter, the outputs repeat
the selected inputs. This configuration creates copies
of signals for protection switching. When configured as
a repeater, the device operates as a two-channel
buffer. Repeating restores signal amplitude, allowing
isolation of media segments or longer media drive.
When configured as a 2:1 mux, select primary or backup signals to provide a protection-switched, fault-tolerant application.
Input Fail-Safe
The differential inputs of the MAX9390/MAX9391 possess internal fail-safe protection. Fail-safe circuitry
forces the outputs to a differential low condition for
undriven inputs or when the common-mode voltage
exceeds the specified range. The MAX9390 provides
high-level input fail-safe detection for LVDS, HSTL, and
other GND-referenced differential inputs. The MAX9391
provides low-level input fail-safe detection for LVPECL,
CML, and other VCC-referenced differential inputs.
OUT_0
IN_0 OR IN_1
OUT_1
1:2 SPLITTER
IN_0
OUT_0
IN_1
OUT_1
DUAL REPEATER
Figure 7. Programmable Configurations
Select Function
The _SEL_ logic inputs control the input and output signal connections. Two logic inputs control the signal routing for each channel. _SEL0 and _SEL1 allow the
devices to be configured as a differential crosspoint
switch, 2:1 mux, dual repeater, or 1:2 splitter (Figure 7).
See Table 1 for mode-selection settings (insert A or B for
the _). Channels A and B possess separate select
inputs, allowing different configurations for each channel.
Enable Function
The EN_ _ logic inputs enable and disable each set of
differential outputs. Connect EN_ 0 to VCC to enable
the OUT_0/OUT_0 differential output pair. Connect
EN_0 to GND to disable the OUT_0/OUT_0 differential
output pair. The differential output pairs assert to a differential low condition when disabled.
_______________________________________________________________________________________
9
MAX9390/MAX9391
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
Table 1. Input/Output Function Table
_SEL0
_SEL1
OUT_0 / OUT_0
OUT_1 / OUT_1
MODE
0
0
IN_0 / IN_0
IN_0 / IN_0
1:2 splitter
0
1
IN_0 / IN_0
IN_1 / IN_1
Repeater
1
0
IN_1 / IN_1
IN_0 / IN_0
Switch
1
1
IN_1 / IN_1
IN_1 / IN_1
1:2 splitter
Applications Information
Differential Inputs
The MAX9390/MAX9391 inputs accept any differential
signaling standard within the specified common-mode
voltage range. The fail-safe feature detects commonmode input signal levels and generates a differential
output low condition for undriven inputs or when the
common-mode voltage exceeds the specified range.
Leave unused inputs unconnected or connect to VCC
for the MAX9390 or to GND for the MAX9391.
Differential Outputs
The output common-mode voltage is not properly
established if the LVDS output is higher than 0.6V when
the supply voltage is ramping up at power-on. This
condition can occur when an LVDS output drives an
LVDS input on the same chip. To avoid this situation for
the MAX9390/MAX9391, connect a 10kΩ resistor from
the noninverting output (OUT_) to ground, and connect
a 10kΩ resistor from the inverting output (OUT_) to
ground. These pulldown resistors keep the output
below 0.6V when the supply is ramping up (Figure 8).
Expanding the Number of LVDS Output
Ports
Cascade devices to make larger switches. Consider
the total propagation delay and total jitter when determining the maximum allowable switch size.
Power-Supply Bypassing
Bypass each VCC to GND with high-frequency surfacemount ceramic 0.1µF and 0.01µF capacitors in parallel
as close to the device as possible. Install the 0.01µF
capacitor closest to the device.
Differential Traces
Input and output trace characteristics affect the performance of the MAX9390/MAX9391. Connect each input
and output to a 50Ω characteristic impedance trace.
Maintain the distance between differential traces and
eliminate sharp corners to avoid discontinuities in differential impedance and maximize common-mode
noise immunity. Minimize the number of vias on the differential input and output traces to prevent impedance
10
discontinuities. Reduce reflections by maintaining the
50Ω characteristic impedance through connectors and
across cables. Minimize skew by matching the electrical length of the traces.
Output Termination
Terminate LVDS outputs with a 100Ω resistor between
the differential outputs at the receiver inputs. LVDS outputs require 100Ω termination for proper operation.
Ensure that the output currents do not exceed the current limits specified in the Absolute Maximum Ratings.
Observe the total thermal limits of the MAX9390/
MAX9391 under all operating conditions.
Cables and Connectors
Use matched differential impedance for transmission
media. Use cables and connectors with matched differential impedance to minimize impedance discontinuities. Avoid the use of unbalanced cables. Balanced
cables such as twisted pair offer superior signal quality
and tend to generate less EMI due to canceling effects.
Board Layout
Use a four-layer printed circuit (PC) board providing
separate signal, power, and ground planes for highspeed signaling applications. Bypass VCC to GND as
close to the device as possible. Install termination
resistors as close to receiver inputs as possible. Match
the electrical length of the differential traces to minimize
signal skew.
100Ω DIFFERENTIAL
TRANSMISSION LINE
MAX9390
MAX9391
OUT_
100Ω
OUT_
10kΩ
10kΩ
TERMINATION
RESISTOR
GND
Figure 8. Pulldown Resistor Configuration for LVDS Outputs
______________________________________________________________________________________
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
3.0V TO
3.6V
0.1μF
0.01μF
VCC
Z0 = 50Ω
OUTA0
INA0
Z0 = 50Ω
100Ω
100Ω
Z0 = 50Ω
MAX9390
MAX9391
INA0
OUTA0
Z0 = 50Ω
OUTA1
Z0 = 50Ω
INA1
INA1
INB0
LVDS
RECEIVER
MAX9173
INB0
OUTA1
Z0 = 50Ω
OUTB0
Z0 = 50Ω
OUTB0
Z0 = 50Ω
OUTB1
Z0 = 50Ω
OUTB1
Z0 = 50Ω
INB1
INB1
ENA0
ENA1
ENB0
ENB1
LVCMOS/LVTTL
LOGIC INPUTS
ASEL0
ASEL1
BSEL0
BSEL1
GND
GND
GND
GND
______________________________________________________________________________________
11
MAX9390/MAX9391
Typical Operating Circuit
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
MAX9390/MAX9391
Functional Diagram
Chip Information
TRANSISTOR COUNT: 1565
PROCESS: BIPOLAR
INA0
INA0
MAX9390
MAX9391
0
OUTA0
OUTA0
ENA0
1
ASEL0
INA1
INA1
1
OUTA1
OUTA1
ENA1
0
ASEL1
INB0
OUTB0
0
INB0
OUTB0
ENB0
1
BSEL0
INB1
OUTB1
OUTB1
ENB1
1
INB1
0
BSEL1
12
______________________________________________________________________________________
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
32L TQFP, 5x5x01.0.EPS
PACKAGE OUTLINE, 32L TQFP, 5x5x1.0mm
21-0110
B
1
2
______________________________________________________________________________________
13
MAX9390/MAX9391
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
MAX9390/MAX9391
Anything-to-LVDS Dual 2 x 2
Crosspoint Switches
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, 32L TQFP, 5x5x1.0mm
21-0110
B
2
2
Revision History
Pages changed at Rev 2: 1–4, 6, 8, 10–14
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
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is a registered trademark of Maxim Integrated Products, Inc.