MAXIM MAX4986CTO+

19-5127; Rev 1; 7/12
TION KIT
EVALUA BLE
A
IL
A
V
A
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
The MAX4986 active 2:1/1:2 multiplexer/demultiplexer
equalizes and redrives SAS/SATA or SATA-only signals
up to 6.0Gbps and operates from a single +3.3V supply.
The MAX4986 features independent input equalization
and output preemphasis. The MAX4986 enhances signal integrity at the receiver by equalizing the signal at
the input and establishing preemphasis at the output
of the device. SAS/SATA and SATA-only out-of-band
(OOB) signaling is supported using high-speed amplitude detection on the inputs and squelch on the corresponding outputs. Inputs and outputs are internally 50I
terminated and must be AC-coupled to the SAS/SATA
controller IC and SAS/SATA device.
The MAX4986 is available in a small (3.5mm x 9.0mm),
42-pin TQFN package optimal for simplified layout and
space-saving requirements. The MAX4986C is specified
over the 0NC to +70NC commercial operating temperature range. The MAX4986E is specified over the -40NC to
+85NC extended temperature range.
Applications
Features
SSingle +3.3V Supply Operation
SLow-Power, 1mA (typ) Standby
Active-High Enable (EN) for Use with Power Good
Active-Low Enable (EN) for Cable-Detect Function
SSupports SAS I/II/III P 6.0Gbps
SIndependent Programmable Input Equalization
Two Levels: 0dB, 4dB
SIndependent Programmable Output Preemphasis
Two Levels: 0dB, 3dB
SIndependent Programmable Output Level
Selection
SSupports SAS/SATA OOB-Level Signaling
Programmable SAS/SATA Threshold
SCable-Detect Feature for Low Power Consumption
SOn-Chip 50I Input/Output Terminations
SInline Signal Traces for Simplified Layout
SSpace-Saving, 3.5mm x 9.0mm TQFN Package
with Exposed Pad
Ordering Information
PC Servers
Workstations
Desktops
Docking Stations
PART
MAX4986CTO+
TEMP RANGE
0NC to +70NC
PIN-PACKAGE
42 TQFN-EP*
MAX4986ETO+
-40NC to +85NC
42 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX4986
General Description
MAX4986
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
ABSOLUTE MAXIMUM RATINGS
(Voltages Referenced to GND.)
VCC ...................................................................... -0.3V to +4.0V
All Other Pins (Note 1) ............................ -0.3V to (VCC + 0.3V)
Continuous Current IN_P, IN_M, OUT_P, OUT_M ......... Q30mA
Peak Current IN_P, IN_M, OUT_P, OUT_M for 1Fs ..... Q100mA
Continuous Power Dissipation (TA = +70NC)
42-Pin TQFN (derate 34.5mW/NC above +70NC) ..... 2758mW
Operating Temperature Range ......................... -40NC to +85NC
Junction Temperature Range ......................... -40NC to +150NC
Storage Temperature Range .......................... -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Note 1: All I/O pins are clamped by internal diodes.
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.
ELECTRICAL CHARACTERISTICS
(VCC = +3.0V to +3.6V, CCL = 10nF coupling capacitor on each input and output, RL = 50I on each input and output, TA = 0NC to +70NC
(MAX4986C), TA = -40NC to +85NC (MAX4986E), unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
3.6
V
DC PERFORMANCE
Power-Supply Range
Standby Current
Supply Current
VCC
ISTBY
ICC
3.0
2.5
4
1.0
2
OUTPE = PEA = PEB = 0,
INEQ = EQA = EQB = 0
145
170
OUTPE = PEA = PEB = 1,
INEQ = EQA = EQB = 1
185
EN = 0 or EN = 1, VCC = 3.6V
EN = 0 or EN = 1, VCC = 3.3V
mA
mA
230
Input Termination, Single-Ended
RRX-SE
DC
42.5
57.5
I
Output Termination, SingleEnded
RTX-SE
DC
42.5
57.5
I
AC PERFORMANCE
Input Return Loss, Differential
(Note 3)
SDD11
Input Return Loss,
Common Mode (Note 3)
SCC11
Output Return Loss, Differential
(Note 3)
SDD22
Output Return Loss,
Common Mode (Note 3)
SCC22
Differential Input Voltage
Input Equalization
Differential Output Voltage
2 VIN-DIFF
EQ
VOUT-DIFF
0.1GHz < f P 0.3GHz
-10
0.3GHz < f P 3.0GHz
-7.9
3.0GHz < f P 6.0GHz
0
0.1GHz < f P 0.3GHz
-6
0.3GHz < f P 3.0GHz
-5
3.0GHz < f P 6.0GHz
0
0.1GHz < f P 0.3GHz
-10
0.3GHz < f P 3.0GHz
-7.9
3.0GHz < f P 6.0GHz
0
0.1GHz < f P 0.3GHz
-6
0.3GHz < f P 3.0GHz
-5
3.0GHz < f P 6.0GHz
0
SAS 1.5Gbps, 3Gbps, MODE_ = 0
275
1600
SAS 6Gbps, MODE_ = 0
300
1600
SATA 1.5Gbps, 3Gbps, 6Gbps, MODE_ = 1
225
1600
f = 1.5GHz, INEQ = 1
f = 0.75GHz, 1.5GHz,
PE_ = 0
4
dB
dB
dB
dB
mVP-P
dB
OAMP_ = 0
700
1200
OAMP_ = 1
425
700
mVP-P
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
(VCC = +3.0V to +3.6V, CCL = 10nF coupling capacitor on each input and output, RL = 50I on each input and output, TA = 0NC to +70NC
(MAX4986C), TA = -40NC to +85NC (MAX4986E), unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 2)
PARAMETER
SYMBOL
Output Preemphasis
PE
Propagation Delay
tPD
Output Transition Time
tTX-RF
Differential Output Skew Same
Pair
tSK
Deterministic Jitter
tDJ
Random Jitter
tTX-RJ-DD
CONDITIONS
MIN
f = 1.5GHz, PE_ = 1, Figure 1
f < 3.0GHz, PE_ = 0 (Notes 3, 4)
40
TYP
UNITS
dB
300
ps
60
ps
10
ps
K28.5Q pattern, PE_ = 0, EQ_ = 0 (Note 3)
D10.2 pattern, PE_ = 0, EQ_ = 0
MAX
3
1
20
psP-P
1.5
psRMS
MODE_ = 0
120
220
MODE_ = 1
50
150
OOB Squelch Threshold
VSQ-DIFF
f = 0.75GHz (Note 3)
mVP-P
OOB Squelch Time
tOOB,SQ
f = 0.75GHz (Note 3)
5
10
ns
OOB Exit Time
tOOB,EX
f = 0.75GHz (Note 3)
5
10
ns
OOB Differential-Offset Delta
Difference between OOB and active-mode
DVOOB,DIFF
output offset
-80
80
mV
OOB Common-Mode Delta
DVOOB,CM
Difference between OOB and active-mode
output VCM
-50
50
mV
OOB Output Disable
VOOB,OUT
OOB-disabled output level
30
mVP-P
CONTROL LOGIC
Input Logic-High
VIH
Input Logic-Low
VIL
Input Logic Hysteresis
Pullup/Pulldown Input Resistor
1.4
V
0.6
V
VHYST
0.1
V
RUP/DOWN
330
kI
Note 2: MAX4986C devices are 100% production tested at TA = +70°C. MAX4986E devices are 100% production tested at TA =
+85°C. Specifications for all temperature limits are guaranteed by design.
Note 3: Guaranteed by design.
Note 4: Rise and fall times are measured using 20% and 80% levels.
VLOW_P-P
PE(dB) = 20log
VHIGH_P-P
VHIGH_P-P
VLOW_P-P
Figure 1. Output Preemphasis
3
MAX4986
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
VIN = 275mVP-P, 1.5Gbps, PE = 0, EQ = 0
VIN = 275mVP-P, 3.0Gbps, PE = 0, EQ = 0
MAX4986 toc01
600
200
200mV/div
200
200mV/div
200
200mV/div
400
0
0
0
-200
-200
-200
-400
-400
-400
-600
-600
-400
-200
0
200
400
MAX4986 toc03
600
400
-600
-600
600
-300
-200
-100
200ps/div
0
100
200
300
-150
VIN = 275mVP-P, 1.5Gbps, PE = 1, EQ = 0
400
400
200
200
200
200mV/div
400
200mV/div
600
0
-200
-200
-400
-400
-400
-600
-600
-600
-800
-200
0
200
400
600
-200
-100
0
100
200
300
-150
200
200
200mV/div
200
200mV/div
400
0
0
-200
-200
-400
-400
-400
0
200ps/div
4 200
400
600
50
100
150
-600
MAX4986 toc09
0
-200
-600
0
600
400
-200
-50
VIN = 1600mVP-P, 6.0Gbps, PE = 0, EQ = 0
MAX4986 toc08
600
400
-400
-100
50ps/div
VIN = 1600mVP-P, 3.0Gbps, PE = 0, EQ = 0
MAX4986 toc07
-600
MAX4986 toc06
100ps/div
VIN = 1600mVP-P, 1.5Gbps, PE = 0, EQ = 0
150
-800
-300
200ps/div
600
100
0
-200
-800
50
800
600
0
0
VIN = 275mVP-P, 6.0Gbps, PE = 1, EQ = 0
MAX4986 toc05
800
600
-400
-50
50ps/div
VIN = 275mVP-P, 3.0Gbps, PE = 1, EQ = 0
MAX4986 toc04
-600
-100
100ps/div
800
200mV/div
VIN = 275mVP-P, 6.0Gbps, PE = 0, EQ = 0
MAX4986 toc02
600
400
200mV/div
MAX4986
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
-600
-300
-200
-100
0
100ps/div
100
200
300
-150
-100
-50
0
50ps/div
50
100
150
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
VIN = 1600mVP-P, 3.0Gbps, PE = 1, EQ = 0
VIN = 1600mVP-P, 1.5Gbps, PE = 1, EQ = 0
MAX4986 toc10
600
600
400
400
200
200
0
MAX4986 toc11
800
200mV/div
200mV/div
800
0
-200
-200
-400
-400
-600
-600
-800
-800
-600
-400
-200
0
200
400
-300
600
-200
-100
0
100
200
300
200ps/div
100ps/div
VIN = 1600mVP-P, 6.0Gbps, PE = 1, EQ = 0
VIN = 500mVP-P WITH 12in FR4 STRIPLINE INPUT,
3.0Gbps, PE = 0, EQ = 0
MAX4986 toc12
800
MAX4986 toc13
600
600
400
200
200
200mV/div
200mV/div
400
0
-200
0
-200
-400
-400
-600
-800
-150
-100
-50
0
50
-600
150
-300
-200
-100
0
100
200
300
50ps/div
100ps/div
VIN = 500mVP-P WITH 12in FR4 STRIPLINE INPUT,
6.0Gbps, PE = 0, EQ = 0
VIN = 500mVP-P WITH 12in FR4 STRIPLINE INPUT,
3.0Gbps, PE = 0, EQ = 1
MAX4986 toc14
600
400
400
200
200
0
MAX4986 toc15
600
200mV/div
200mV/div
100
0
-200
-200
-400
-400
-600
-600
-150
-100
-50
0
50ps/div
50
100
150
-300
-200
-100
0
100
200
300
100ps/div
5
MAX4986
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
VIN = 500mVP-P WITH 12in FR4 STRIPLINE INPUT,
6.0Gbps, PE = 0, EQ = 1
MAX4986 toc17
600
400
400
200
200
200mV/div
200mV/div
VIN = 275mVP-P, 3.0Gbps, PE = 0, EQ = 0
OUTPUT AFTER 12in FR4 STRIPLINE
MAX4986 toc16
600
0
0
-200
-200
-400
-400
-600
-600
-150
-100
-50
0
50
100
150
-300
-200
-100
0
100
200
300
50ps/div
100ps/div
VIN = 275mVP-P, 6.0Gbps, PE = 0, EQ = 0
OUTPUT AFTER 12in FR4 STRIPLINE
VIN = 275mVP-P, 3.0Gbps, PE = 1, EQ = 0
OUTPUT AFTER 12in FR4 STRIPLINE
MAX4986 toc18
500
MAX4986 toc19
600
400
400
300
200
200
100
200mV/div
100mV/div
0
-100
0
-200
-200
-300
-400
-400
-500
-600
-150
-100
-50
0
50
100
150
-300
50ps/div
VIN = 275mVP-P, 6.0Gbps, PE = 1, EQ = 0
OUTPUT AFTER 12in FR4 STRIPLINE
MAX4986 toc20
600
400
200
0
-200
-400
-600
-150
-100
-50
0
50ps/div
6 -200
-100
0
100ps/div
200mV/div
MAX4986
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
50
100
150
100
200
300
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
VCC
GND
INBM
INBP
GND
INAM
INAP
GND
EN
GND
OUTBM
OUTBP
GND
OUTAM
OUTAP
GND
VCC
TOP VIEW
38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22
21 EQA
PEA 39
20 EQB
PEB 40
MAX4986
19 OUTPE
*EP
7
8
9
VCC
OAMPB
GND
INP
INM
GND
SEL1
SEL2
18 OAMP
10 11 12 13 14 15 16 17
MODEA
6
GND
5
OUTM
4
OUTP
3
GND
2
EN
1
OAMPA
+
MODEB
MODE 42
VCC
INEQ 41
TQFN
*CONNECT EXPOSED PAD TO GND.
Pin Description
PIN
NAME
FUNCTION
1, 17, 22, 38
VCC
Power-Supply Input. Bypass VCC to GND with 1FF and 0.01FF capacitors in parallel as close to the
device as possible; recommended for each VCC pin.
2
OAMPA
OUTAP/OUTAM Output Level Selection. Drive OAMPA high for low output amplitude. Drive OAMPA
low or leave unconnected for high output amplitude. See the Electrical Characteristics table.
OAMPA is internally pulled down by a 330kI (typ) resistor.
3
OAMPB
OUTBP/OUTBM Output Level Selection. Drive OAMPB high for low output amplitude. Drive OAMPB
low or leave unconnected for high output amplitude. See the Electrical Characteristics table.
OAMPB is internally pulled down by a 330kI (typ) resistor.
4, 7, 11, 14,
23, 26, 29,
31, 34, 37
GND
5
INP
Channel 1 Noninverting Input
6
INM
Channel 1 Inverting Input
8
SEL1
Channel 1 Active-Output Selection Input. Drive SEL1 low or leave unconnected to activate A
outputs. Drive SEL1 high to activate B outputs. SEL1 is internally pulled down by a 330kI (typ)
resistor.
9
SEL2
Channel 2 Active-Input Selection Input. Drive SEL2 low or leave unconnected to activate A inputs.
Drive SEL2 high to activate B inputs. SEL2 is internally pulled down by a 330kI (typ) resistor.
10
EN
Enable Input. Drive EN low or leave unconnected for reduced power standby mode. Drive EN high
for normal operation. See Table 1. EN is internally pulled down by a 330kI (typ) resistor.
Ground
12
OUTP
Channel 2 Noninverting Output
13
OUTM
Channel 2 Inverting Output
7
MAX4986
Pin Configuration
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
MAX4986
Pin Description (continued)
PIN
8 NAME
FUNCTION
15
MODEA
INAP/INAM OOB-Mode Logic Input. Drive MODEA low or leave unconnected for SAS OOB threshold. Drive MODEA high for SATA OOB threshold. MODEA is internally pulled down by a 330kI
(typ) resistor.
16
MODEB
INBP/INBM OOB-Mode Logic Input. Drive MODEB low or leave unconnected for SAS OOB threshold. Drive MODEB high for SATA OOB threshold. MODEB is internally pulled down by a 330kI
(typ) resistor.
18
OAMP
OUTP/OUTM Output Level Selection. Drive OAMP high for low output amplitude. Drive OAMP low
or leave unconnected for high output amplitude. See the Electrical Characteristics table. OAMP is
internally pulled down by a 330kI (typ) resistor.
19
OUTPE
OUTP/OUTM Output Preemphasis Logic Input. Drive OUTPE low or leave unconnected for no output preemphasis. Drive OUTPE high for 3dB (typ) output preemphasis. OUTPE is internally pulled
down by a 330kI (typ) resistor.
20
EQB
INBP/INBM Input Equalization Logic Input. Drive EQB low or leave unconnected for no input equalization. Drive EQB high for 4dB (typ) input equalization. EQB is internally pulled down by a 330kI
(typ) resistor.
21
EQA
INAP/INAM Input Equalization Logic Input. Drive EQA low or leave unconnected for no input equalization. Drive EQA high for 4dB (typ) input equalization. EQA is internally pulled down by a 330kI
(typ) resistor.
24
INBM
Channel 2 Inverting Input B
25
INBP
Channel 2 Noninverting Input B
27
INAM
Channel 2 Inverting Input A
28
INAP
Channel 2 Noninverting Input A
30
EN
32
OUTBM
Channel 1 Inverting Output B
33
OUTBP
Channel 1 Noninverting Output B
35
OUTAM
Channel 1 Inverting Output A
36
OUTAP
Channel 1 Noninverting Output A
39
PEA
OUTAP/OUTAM Output Preemphasis Logic Input. Drive PEA low or leave unconnected for no output preemphasis. Drive PEA high for 3dB (typ) output preemphasis. PEA is internally pulled down
by a 330kI (typ) resistor.
40
PEB
OUTBP/OUTBM Output Preemphasis Logic Input. Drive PEB low or leave unconnected for no output preemphasis. Drive PEB high for 3dB (typ) output preemphasis. PEB is internally pulled down
by a 330kI (typ) resistor.
41
INEQ
INP/INM Input Equalization Logic Input. Drive INEQ low or leave unconnected for no input equalization. Drive INEQ high for 4dB (typ) input equalization. INEQ is internally pulled down by a 330kI
(typ) resistor.
42
MODE
INP/INM OOB-Mode Logic Input. Drive MODE low or leave unconnected for SAS OOB threshold.
Drive MODE high for SATA OOB threshold. MODE is internally pulled down by a 330kI (typ)
resistor.
—
EP
Active-Low Enable Input. Drive EN high or leave unconnected for reduced power standby mode.
Drive EN low for normal operation. See Table 1. EN is internally pulled up by a 330kI (typ) resistor.
Exposed Pad. Internally connected to GND. Connect EP to a large ground plane to maximize thermal performance.
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
VCC
PEA
PEB
OAMPA
OAMPB
INEQ
MODE
SEL1
VCC
CHANNEL 1
CONTROL
OUTAP
VCC
VCC
INP
OUTBP
INM
EN
EN
OUTAM
VCC
GLOBAL CONTROL
OUTBM
VCC
INAP
OUTP
VCC
INAM
OUTM
SEL2
EQA
EQB
OUTPE
OAMP
MODEA
MODEB
INBP
INBM
CHANNEL 2
CONTROL
MAX4986
GND
9
MAX4986
Functional Diagram
MAX4986
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
Detailed Description
The MAX4986 is an active 2:1/1:2 multiplexer/demultiplexer designed to equalize and redrive SAS/SATA
(Enterprise Class, SATA _X) or SATA-only signals up to
6.0Gbps.
Input/Output Terminations
Inputs and outputs are internally 50I terminated to VCC
and must be AC-coupled using low-ESR, X7R, 10nF
capacitors to the SAS/SATA controller IC and SAS/SATA
device for proper operation.
Enable Inputs (EN, EN)
The MAX4986 features both an active-high enable input
(EN) and an active-low enable input (EN). EN has an
internal pulldown resistor of 330kI (typ), and EN has an
internal pullup resistor of 330kI (typ). When EN is driven
low or left unconnected, or when EN is driven high or
Table 1. Standby Mode
EN
STATUS
0
EN
X
Reduced Power Standby
X
1
Reduced Power Standby
1
0
Active
left unconnected, the MAX4986 enters reduced power
standby mode and the redrivers are disabled. In standby
mode, supply current is reduced to 350FA (typ). Drive
EN high and EN low for normal operation. See Table
1. EN is useful as an automated cable-detect. See the
Typical Application Circuits.
Active Input/Output Select (SEL1, SEL2)
SEL1 selects the active output for channel 1 and SEL2
selects the active input for channel 2. Drive SEL1 or
SEL2 low or leave unconnected to activate A inputs or
outputs. Drive SEL1 or SEL2 high to activate B inputs
or outputs. See Table 2. SEL1 and SEL2 have internal
pulldown resistors of 330kI (typ).
Programmable Output Preemphasis
(OUTPE, PEA, PEB)
The MAX4986 features independent output preemphasis
capable of providing 3dB preemphasis on each channel.
When OUTPE, PEA, or PEB are driven low or left unconnected, the corresponding output has no preemphasis.
When OUTPE, PEA, or PEB are driven high, the corresponding output has 3dB preemphasis. See Table 3.
OUTPE, PEA, and PEB have internal pulldown resistors
of 330kI (typ). Output preemphasis should be used
when driving long traces or cables.
X = Don’t care.
Programmable Input Equalization
(INEQ, EQA, EQB)
Table 2. Active Input/Output Select
SEL1
SEL2
ACTIVE OUTPUT
ACTIVE INPUT
X
0
X
INAP/INAM
X
1
X
INBP/INBM
0
X
OUTAP/OUTAM
X
1
X
OUTBP/OUTBM
X
X = Don’t care.
The MAX4986 features independent input equalization
capable of providing 4dB of high-frequency equalization
on each channel. When INEQ, EQA, or EQB are driven
low or left unconnected, the corresponding input has no
equalization. When INEQ, EQA, or EQB are driven high,
the corresponding input has 4dB equalization. See Table 4.
INEQ, EQA, and EQB have internal pulldown resistors of
330kI (typ). Input equalization should be used for long
traces or cables.
Table 3. Output Preemphasis
OUTPE
PEA
PEB
OUTP/OUTM
OUTAP/OUTAM
OUTBP/OUTBM
0
X
X
0dB
X
X
1
X
X
3dB
X
X
X
0
X
X
0dB
X
X
1
X
X
3dB
X
X
X
0
X
X
0dB
X
X
1
X
X
3dB
X = Don’t care.
10 SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
INEQ
EQA
EQB
INP/INM
INAP/INAM
INBP/INBM
X
0
X
X
0dB
X
1
X
X
4dB
X
X
X
0
X
X
0dB
X
X
1
X
X
4dB
X
X
X
0
X
X
0dB
X
X
1
X
X
4dB
MODEA
MODEB
INP/INM
INAP/INAM
INBP/INBM
0
X
X
SAS
X
X
1
X
X
SATA
X
X
X = Don’t care.
Table 5. OOB Mode Select
MODE
X
0
X
X
SAS
X
X
1
X
X
SATA
X
X
X
0
X
X
SAS
X
X
1
X
X
SATA
OUTAP/OUTAM
OUTBP/OUTBM
X = Don’t care.
Table 6. Output Amplitude Selection
OAMP
OAMPA
OAMPB
OUTP/OUTM
0
X
X
HIGH*
X
X
1
X
X
LOW*
X
X
X
0
X
X
HIGH*
X
X
1
X
X
LOW*
X
X
X
0
X
X
HIGH*
X
X
1
X
X
LOW*
X = Don’t care.
*See the Electrical Characteristics table.
SAS/SATA Mode Inputs
(MODE, MODEA, MODEB)
The MAX4986 supports both SAS and SATA OOB levels.
When MODE, MODEA, or MODEB are driven low or left
unconnected, the corresponding input’s OOB threshold
is 120mVP-P (min) (SAS mode). When MODE, MODEA,
or MODEB are driven high, the corresponding input’s
OOB threshold is 50mVP-P (min) (SATA mode). Signals
below the OOB threshold are squelched to prevent
unwanted noise from being redriven at the output. See
Table 5. MODE, MODEA, and MODEB have internal pulldown resistors of 330kI (typ).
Output Amplitude Selection Inputs
(OAMP, OAMPA, OAMPB)
The MAX4986 features independent output amplitude
selection. When OAMP, OAMPA, or OAMPB are driven
high, the corresponding output amplitude is low. When
OAMP, OAMPA, or OAMPB are driven low or left unconnected, the corresponding output amplitude is high.
See Table 6. OAMP, OAMPA, and OAMPB have internal
pulldown resistors of 330kI (typ).
11
MAX4986
Table 4. Input Equalization
MAX4986
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
Typical Application Circuits
INA
Rx
INB
OUT
SEL1
GPIO
HOST B
SEL2
Tx
OUTA
Rx
OUTB
CONNECTOR
Tx
SAS
DRIVE
MAX4986
CONNECTOR
HOST A
MAIN BOARD
IN
EN
MIDPLANE (FR4)
NOTE: TWO HOSTS SHARING A SINGLE SAS DRIVE WITH CABLE-DETECT.
MAIN BOARD
Tx
CONNECTOR
MAX4986
OUTA
IN
EN
GPIO
SEL2
CONNECTOR
SEL1
HOST
INA
Rx
SAS
DRIVE A
CONNECTOR
OUTB
OUT
INB
SAS
DRIVE B
MIDPLANE (FR4)
NOTE: SINGLE HOST WITH TWO SAS DRIVES AND CABLE-DETECT.
Applications Information
Layout
Circuit board layout and design can significantly affect
the performance of the MAX4986. Use good, high-frequency design techniques, including minimizing ground
inductance and using controlled impedance transmission lines on data signals. It is recommended to place
1FF and 0.01FF power-supply bypass capacitors in
parallel as close to VCC as possible for each VCC pin.
Always connect VCC to a power plane.
12 Exposed-Pad Package
The exposed-pad, 42-pin TQFN package incorporates
features that provide a very low-thermal resistance
path for heat removal from the IC. The exposed pad
on the MAX4986 must be soldered to the circuit board
ground plane for proper thermal performance. For
more information on exposed-pad packages, refer
to Maxim Application Note 862: HFAN-08.1: Thermal
Considerations of QFN and Other Exposed-Paddle
Packages.
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
Proper power-supply sequencing is recommended for
all devices. Always apply GND then VCC before applying signals, especially if the signal is not current-limited.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
42 TQFN-EP
T423590+1
21-0181
90-0078
13
MAX4986
Power-Supply Sequencing
Caution: Do not exceed the absolute maximum ratings because stresses beyond the listed ratings may
cause permanent damage to the device.
SAS/SATA Single Lane 2:1/1:2 Multiplexer/
Demultiplexer Plus Redriver with Equalization
MAX4986
Revision History
REVISION
NUMBER
REVISION
DATE
0
1/10
Initial release
1
7/12
Added MAX4986ETO+ to data sheet
DESCRIPTION
PAGES
CHANGED
—
1, 2, 3
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. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
14
© Maxim Integrated Products, Inc. 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
2012 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.