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General Description
The MAX4927 meets the needs of high-speed differential switching, including that of Gigabit Ethernet
(10/100/1000) Base-T switching as well as LVDS and
LVPECL switching. The MAX4927 provides enhanced
ESD protection up to ±15kV and excellent high-frequency response, making the device especially useful for
interfaces that must go to an outside connection.
The MAX4927 offers extremely low capacitance (C
ON
),
as well as low on-resistance (R
ON
), for low-insertion
loss and very wide bandwidth. In addition to the four
pairs of DPDT switches, the MAX4927 provides LED
switching for laptop computer/docking station use.
The MAX4927 is pin-to-pin equivalent to the PI3L500-A
and STMUX1000L. The MAX4927 can replace either
device in those applications, improving ESD protection
and eliminating external ESD components. The
MAX4927 is available in a space-saving 56-pin TQFN
package and operates over the extended -40°C to
+85°C temperature range.
Applications
Notebooks and Docking Stations
Servers and Routers with Ethernet Interfaces
Board-Level Redundancy Protection
SONET/SDH Signal Routing
T3/E3 Redundancy Protection
LVDS and LVPECL Switching
Features
♦ ESD Protection
±15kV–IEC 61000-4-2 Air-Gap Discharge
±8kV–IEC 61000-4-2 Contact Discharge
±15kV–Human Body Model
♦ Single +3.0V to +3.6V Power-Supply Voltage
♦ Low 4Ω (typ), 6.5Ω (max) On-Resistance (R
ON
)
♦ Ultra-Low 8pF (typ) On-Capacitance (C
ON
)
♦ -23dB Return Loss (100MHz)
♦ -3dB Bandwidth: 650MHz
♦ Optimized Pin Out for Easy Transformer and PHY
Interface
♦ Built-In LED Switches for Switching Indicators to
Docking Station
♦ Low 450µA (max) Quiescent Current
♦ Bidirectional 8 to 16 Multiplexer/Demultiplexer
♦ Standard Pin Out, Matching the P13L500-A and
STMUX1000L
♦ Space-Saving Lead-Free Package
56-Pin, 5mm x 11mm, TQFN Package
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-0841; Rev 0; 6/07
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.
+Denotes lead-free package.
Note: All devices are specified over the -40°C to +85°C operating
temperature range.
*EP = Exposed pad.
Typical Operating Circuit and Functional Diagrams appear
at end of data sheet.
Pin Configuration
PINPACKAGE
LED
SWITCHES
PKG
CODE
TOP VIEW
GND
V
DD
2LED2
2LED1
GND
LED2
GND
V
DD
*CONNECT EXPOSED PADDLE TO GND OR
LEAVE EXPOSED PADDLE UNCONNECTED.
0B2
1B1
0B1
48 47 46 45 44 43
49
50
51
52
53
54
55
56
1+2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
A1
A0
GND
PART
DD
4B1
5B1
4B2
V
GND
1B2
DD
V
40 39 38 37 36 35 34 33 32 31 30 29
42 41
MAX4927
DD
A3
A2
N.C.
GND
A4
V
GND
TQFN
5mm x 11mm
A5
A6
GND
3B2
2B2
3B1
2B1
GND
7B1
6B2
7B2
6B1
GND
5B2
28
GND
27
V
DD
26
1LED2
25
0LED2
GND
24
1LED1
23
0LED1
22
*EP
GND
21
DD
A7
SEL
V
GND
LED0
LED1
MAX4927ETN+ 56 TQFN-EP* 3 T56511-1
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
VDD………………………………………………………-0.3V to +4V
All Other Pins…………………………………-0.3V to (V
DD
+ 0.3V)
Continuous Current (A_ to _B_) ......................................±120mA
Continuous Current (LED_ to _LED_) .…………………… ±40mA
Peak Current (A_ to _B_)
(pulsed at 1ms, 10% duty cycle) ……………………. ±240mA
Current into Any Other Pin................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
56-Pin TQFN (derate 40.9mW/°C above +70°C) .......5278mW
Operating Temperature Range …………………. -40°C to +85°C
Junction Temperature.……………………………………. +150°C
Storage Temperature Range .…………………. -65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(VDD= +3V to +3.6V, TA= TJ= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VDD= 3.3V, TA= +25°C.) (Note 1)
)
)
)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ANALOG SWITCH
On-Resistance R
ON
VDD = 3V,
= -40mA,
I
A_
V
= 0, 1.5V, 3V
A_
TA = +25°C 4 5.5
to T
T
MIN
MAX
6.5
Ω
On-Resistance Match
Between Switch Pairs
(Note 2)
On-Resistance Flatness R
FLAT(ON
On-Resistance LED Switches R
Off-Leakage Current I
On-Leakage Current I
LA_(OFF
LA_(ON
ESD PROTECTION
ESD Protection
SWITCH AC PERFORMANCE
Insertion Loss I
Return Loss R
Crosstalk
VDD = 3V,
ΔR
ON
I
A_
V
A_
VDD = 3V, IA_ = -40mA, V
ONLEDV D D
VDD = 3.6V, VA_ = 0.3V, 3.3V;
V
_B1
VDD = 3.6V, VA_ = 0.3V, 3.3V;
V
_B1
IEC 61000-4-2 Air-Gap Discharge ±15
IEC 61000-4-2 Contact Discharge ±8
Human Body Model (spec MIL-STD-883,
Method 3015)
RS = RL = 50Ω, unbalanced, f = 1MHz
(Note 2)
f = 100MHz -23 dB
Any switch to any
switch; R
50Ω, unbalanced,
Figure 1
V
V
LOS
LOS
CT1
CT2
= -40mA,
= 0, 1.5V, 3V
= 3V , I
_LE D _
or V
or V
= 3.3V, 0.3V
_B2
= 0.3V, 3.3V, or floating
_B2
= RL =
S
TA = +25°C 0.5 1.5
to T
T
MIN
MAX
= 1.5V, 3V 0.01 Ω
A_
= - 40m A, V
= 0, 1.5V , 3V 40 Ω
LE D _
-1 +1 µA
-1 +1 µA
f = 25MHz -50
f = 100MHz -26
2
Ω
kV
±15
0.6 dB
dB
MAX4927
1000 Base-T ±15kV ESD Protection LAN Switch
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD= +3V to +3.6V, TA= TJ= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VDD= 3.3V, TA= +25°C.) (Note 1)
Note 1: Specifications at TA= -40°C are guaranteed by design.
Note 2: Guaranteed by design.
Figure 1. Single-Ended Bandwidth, Crosstalk, and Off-Isolation
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SWITCH AC CHARACTERISTICS
-3dB Bandwidth BW RS = RL = 50Ω, unbalanced 650 MHz
Off-Capacitance C
On-Capacitance C
Turn-On Time t
Turn-Off Time t
Propagation Delay t
Output Skew Between Ports t
SWITCH LOGIC
Input-Voltage Low V
Input-Voltage High V
Input-Logic Hysteresis V
Input Leakage Current I
Operating-Supply Voltage Range V
Quiescent Supply Current I
PLH, tPHLRS
OFF
ON
ON
OFF
f = 1MHz, _B_, A_ 3.5 pF
f = 1MHz, _B_, A_ 6.5 pF
= 1V, R
V
A_
= 100Ω, Figure 2 50 ns
L
VA_ = 1V, RL = 100Ω, Figure 2 50 ns
= RL = 50Ω, unbalanced, Figure 3 0.15 ns
SK(o)
HYST
SEL
DD
DD
Skew between any two ports, Figure 4 0.01 ns
VDD = 3.0V 0.8 V
IL
VDD = 3.6V 2.0 V
IH
VDD = 3.3V 100 mV
VDD = 3.6V, V
SEL
= 0V or V
DD
-1 +1 µA
3.0 3.6 V
VDD = 3.6V, V
SEL
= 0V or V
DD
280 450 µA
SINGLE-ENDED BANDWIDTH
NETWORK
ANALYZER
SINGLE-ENDED CROSSTALK
NETWORK
ANALYZER
NETWORK
ANALYZER
SINGLE-ENDED OFF-ISOLATION
NETWORK
ANALYZER
50Ω TRACE
50Ω TRACE
50Ω TRACE
50Ω TRACE
R15
49.9Ω
MAX4927
56 TQFN
A0
2
A2
7
A3
8
A4
11
0B1
48
2B1
43
4B1
37
SEL
17
3B1
42
V
DD
50Ω TRACE
R13
49.9Ω
R14
49.9Ω
OR 0V
50Ω TRACE
NETWORK
ANALYZER
NETWORK
ANALYZER
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
4 _______________________________________________________________________________________
Figure 2. Turn-On and Turn-Off Times
Figure 3. Propagation Delay Times
Figure 4. Output Skew
SEL
50%
t
ON
50%
t
OFF
50%
A_
t
t
OFF
ON
50%
50%
50%
_B1
t
PHLX
t
3.0V
2.0V
1.0V
PHLY
V
2.0V
V
OH
OL
V
OH
2.0V
V
OL
V
IH
V
IL
0V
_B2
0V
3.0V
2.0V
1.0V
A_
t
PLHX
_B_
t
PLHY
_B_
OUTPUT SKEW = t
THE MAX4927 SWITCHES ARE FULLY BIDIRECTIONAL.
SK(O)
= |t
PLHY
- t
| OR |t
PLHX
PHLY
- t
|
PHLX
t
PLH
_B_
PULSE SKEW = t
THE MAX4927 SWITCHES ARE FULLY BIDIRECTIONAL.
SK(p)
= |t
PHL
- t
|
PLH
t
PHL
V
H
2.0V
V
L
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
_______________________________________________________________________________________ 5
Typical Operating Characteristics
(VDD= 3.3V, TA= +25°C, unless otherwise noted.)
ON-RESISTANCE vs. V
6
5
4
(Ω)
R
TA = +85°C
3
ON
2
1
0
0 1.0 2.0 3.0
TA = +25°C
QUIESCENT SUPPLY CURRENT (μA)
TA = -40°C
VA_ (V)
340
320
300
280
260
240
220
200
-40 -15 10 35 60 85
A_
MAX4927 toc01
24
22
20
18
16
14
(Ω)
12
ONLED
R
10
8
6
4
2
0
01.0
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
VDD = 3.6V
TEMPERATURE (°C)
LED_ ON-RESISTANCE vs. V
TA = +85°C
TA = +25°C
TA = -40°C
0.5
1.5 2.0 2.5 3.0
V
(V)
LED_
MAX4927 toc04
LED_
MAX4927 toc02
LEAKAGE CURRENT vs. TEMPERATURE
1500
1200
900
600
LEAKAGE CURRENT (pA)
300
0
-40 10-15 35 60 85
SINGLE-ENDED INSERTION LOSS
vs. FREQUENCY
0
-1
-2
-3
-4
-5
-6
-7
INSERTION LOSS (dB)
-8
-9
-10
1 1000
FREQUENCY (MHz)
10010
MAX4927 toc03
ILA_(ON)
ILA_(OFF)
TEMPERATURE (°C)
MAX4927 toc05
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
6 _______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1, 6, 9, 13, 16,
21, 24, 28, 33,
39, 44, 49, 53,
55
2 A0 Switch 0. Common terminal 0.
3 A1 Switch 1. Common terminal 1.
4, 10, 18, 27,
38, 50, 56
5 N.C. No Connection. Not internally connected.
7 A2 Switch 2. Common terminal 2.
8 A3 Switch 3. Common terminal 3.
11 A4 Switch 4. Common terminal 4.
12 A5 Switch 5. Common terminal 5.
14 A6 Switch 6. Common terminal 6.
15 A7 Switch 7. Common terminal 7.
17 SEL Select Input. SEL selects switch connection. See the truth table (Table 1).
19 LED0 LED0 Input
20 LED1 LED1 Input
22 0LED1 0LED1 Output. Drive SEL low (SEL = 0) to connect LED0 to 0LED1.
23 1LED1 1LED1 Output. Drive SEL low (SEL = 0) to connect LED1 to 1LED1.
25 0LED2 0LED2 Output. Drive SEL high (SEL = 1) to connect LED0 to 0LED2.
26 1LED2 1LED2 Output. Drive SEL high (SEL = 1) to connect LED1 to 1LED2.
29 7B2 Switch 7. Normally open terminal 7.
30 6B2 Switch 6. Normally open terminal 6.
31 7B1 Switch 7. Normally closed terminal 7.
32 6B1 Switch 6. Normally closed terminal 6.
34 5B2 Switch 5. Normally open terminal 5.
35 4B2 Switch 4. Normally open terminal 4.
36 5B1 Switch 5. Normally closed terminal 5.
37 4B1 Switch 4. Normally closed terminal 4.
40 3B2 Switch 3. Normally open terminal 3.
41 2B2 Switch 2. Normally open terminal 2.
42 3B1 Switch 3. Normally closed terminal 3.
43 2B1 Switch 2. Normally closed terminal 2.
45 1B2 Switch 1. Normally open terminal 1.
46 0B2 Switch 0. Normally open terminal 0.
47 1B1 Switch 1. Normally closed terminal 1.
48 0B1 Switch 0. Normally closed terminal 0.
GND Ground
V
DD
Positive-Supply Voltage Input. Bypass VDD to GND with a 0.1µF ceramic capacitor
(see the Power-Supply Bypassing section).
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
_______________________________________________________________________________________ 7
Detailed Description
The MAX4927 is a high-speed analog switch targeted
for 1000 Base-T applications. In a typical application,
the MAX4927 switches the signals from two separate
interface transformers and connects the signals to a
single 1000 Base-T Ethernet PHY (see the Typical
Operating Circuit). This configuration simplifies dockingstation design by avoiding signal reflections associated
with unterminated transmission lines in a T configuration. The MAX4927 is protected against ±15kV electrostatic discharge (ESD) events. The MAX4927 also
includes LED switches that allow the LED output signals to be routed to a docking station along with the
Ethernet signals. See the Functional Diagrams.
With its low resistance and capacitance, as well as high
ESD protection, the MAX4927 can be used to switch
most low-voltage differential signals, such as LVDS,
SERDES, and LVPECL, as long as the signals do not
exceed maximum ratings of the device.
The MAX4927 switch provides an extremely low capacitance and on-resistance to meet Ethernet insertion and
return-loss specifications. The MAX4927 features three
built-in LED switches.
The MAX4927 incorporates a unique architecture design
utilizing only n-channel switches within the main Ethernet
switch, reducing I/O capacitance and channel resistance. An internal two-stage charge pump with a nominal 7.5V output provides the high voltage needed to
drive the gates of the n-channel switches while maintaining a consistently low RONthroughout the input signal
range. An internal bandgap reference set to 1.23V and
an internal oscillator running at 2.5MHz provide proper
charge-pump operation. Unlike other charge-pump circuits, the MAX4927 includes internal flyback capacitors,
reducing design time, board space, and cost.
Digital Control Inputs
The MAX4927 provides a single digital control input,
SEL. SEL controls the high-frequency switches as well
as the LED switches as shown in Table 1.
Analog Signal Levels
The on-resistance of the MAX4927 is very low and stable as the analog input signals are swept from ground
to VDD(see the Typical Operating Characteristics). The
switches are bidirectional, allowing A_ and _B_ to be
configured as either inputs or outputs.
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electrostatic discharges encountered during handling and
assembly. All the high-frequency switch inputs (A_,
_B_), LED switch inputs (LED_, _LED_), and SEL have
high ESD protection against static electricity. Maxim’s
engineers have developed state-of-the-art structures to
protect these pins against ESD of ±15kV without damage. After an ESD event, the MAX4927 keeps working
without latchup or damage.
ESD protection can be tested in various ways. All signal
and control inputs of the MAX4927 are characterized
for protection to the following limits:
• ±15kV using the Human Body Model
• ±8kV using the Contact Discharge Method specified
in IEC 61000-4-2
• ±15kV using the Air-Gap Discharge Method specified
in IEC 61000-4-2
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Pin Description (continued)
Table 1. Truth Table
PIN NAME FUNCTION
51 2LED2 2LED2 Output. Drive SEL high (SEL = 1) to connect LED2 to 2LED2.
52 2LED1 2LED1 Output. Drive SEL low (SEL = 0) to connect LED2 to 2LED1.
54 LED2 LED2 Input
EP EP Exposed Paddle. Connect EP to GND or leave EP unconnected.
SEL CONNECTION
0 A_ to _B1, LED_ to _LED1
1 A_ to _B2, LED_ to _LED2
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
8 _______________________________________________________________________________________
Human Body Model
Figure 5a shows the Human Body Model. Figure 5b
shows the current waveform it generates when discharged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the test device through
1.5kΩ resistor.
IEC 61000-4-2
The IEC 61000-4-2 standard covers ESD testing and
performance of finished equipment. However, it does
not specifically refer to integrated circuits. The MAX4927
helps equipment design to meet IEC 61000-4-2 without
the need for additional ESD-protected components.
The major difference between tests done using the
Human Body Model and IEC 61000-4-2 is higher peak
current in IEC 61000-4-2 because series resistance is
lower in the IEC 61000-4-2 model. Hence, the ESD withstand voltage measured to IEC 61000-4-2 is generally
lower than that measured using the Human Body
Model. Figure 5c shows the IEC 61000-4-2 model, and
Figure 5d shows the current waveform for IEC 61000-42 ESD Contact Discharge test.
Machine Model
The machine model for ESD tests all pins using a 200pF
storage capacitor and zero discharge resistance.
The objective is to emulate the stress caused when I/O
pins are contacted by handling equipment during test
and assembly.
The Air-Gap Discharge Method involves approaching the
device with a charged probe. The Contact Discharge
Method connects the probe to the device before the
probe is energized.
Applications Information
Typical Operating Circuit
The Typical Operating Circuit shows the MAX4927 in a
1000 Base-T docking station application.
Power-Supply Sequencing and
Overvoltage Protection
Caution: Do not exceed the absolute maximum ratings.
Stresses beyond the listed ratings may cause permanent damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply VDDbefore applying
analog signals, especially if the analog signal is not
current limited.
Power-Supply Bypassing
Bypass at least one VDDinput to ground with a 0.1µF or
larger ceramic capacitor as close to the device as possible. Use the smallest physical size possible for optimal
performance (0603 body size is recommended).
It is also recommended to bypass more than one V
DD
input. A good strategy is to bypass one VDDinput with
a 0.1µF capacitor, and at least a second VDDinput with
a 10nF capacitor (use 0603 or smaller physical size
ceramic capacitor).
Layout
High-speed switches require proper layout and design
procedures for optimum performance. Keep design-controlled-impedance PCB traces as short as possible.
Ensure that bypass capacitors are as close as possible
to the device. Use large ground planes where possible.
Chip Information
PROCESS: BiCMOS
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
_______________________________________________________________________________________ 9
Figure 5a. Human Body ESD Test Model
Figure 5b. Human Body Current Waveform
Figure 5c. ICE 61000-4-2 ESD Test Model
Figure 5d. IEC 61000-4-2 ESD Generator Current Waveform
HIGH-
VOLTAGE
DC
SOURCE
R
C
Ω
1M
CHARGE-CURRENT-
LIMIT RESISTOR
C
100pF
s
R
D
Ω
1500
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
AMPS
IP 100%
90%
36.8%
10%
0
0
t
RL
I
r
TIME
t
DL
CURRENT WAVEFORM
DEVICE
UNDER
TEST
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
HIGH-
VOLTAGE
DC
SOURCE
R
C
50MΩ TO 100M
CHARGE-CURRENT-
LIMIT RESISTOR
C
s
150pF
Ω
R
D
Ω
330
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
I
100%
90%
PEAK
I
10%
tr = 0.7ns TO 1ns
30ns
60ns
DEVICE
UNDER
TEST
t
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
10 ______________________________________________________________________________________
Typical Operating Circuit
DOCKING STATION
TRANSFORMER
NOTEBOOK
ETHERNET
PHY/MAC
LED_OUT
TRD0_P
TRD0_N
TRD1_P
TRD1_N
TRD2_P
TRD2_N
TRD3_P
TRD3_N
A0
A1
A2
A3
A4
A5
A6
A7
LED_
MAX4927
SEL
_LED2
_LED1
0B2
1B2
2B2
3B2
4B2
5B2
6B2
7B2
0B1
1B1
2B1
3B1
4B1
5B1
6B1
7B1
RJ-45
LED
CONNECTOR
TRANSFORMER
RJ-45
SEL_DOCK
LED
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
______________________________________________________________________________________ 11
Functional Diagram
LED0
LED1
LED2
SEL
A0
A1
A2
A3
A4
A5
A6
A7
0B1
1B1
0B2
1B2
2B1
3B1
2B2
3B2
4B1
5B1
4B2
5B2
6B1
7B1
6B2
7B2
0LED1
0LED2
1LED1
1LED2
2LED1
2LED2
MAX4927
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
12 ______________________________________________________________________________________
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
.)
THIN QFN.EPS
MAX4927
1000 Base-T, ±15kV ESD Protection LAN Switch
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
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
.)
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