MAXIM MAX4890E, MAX4892E User Manual

现货库存、技术资料、百科信息、热点资讯，精彩尽在鼎好!

General Description

The MAX4890E/MAX4892E meet the needs of high-speed
differential switching. The devices handle the needs of
Gigabit Ethernet (10/100/1000) Base-T switching as
well as LVDS and LVPECL switching. The MAX4890E/
MAX4892E provide enhanced ESD protection up to
±15kV, and excellent high-frequency response, making
the devices especially useful for interfaces that must go to
an outside connection.

Both devices provide extremely low capacitance
(CON), as well as low resistance (RON), for low-insertion
loss and very wide bandwidth. In addition to the four
pairs of DPDT switches, the MAX4892E provides LED
switching for laptop computer/docking station use.

The MAX4890E/MAX4892E are pin-for-pin equivalents
to the MAX4890/MAX4892 and can replace these
devices for those applications requiring the enhanced
ESD protection. Both devices are available in space­saving TQFN packages and operate over the standard

-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

♦ ±15kV ESD Protected Per MIL-STD-883, Method

3015

♦ Single +3.0V to +3.6V Power-Supply Voltage

♦ Low On-Resistance (RON): 4Ω (typ), 6.5Ω (max)

♦ Ultra-Low On-Capacitance (CON): 8pF (typ)

♦ -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 (MAX4892E)

♦ Low 450µA (max) Quiescent Current

♦ Bidirectional 8 to 16 Multiplexer/Demultiplexer

♦ Standard Pin Out, Matching the MAX4890 and

MAX4892

♦ Space-Saving Lead-Free Packages

32-Pin, 5mm x 5mm, TQFN Package
36-Pin, 6mm x 6mm, TQFN Package

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-0624; Rev 0; 8/06

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.

PART

PIN­PACKAGE

LED

PKG

CODE

MAX4890EETJ+

—

T-3255-4

MAX4892EETX+

3

T-3666-3

+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.

Eye Diagram

CH2: 4B2, 100mV/div

CH1: 5B2, 100mV/div

f = 125MHz

Pin Configurations

SEL
2B1

2B2
3B2

4B2

5B2

4B1
5B1

3B1

A3

LED0

0LED1

A4
A5
A6

A1

1

2

3

4

5

6

7

8

9

101112131415161718

363534333231302928

27

26

25

24

23

22

21

20

19

1LED2

7B2

6B2

6B1

1LED1

LED1

GND

A7

MAX4892E

TOP VIEW

0LED2

7B1

A2

A0

0B2

V+

LED2

2LED1

2LED2

0B1

1B1

1B2

TQFN

*EP

*EXPOSED PAD CONNECTED TO GND.

+

Pin Configurations continued at end of data sheet.

SWITCHES

32 TQFN-EP*

36 TQFN-EP*

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

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.

V+ ……………………………………………………… -0.3V to +4V
All Other Pins………………………………….. -0.3V to (V+ + 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)
32-Pin TQFN (derate 34.5mW/°C above +70°C) …….. 2.76W
36-Pin TQFN (derate 35.7mW/°C above +70°C) …….. 2.85W

ESD Protection, Human Body Model .............................±15kV

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

(V+ = +3V to +3.6V, TA= TJ= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at V+ = 3.3V, TA= +25°C.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

ANALOG SWITCH

TA = +25°C 4 5.5

On-Resistance R

ON

V+ = 3V,
I

A_

= -40mA,

V

A_

= 0, 1.5V, 3V

T

MIN

to T

MAX

6.5

Ω

On-Resistance LED Switches

(MAX4892E)

40 Ω

TA = +25°C 0.5 1.5

On-Resistance Match
Between Channels

∆R

ON

V+ = 3V,
I

A_

= -40mA,

V

A_

= 0, 1.5V, 3V

(Note 2)

T

MIN

to T

MAX

2

Ω

On-Resistance Flatness

)

V+ = 3V, IA_ = -40mA, V

A_

= 1.5V, 3V

Ω

Off-Leakage Current

)

V+ = 3.6V, VA_ = 0.3V, 3.3V;
V

_B1

or V

_B2

= 3.3V, 0.3V

-1 +1

On-Leakage Current

)

V+ = 3.6V, VA_= 0.3V, 3.3V;
V

_B1

or V

_B2

= 0.3V, 3.3V or floating

-1 +1

µA

ESD PROTECTION

ESD Protection

Human Body Model (spec MIL-STD-883,
Method 3015)

kV

SWITCH AC PERFORMANCE

Insertion Loss I

LOS

RS = RL = 50Ω, unbalanced, f = 1MHz,
(Note 2)

0.6 dB

Return Loss R

LOS

f = 100MHz -23 dB

R

ONLED

R

FLAT(ON

I

LA_(OFF

I

LA_(ON

V + = 3V , I

_L E D _

= - 40m A, V

= 0, 1.5V , 3V

LE D _

0.01

±15

MAX4890E/MAX4892E

1000 Base-T ±15kV ESD Protection LAN Switch

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(V+ = +3V to +3.6V, TA= TJ= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at V+ = 3.3V, TA= +25°C.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

V

CT1

f = 25MHz -50

Crosstalk

V

CT2

Any switch to any
switch; R

S

= RL =
50Ω, unbalanced,
Figure 1

f = 125MHz -26

dB

SWITCH AC CHARACTERISTIC

-3dB Bandwidth BW RS = RL = 50Ω, unbalanced

MHz

Off-Capacitance C

OFF

f = 1MHz, _B_, A_ 3.5 pF

On-Capacitance C

ON

f = 1MHz, _B_, A_ 6.5 pF

Turn-On Time t

ON

V

A_

= 1V, R

L

, 100Ω, Figure 2 50 ns

Turn-Off Time t

OFF

VA_ = 1V, RL, 100Ω, Figure 2 50 ns

Propagation Delay

RS = RL = 50Ω, unbalanced, Figure 3 0.1 ns

Output Skew Between Ports t

SK(o)

Skew between any two ports, Figure 4

ns

SWITCH LOGIC

Input-Voltage Low V

IL

V+ = 3.0V 0.8

Input-Voltage High V

IH

V+ = 3.6V 2.0

V

Input-Logic Hysteresis V

HYST

V+ = 3.3V

mV

Input Leakage Current I

SEL

V+ = 3.6V, V

SEL

= 0 or V+ -5 +5 µA

Operating Supply-Voltage Range

V+ 3.0 3.6 V

Quiescent Supply Current I+ V+ = 3.6V, V

SEL

= 0 or V+

µA

Note 1: Specifications at -40°C are guaranteed by design.
Note 2: Guaranteed by design.

t

PLH, tPHL

650

0.01

100

280 450

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

4 _______________________________________________________________________________________

0

2

1

4

3

5

6

0 1.0 1.50.5 2.0 2.5 3.0

ON-RESISTANCE vs. V

A_

MAX4890E toc01

VA_ (V)

R

ON

(Ω)

TA = +85°C

TA = +25°C

TA = -40°C

0

8

10

12

14

6

2

4

16

18

22
20

24

01.0

0.5

1.5 2.0 2.5 3.0

LED_ON-RESISTANCE vs. V

LED_

MAX4890E toc02

V

LED_

(V)

R

ONLED

(Ω)

TA = +85°C

TA = +25°C

TA = -40°C

0

12

8

4

16

20

24

28

32

36

40

-40 10-15 35 60 85

LEAKAGE CURRENT vs. TEMPERATURE

MAX4890E toc03

TEMPERATURE (°C)

LEAKAGE CURRENT (pA)

ILA_(ON)

ILA_(OFF)

200

220

240

260

280

300

320

340

-40 -15 10 35 60 85

QUIESCENT SUPPLY CURRENT

vs. TEMPERATURE

MAX4890E toc04

TEMPERATURE (°C)

QUIESCENT SUPPLY CURRENT (µA)

V+ = 3.6V

SINGLE-ENDED INSERTION LOSS

vs. FREQUENCY

MAX4890E toc05

FREQUENCY (MHz)

INSERTION LOSS (dB)

10010

-7

-6

-5

-4

-3

-2

-1

0

-8
1 1000

Typical Operating Characteristics

(V+ = 3.3V, TA= +25°C, unless otherwise noted.)

MAX4890E/MAX4892E

1000 Base-T ±15kV ESD Protection LAN Switch

_______________________________________________________________________________________ 5

Pin Description

PIN

MAX4892E

NAME FUNCTION

1 32 A1 Differential PHY Interface Pair. Connect to the Ethernet PHY.

2 1 A2 Differential PHY Interface Pair. Connect to the Ethernet PHY.

3 2 A3 Differential PHY Interface Pair. Connect to the Ethernet PHY.

4 — LED0 LED0 Input

5 — 0LED1 0LED1 Output. Drive SEL low (SEL = 0) to connect LED0 to 0LED1.

6 — 0LED2 0LED2 Output. Drive SEL high (SEL = 1) to connect LED0 to 0LED2.

7 7 A4 Differential PHY Interface Pair. Connect to the Ethernet PHY.

8 8 A5 Differential PHY Interface Pair. Connect to the Ethernet PHY.

9 9 A6 Differential PHY Interface Pair. Connect to the Ethernet PHY.

10 10 A7 Differential PHY Interface Pair. Connect to the Ethernet PHY.

11 11 GND Ground

12 — LED1 LED1 Input

13 — 1LED1 1LED1 Output. Drive SEL low (SEL = 0) to connect LED1 to 1LED1.

14 — 1LED2 1LED2 Output. Drive SEL high (SEL = 1) to connect LED1 to 1LED2.

15 13 7B2 B2 Differential Pair

16 14 6B2 B2 Differential Pair

17 15 7B1 B1 Differential Pair

18 16 6B1 B1 Differential Pair

19 17 5B2 B2 Differential Pair

20 18 4B2 B2 Differential Pair

21 19 5B1 B1 Differential Pair

22 20 4B1 B1 Differential Pair

23 21 3B2 B2 Differential Pair

24 22 2B2 B2 Differential Pair

25 23 3B1 B1 Differential Pair

26 24 2B1 B1 Differential Pair

27 29 SEL Select Input. SEL selects switch connection. See the Truth Table (Table1).

28 25 1B2 B2 Differential Pair

29 26 0B2 B2 Differential Pair

30 27 1B1 B1 Differential Pair

31 28 0B1 B1 Differential Pair

32 — 2LED2 2LED2 Output. Drive SEL high (SEL = 1) to connect LED2 to 2LED2.

33 — 2LED1 2LED1 Output. Drive SEL low (SEL = 0) to connect LED2 to 2LED1.

34 — LED2 LED2 Input

35 30 V+ Positive-Supply Voltage Input. Bypass to GND with a 0.1µF ceramic capacitor.

36 31 A0 Differential PHY Interface Pair. Connect to the Ethernet PHY.

— 3-6, 12 N.C. No Connection. Not internally connected.

——EP Exposed Pad. Connect exposed pad to GND or leave it unconnected.

MAX4890E

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

6 _______________________________________________________________________________________

Detailed Description

The MAX4890E/MAX4892E are high-speed analog
switches targeted for 1000 Base-T applications. In a
typical application, the MAX4890E/MAX4892E switch
the signals from two separate interface transformers
and connect the signals to a single 1000 Base-T
Ethernet PHY (see the Typical Operating Circuit). This
configuration simplifies docking station design by
avoiding signal reflections associated with unterminat­ed transmission lines in a T configuration. The
MAX4890E/MAX4892E are protected against ±15kV
electrostatic discharge (ESD) shocks. The MAX4892E
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 their low resistance and capacitance, as well as
high ESD protection, the MAX4890E/MAX4892E can be
used to switch most low-voltage differential signals,

such as LVDS, SEREDES, and LVPECL, as long as the
signals do not exceed maximum ratings of the devices.

The MAX4890E/MAX4892E switches provide an
extremely low capacitance and on-resistance to meet
Ethernet insertion and return-loss specifications. The
MAX4892E features three built-in LED switches.

The MAX4890E/MAX4892E incorporate 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 output of 7.5V 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 MAX4890E/MAX4892E
include internal flyback capacitors, reducing design
time, board space, and cost.

R15

49.9Ω

NETWORK
ANALYZER

NETWORK
ANALYZER

NETWORK
ANALYZER

NETWORK

ANALYZER

SINGLE-ENDED BANDWIDTH

50Ω TRACE

SINGLE-ENDED CROSSTALK

50Ω TRACE

SINGLE-ENDED OFF-ISOLATION

50Ω TRACE

50Ω TRACE

A0
36

A2
2

A3
3

A4
7

4B1
22

3B1
25

2B1
26

0B1
31

50Ω TRACE

NETWORK
ANALYZER

NETWORK
ANALYZER

50Ω TRACE

R14

49.9Ω

R13

49.9Ω

MAX4892E

36 TQFN

Figure 1. Single-Ended Bandwidth, Crosstalk, and Off-Isolation

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

_______________________________________________________________________________________ 7

Digital Control Inputs

The MAX4890E/MAX4892E provide a single digital con­trol SEL. SEL controls the switches as well as the LED
switches as shown in Table 1.

Analog Signal Levels

The on-resistance of the MAX4890E/MAX4892E is very
low and stable as the analog input signals are swept
from ground to V+ (see the Typical Operating
Characteristics). The switches are bidirectional, allow­ing A_ and _B_ to be configured as either inputs or out­puts.

ESD Protection

The MAX4890E/MAX4892E are characterized using the
Human Body Model for ±15kV of ESD protection. Figure 5
shows the Human Body Model. This model consists of a
100pF capacitor charged to the ESD voltage of interest
which is then discharged into the test device through a

1.5kΩ resistor. All signal and control pins are ESD pro­tected to ±15kV HBM (Human Body Model).

Applications Information

Typical Operating Circuit

The Typical Operating Circuit shows the MAX4890E/
MAX4892E 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 V+ before applying
analog signals, especially if the analog signal is not
current limited.

Layout

High-speed switches require proper layout and design
procedures for optimum performance. Keep design-con­trolled-impedance pc board 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

SEL CONNECTION

0 A_ to _B1, LED_ to _LED1

1 A_ to _B2, LED_ to _LED2

Table 1. Truth Table

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

8 _______________________________________________________________________________________

V

IH

V

IL

50%

_B1

t

OFF

0V

t

ON

0V

_B2

t

ON

50%

50%

50%

50%

t

OFF

50%

SEL

Figure 2. Turn-On and Turn-Off Times

2.0V

3.0V

1.0V

THE MAX4890E/MAX4892E SWITCHES ARE FULLY BIDIRECTIONAL.

t

PHL

V

H

V

L

2.0V

t

PLH

A_

_B_

PULSE SKEW = t

SK(p)

= |t

PHL

- t

PLH

|

Figure 3. Propagation Delay Times

2.0V

3.0V

1.0V

THE MAX4890E/MAX4892E SWITCHES ARE FULLY BIDIRECTIONAL.

t

PHLX

V

OH

V

OL

2.0V

t

PLHX

A_

_B_

OUTPUT SKEW = t

SK(O)

= |t

PLHY

- t

PLHX

| OR |t

PHLY

- t

PHLX

|

t

PHLY

V

OH

V

OL

2.0V

t

PLHY

_B_

Figure 4. Output Skew

CHARGE-CURRENT

LIMIT RESISTOR

DISCHARGE
RESISTANCE

STORAGE
CAPACITOR

C

s

100pF

R

C

1MΩ

R

D

1500Ω

HIGH-

VOLTAGE

DC

SOURCE

DEVICE
UNDER

TEST

Figure 5. Human Body ESD Test Model (MIL-STD-883, Method 3015)

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

_______________________________________________________________________________________ 9

NOTEBOOK

DOCKING STATION

ETHERNET
PHY/MAC

TRD0_P

TRD0_N

TRD1_P

TRD1_N

TRD2_P

TRD2_N

TRD3_P

TRD3_N

A0
A1

A2
A3

A4
A5

A6
A7

SEL_DOCK

SEL

_LED2

6B2
7B2

4B2
5B2

2B2
3B2

0B2
1B2

LED_

_LED1

0B1
1B1

2B1
3B1

4B1
5B1

6B1
7B1

LED_OUT

RJ-45

TRANSFORMER

TRANSFORMER

LED

CONNECTOR

RJ-45

LED

MAX4892E

Typical Operating Circuit

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

10 ______________________________________________________________________________________

Functional Diagrams

0B1
1B1

0B2

1B2

2B1

3B1

2B2

3B2

6B2

7B2

6B1

7B1

4B2

5B2

4B1

5B1

A0
A1

A2

A3

A4

A5

A6

A7

SEL

MAX4890E

0B1
1B1

0B2

1B2

2B1

3B1

2B2

3B2

6B2

7B2

6B1

7B1

4B2

5B2

4B1

5B1

A0
A1

A2

A3

A4

A5

A6

A7

SEL

MAX4892E

LED0

0LED1
0LED2

LED1

LED2

1LED1
1LED2

2LED1
2LED2

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

______________________________________________________________________________________ 11

Pin Configurations (continued)

32 31 30 29 28 27 26

9 101112131415

18

19

20

21

22

23

24

7

6

5

4

3

2

1

MAX4890E

TQFN

TOP VIEW

A3

A2

N.C.

N.C.

N.C.

N.C.

A4

8

A5

A1

A0

V+

SEL

0B1

1B1

0B2

25

1B2

2B1

3B1

2B2

3B2

4B1

5B1

4B2

17

5B2

7B1

6B2

16

6B1

7B2

N.C.

GND

A7

A6

*EP

*EXPOSED PADDLE CONNECTED TO GND.

+

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

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

.)

QFN THIN.EPS

MAX4890E/MAX4892E

1000 Base-T, ±15kV ESD Protection LAN Switches

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

© 2006 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

.)

QFN THIN.EPS