Maxim Integrated MAX4888A User Manual

General Description

The MAX4888A/MAX4889A high-speed passive switches route PCI Express®(PCIe) data between two possible destinations. The MAX4888A is a quad single-pole/double-throw (4 x SPDT) switch ideally suited for switching two half lanes of PCIe data between two destinations. The MAX4889A is an octal single-pole/double-throw (8 x SPDT) switch ideal for switching four half lanes of PCIe data between four destinations. The MAX4888A/ MAX4889A feature a single digital control input (SEL) to switch signal paths.

The MAX4888A/MAX4889A are fully specified to operate from a single +3.0V to +3.6V power supply††. The MAX4888A is available in a 3.5mm x 5.5mm, 28-pin TQFN package. The MAX4889A is available in a 3.5mm x 9.0mm, 42-pin TQFN package. Both devices operate over the -40°C to +85°C temperature range.

Features

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

♦ Low Same-Pair Skew of 7ps

♦ Low 120µA (Max) Quiescent Current

♦ Supports PCIe Gen I and Gen || Data Rates

♦ Flow-Through Pin Configuration for Ease of

Layout

♦ Industry-Compatible Pinout

♦ Lead-Free Packaging

Applications

Desktop Computers

Servers/Storage Area Networks

Laptops

MAX4888A/MAX4889A

5.0Gbps PCI Express Passive Switches

________________________________________________________________

Maxim Integrated Products

1

Pin Configurations

19-0770; Rev 2; 5/09

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.

EVALUATION KIT

AVAILABLE

Typical Application Circuit appears at end of data sheet.

††

Contact factory if operating at +2.5V or +1.8V.

PCI Express is a registered trademark of PCI-SIG Corp.

PART TEMP RANGE PIN-PACKAGE CONFIGURATION

MAX4 888AETI+ -40°C to +85°C 28 TQFN-EP* Two Half Lanes

MAX4889AETO+ -40°C to +85°C 42 TQFN-EP* Four Half Lanes

Ordering Information/Selector Guide

+

Denotes lead(Pb)-free/RoHS-compliant package.

*

EP = Exposed paddle.

TOP VIEW

NO2-

NO2+

NO1-

NO1+

V+

GND

NC2-

NC2+

NC1-

NC1+

24 23 22 21 20 19 18 17 16 15

N.C.

14

13

12

11

GND

V+

GND

V+

25

GND

26

V+

*EP

SEL

MAX4888A

N.C.

COM1+

COM1-

27

GND

28

V+

+

12345678910

GND

COM2+

V+

COM2-

TQFN

*CONNECT EXPOSED PADDLE TO GROUND.

NC4+

NC4-

COM3-

NO3+

V+

GND

NC3-

NC3+

V+

NO2-

NO2+

NO1-

NO1+

NC2-

NC2+

NC1-

NC1+

38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22

39

GND

40

V+

41

GND

V+

*EP

42

+

1234567891011121314151617

COM1+

COM1-

GND

V+

COM2+

COM2-

MAX4889A

V+

SEL

GND

COM3+

TQFN

NO3-

COM4+

NO4+

COM4-

NO4-

21

20

19

18

GND

V+

GND

V+

MAX4888A/MAX4889A

5.0Gbps PCI Express Passive Switches

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V+ = +3.0V to +3.6V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V+ = +3.3V, TA= +25°C.) (Note 2)

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.

(All voltages referenced to GND, unless otherwise noted.)

V+ .............................................................................-0.3V to +4V

SEL, COM__, NO__, NC__ (Note 1) .............-0.3V to (V+ + 0.3V)

| COM__ - NO__ |, | COM__ - NC__ | (Note 1).................0 to +2V

Continuous Current (COM_ to NO__/NC__) .....................±70mA

Peak Current (COM__ to NO__/NC__)

(pulsed at 1ms, 10% duty cycle)..................................±70mA

Continuous Current (SEL).................................................±30mA

Peak Current (SEL)

(pulsed at 1ms, 10% duty cycle)................................±150mA

Continuous Power Dissipation (T

A

= +70°C)

28-Pin TQFN (derate 20.8mW/°C above +70°C) ....1666.7mW

42-Pin TQFN (derate 35.7mW/°C above +70°C) ....2857.1mW

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Junction Temperature......................................................+150°C

Note 1: Signals on SEL, NO__, NC__ or COM__ exceeding V+ or GND are clamped by internal diodes. Limit forward-diode current

to maximum current rating.

ANALOG SW ITCH

Analog-Signal Range

Voltage Between COM and NO/NC

On-Resistance R

On-Resistance Match Between Pairs of Same Channel

On-Resistance Match Between Channels

On-Resistance Flatness R

NO_ or NC_ Off-Leakage Current

COM_ On-Leakage Current

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

,

V

COM_

V

NO_, VNC_

| V

COM_

V

NO_

| V

COM_

V

NC_

ON

R

FLAT(ON)

I

NO_(OFF)

I

NC_(OFF)

I

COM_(ON)

(V+ - 1.2) V

-

| ,

0 1.8 V

-

|

ON

V+ = +3.0V, I V

or V

NO_

NC_

V+ = +3.0V, I V

or V

NO_

NC_

V+ = +3.0V, I V

or V

NO_

NC_

V+ = +3.0V, I V

or V

NO_

NC_

V+ = +3.6V, V

or V

V

NO_

NC_

V+ = +3.6V, V

or V

V

NO_

NC_

= 15mA,

COM_

= 0V, +1.8V

= 15mA,

COM_

= 0V (Notes 3, 4)

= 15mA,

COM_

= 0V (Notes 3, 4)

= 15mA

COM_

= 0V, +1.8V (Notes 4, 5)

= 0V, +1.8V,

COM_

= +1.8V, 0V

= 0V, +1.8V,

COM_

= V

or unconnected

COM_

7 

0.1 1 

0.6 2 

0.06 2 

-1 +1 μA

MAX4888A/MAX4889A

5.0Gbps PCI Express Passive Switches

_______________________________________________________________________________________ 3

Note 2: All units are 100% production tested at TA= +85°C. Limits over the operating temperature range are guaranteed by design

and characterization and are not production tested.

Note 3: ΔR

ON

= R

ON(MAX)

- R

ON(MIN)

.

Note 4: Guaranteed by design. Not production tested. Note 5: Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured over the

specified analog signal range.

ELECTRICAL CHARACTERISTICS (continued)

(V+ = +3.0V to +3.6V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V+ = +3.3V, TA= +25°C.) (Note 2)

DYNAMIC

Turn-On Time tON V

Turn-Off Time t

Propagation De la y tPD RS = RL = 50, unbalanced, Figure 2 50 ps

Output Skew Between Pairs t

Output Skew Between Same Pair

On-Los s G

Crosstalk V

Signaling Data Rate BR RS = RL = 50 5.0 Gbps

Off-Isolation V

NO_/NC_ Off-Capacitance

COM_ On-Capacitance C

LOGI C I N PU T

Input-Logic Low VIL 0.5 V

Input-Logic High VIH 1.4 V

Input-Logic H ysteresis V

Input Leakage Current IIN V

POW ER SUPPL Y

Power-Supply Range V+ 1.65 3.60 V

V+ Supply Current I+ V

Input Leakage Current IIN V

ESD PROTECTION

COM_+, COM_- Human Body Model ±6 kV

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

or V

NO_

V

OFF

SK1

t

SK2

LOS

CT1

ISO

C

NO_ /NC_(OFF) Figure 4 1 pF

COM_(ON)

100 mV

HYST

or V

NO_

RS = RL = 50, unbalanced; skew between any two pairs, Figure 2

RS = RL = 50, unbalanced; skew between two lines on same pair, Figure 2

RS = RL = 50, unbalanced, Figure 3

Crosstalk between any two pairs, R

= RL = 50,

S

unbalanced, Figure 3

Signal = 0dBm, R

= RL = 50,

S

Figure 3

Figure 4 2 pF

= 0V or V+ -1 +1 μA

SEL

= 0V or V+

SEL

= 0V or V+ -1 +1 μA

SEL

= +1.0V, RL = 50, Figure 1 90 250 ns

NC_

= +1.0V, RL = 50, Figure 1 10 50 ns

NC_

50 ps

10 ps

1MHz < f < 100MHz -0.5

500MHz < f < 1.25GHz -1.4

f = 50MHz -53

f = 1.25GHz -32

f = 10MHz -56

f = 1.25GHz -26

MAX4888A 60

MAX4889A 120

dB

μA

MAX4888A/MAX4889A

5.0Gbps PCI Express Passive Switches

4 _______________________________________________________________________________________

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

10.0

9.5

9.0

8.5

8.0

(Ω)

7.5

ON

R

7.0

6.5

6.0

5.5

5.0

-0.1 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

V+ = +1.8V

V+ = +2.5V

(V)

V

COM_

V+ = +3.3V

ON-RESISTANCE vs. V

COM_

MAX4888A/89A toc01

ON-RESISTANCE vs. V

(V+ = +1.8V)

14

12

10

8

(Ω)

ON

R

6

4

2

0

-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 V

TA = +25°C

TA = -40°C

(V)

COM_

TA = +85°C

COM_

MAX4888A/89A toc02

(Ω)

ON

R

14

12

10

ON-RESISTANCE vs. V

TA = +25°C

8

6

4

2

0

-0.1 0.1 0.3 0.5 0.7 0.9 1.1 1.3

(V+ = +2.5V)

V

(V)

COM_

TA = +85°C

MAX4888A/89A toc03

TA = -40°C

14

12

10

8

(Ω)

ON

R

6

4

2

0

-0.1 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

(V+ = +3.3V)

TA = +25°C

V

COM_

ON-RESISTANCE vs. V

COM_

TA = +85°C

MAX4888A/89A toc04

TA = -40°C

(V)

SUPPLY CURRENT vs. TEMPERATURE

80

70

60

50

40

30

SUPPLY CURRENT (μA)

20

10

0

-40 -15 10 35 60 85

TURN-ON/-OFF TIME vs. SUPPLY VOLTAGE

240 220 200 180 160 140

(ns)

120

OFF

/t

100

ON

NC_ tON

t

80 60

NO_ t

40 20

0

1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6

(MAX4889A)

V+ = +3.3V

V+ = +2.5V

V+ = +1.8V

TEMPERATURE (°C)

NO_ t

OFF

NC_ t

SUPPLY VOLTAGE (V)

OFF

LOGIC THRESHOLD vs. SUPPLY VOLTAGE

1.2

1.1

MAX4888A/89A toc05

1.0

0.9

0.8

LOGIC THRESHOLD (V)

0.7

0.6

0.5

ON

MAX4888A/89A toc07

V

IH

V

IL

1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 SUPPLY VOLTAGE (V)

MAX4888A/89A toc06

MAX4888A/MAX4889A

5.0Gbps PCI Express Passive Switches

_______________________________________________________________________________________ 5

Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

EYE DIAGRAM

(V+ = +1.8V, f = 1.25GHz,

PRBS SIGNAL, RS = RL = 50Ω)†

P-P

50ps/div

*PRBS = PSEUDORANDOM BIT SEQUENCE †

= GEN 1, 2.5Gbps; U1 = 400ps

V

COM_+

50mV/div

V

COM_-

600mV

EYE DIAGRAM

(V+ = +1.8V, f = 2.5GHz,

PRBS SIGNAL, RS = RL = 50Ω)

P-P

V

COM_+

600mV

MAX4888A/89A toc08

††

EYE DIAGRAM

(V+ = +3.3V, f = 1.25GHz,

PRBS SIGNAL, RS = RL = 50Ω)

P-P

50ps/div

*PRBS = PSEUDORANDOM BIT SEQUENCE †

= GEN 1, 2.5Gbps; U1 = 400ps

EYE DIAGRAM

(V+ = +3.3V, f = 2.5GHz,

PRBS SIGNAL, RS = RL = 50Ω)

P-P

V

COM_+

50mV/div

V

COM_-

V

COM_+

EYE DIAGRAM

(V+ = +2.5V, f = 1.25GHz,

600mV

PRBS SIGNAL, RS = RL = 50Ω)

P-P

50ps/div

*PRBS = PSEUDORANDOM BIT SEQUENCE †

= GEN 1, 2.5Gbps; U1 = 400ps

EYE DIAGRAM

(V+ = +2.5V, f = 2.5GHz,

600mV

PRBS SIGNAL, RS = RL = 50Ω)

P-P

†

MAX4888A/89A toc09

††

V

COM_+

50mV/div

V

COM_-

V

COM_+

600mV

†

MAX4888A/89A toc10

††

50mV/div

V

COM_-

25ps/div

*PRBS = PSEUDORANDOM BIT SEQUENCE ††

= GEN 11, 5.0Gbps; U1 = 200ps

MAX4888A/89A toc11

50mV/div

V

COM_-

25ps/div

*PRBS = PSEUDORANDOM BIT SEQUENCE ††

= GEN 11, 5.0Gbps; U1 = 200ps

MAX4888A/89A toc12

50mV/div

V

COM_-

25ps/div

*PRBS = PSEUDORANDOM BIT SEQUENCE ††

= GEN 11, 5.0Gbps; U1 = 200ps

MAX4888A/89A toc12

Maxim Integrated MAX4888A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual