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MAX14978

SuperSpeed USB Passive Switch

(Low/Full/Hi/SuperSpeed)

19-5573; Rev 1; 4/11

Typical Operating Circuit

General Description

The MAX14978 high-performance, passive analog switch

is ideal for switching Hi-Speed USB and SuperSpeed USB

data between one source and two loads, or vice versa. The

device can be used in desktop and notebook applications

where SuperSpeed USB ports are in limited supply. The

device consists of two sets of analog switches with one

set used for USB low-speed, full-speed, and Hi-Speed

signals and the second set used for USB SuperSpeed.

The device operates from a single +3.3V supply.

The device features low insertion loss for all speeds. It

has Q6kV Human Body Model (HBM) ESD protection

on all I/O pins. In addition, the low/full/Hi-Speed COM_

ports have ESD protection to Q15kV HBM and Q8kV IEC

61000-4-2 contact.

The device is available in a small, 3.5mm x 9.0mm,

42-pin TQFN package and is specified over the extend-

ed -40NC to +85NC temperature range.

Applications

Desktop PCs

Laptop PCs

Industrial USB Switching

Features

S Designed for SuperSpeed USB Applications:

Low/Full/Hi-Speed (1.5/12/480Mbps)

SuperSpeed (5.0Gbps)

S Superior Return Loss and Insertion Loss for

SuperSpeed Analog Switches

S Low Quiescent Current: 36µA (typ)

S All Link Training is Preserved (SuperSpeed)

S LVCMOS Control (1.4V P V

P 3.6V)

S Operation from a Single +3.3V Power Supply

S Small, 3.5mm x 9.0mm, 42-Pin TQFN Package

Ordering Information

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

*EP = Exposed pad.

MAX14978

SEL1 SEL2

GND

+3.3V

NCD+

NCD-

D+

SUPERSPEED

USB

PORT1

USB SWITCH

CONTROLLER

D-

Tx+

Tx-

Rx+

Rx-

D+

SUPERSPEED

USB

CONTROLLER

D-

Tx+

Tx-

Rx+

Rx-

D+

SUPERSPEED

USB

PORT2

D-

Tx+

Tx-

Rx+

Rx-

NOD+

NOD-

COMD+

0.1µF

COMD-

COM0+

COM0-

COM1+

COM1-

NC0+

NC0-

NC1+

NC1-

NO0+

NO0-

NO1+

NO1-EN

PART TEMP RANGE PIN-PACKAGE

MAX14978ETO+

-40NC to +85NC

42 TQFN-EP*

Summary of content (15 pages)

PAGE 1
9-5573; Rev 1; 4/11 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) Features The MAX14978 high-performance, passive analog switch is ideal for switching Hi-Speed USB and SuperSpeed USB data between one source and two loads, or vice versa. The device can be used in desktop and notebook applications where SuperSpeed USB ports are in limited supply.
PAGE 2
MAX14978 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND, unless otherwise noted.) VCC. ......................................................................-0.3V to +6.0V VDD. ......................................................................-0.3V to +4.0V SEL1, EN, COMD_, NOD_, NCD_ (Note 1)....................................... -0.3V to (VCC + 0.3V) SEL2, COM0_, COM1_, NC0_, NC1_, NO0_, NO1_ (Note 1)................ -0.3V to (VDD + 0.
PAGE 3
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) (VCC = +3.0V to +5.5V, VDD = +3.0V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = VDD = +3.3V, TA = +25NC.) (Note 2) PARAMETER SYMBOL On-Resistance Match Between Channels DRON On-Resistance Match Between Pairs of Same Channels DRON On-Resistance Flatness Off-Leakage Current On-Leakage Current RFLAT ICOM(OFF) ICOM(ON) CONDITIONS TYP MAX Hi-Speed USB switches, VCC = 3.0V, VCOMD_ = 2.0V (Notes 4, 5) 0.
PAGE 4
MAX14978 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) ELECTRICAL CHARACTERISTICS (continued) (VCC = +3.0V to +5.5V, VDD = +3.0V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = VDD = +3.3V, TA = +25NC.
PAGE 5
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) (VCC = +3.0V to +5.5V, VDD = +3.0V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = VDD = +3.3V, TA = +25NC.) (Note 2) PARAMETER Fault-Protection Recovery Time NO_ or NC_ Off-Capacitance COM_ Off-Capacitance COM_ On-Capacitance SYMBOL tFPR CNO(OFF) or CNC(OFF) CCOM(OFF) CONDITIONS MIN TYP Hi-Speed USB switches, VCOMD_ = 5V to 0V step, RL = RS = 50I, VCC = 3.
PAGE 6
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) MAX14978 Test Circuits/Timing Diagrams 0.1µF VCC VDD 0.1µF V OFF-ISOLATION = 20log OUT VIN NETWORK ANALYZER 0V OR VDD SEL_ VCC VDD NC_ MAX14978 V ON-LOSS = 20log OUT VIN 50Ω MEAS VOUT NO_ 50Ω 50Ω VIN COM_ V CROSSTALK = 20log OUT VIN REF 50Ω 50Ω GND MEASUREMENTS ARE STANDARDIZED AGAINST SHORTS AT IC TERMINALS. OFF-ISOLATION IS MEASURED BETWEEN COM_ AND "OFF" NO_ OR NC_ TERMINAL ON EACH SWITCH.
PAGE 7
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) 0.1µF VDD VCC 0.1µF VDD VCC IN+ RS MAX14978 NO_+ OR NC_+ COM_+ OUT+ RISE-TIME PROPAGATION DELAY = tPLHX OR tPLHY FALL-TIME PROPAGATION DELAY = tPHLX OR tPHLY RL IN- RS NO_- OR NC_- COM_- tSK1 = DIFFERENCE IN PROPAGATION DELAY (RISE-FALL) BETWEEN ANY TWO PAIRS tSK2 = | tPLHX - tPHLY | OR | tPHLX - tPLHY | BETWEEN TWO LINES ON THE SAME PAIR OUTRL SEL_ tINFALL tINRISE +1.5V 90% VIN+ 50% 90% 50% 10% 0V 10% +1.
PAGE 8
MAX14978 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) Test Circuits/Timing Diagrams (continued) VDD VCC VDD COM_ VCC 0.1µF +5V VCC = +3.3V 0.1µF +3V VCOMD_ 0V MAX14978 tFPR tFP SEL_ CAPACITANCE METER VFP +3V VNOD_ VIL OR VIH NC_ OR NO_ GND VNCD_ 0V Figure 4. Fault Protection Response/Recovery Time Figure 5. Channel Off-/On-Capacitance Typical Operating Characteristics (VCC = VDD = 3.3V, TA = +25NC, unless otherwise noted.) 10.0 Uls: 9995/9995 9.5 400 8.5 200 8.
PAGE 9
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) SUPERSPEED HI-SPEED SWITCHES SUPPLY CURRENT vs. TEMPERATURE 30 20 0.9 0.8 VIL 0.7 10 35 TEMPERATURE (°C) 60 85 70 60 COM_ ON-LEAKAGE 50 40 30 20 COM_ OFF-LEAKAGE 10 0 10 35 60 4 3 2 1 0 85 0 1 TEMPERATURE (°C) MAX14978 toc06 3 LOW/FULL/HI-SPEED SWITCHES LOGIC-INPUT THRESHOLD vs. SUPPLY VOLTAGE 1.2 1.0 0.8 0.6 VIH VIL 0.4 2 0 3 2.8 3.8 LOGIC LEVEL (V) LOW/FULL/HI-SPEED SWITCHES FREQUENCY RESPONSE 0 -10 -20 2 0.
PAGE 10
MAX14978 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) Pin Configuration NO1- NO1+ NO0- NO0+ NC1- NC1+ NC0- NC0+ VDD NOD- NCD- EN VCC SEL1 N.C. NCD+ NOD+ TOP VIEW 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 GND N.C. 39 20 VDD MAX14978 N.C. 41 19 GND EP 7 8 9 N.C. N.C. COMD+ GND N.C. COMD- N.C. SEL2 18 VDD 10 11 12 13 14 15 16 17 COM1+ 6 GND 5 VDD 4 COM0- 3 COM0+ 2 GND 1 N.C. + COM1- N.C. 42 GND N.C.
PAGE 11
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) PIN NAME FUNCTION 33 EN Active-Low Enable Input for Hi-Speed USB Switches. Drive EN high to put Hi-Speed USB switches in high impedance. Drive EN low for normal operation. 34 VCC Positive-Supply Voltage Input for Hi-Speed USB Switches. Bypass VCC to GND with a 0.1FF ceramic capacitor as close as possible to the device.
PAGE 12
MAX14978 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) Detailed Description The MAX14978 is ideal for SuperSpeed USB and low/ full/Hi-Speed (1.5/12/480Mbps) USB switching applications. The low VIH threshold of the device permits it to be used with logic levels as low as 1.4V. The device’s Hi-Speed USB analog switches are based on a chargepump-assisted n-channel architecture and operate with 36FA (typ) quiescent current.
PAGE 13
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) Human Body Model Figure 6a shows the Human Body Model, and Figure 6b shows the current waveform it generates when discharged into a low-impedance state. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device through a 1.5kI resistor. IEC 61000-4-2 The main difference between tests done using the Human Body Model and IEC 61000-4-2 is higher peak current in IEC 61000-4-2.
PAGE 14
MAX14978 SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) Package Information Power-Supply Sequencing Caution: Do not exceed the absolute maximum ratings because stresses beyond the listed ratings may cause permanent damage to the device. Proper power-supply sequencing is recommended for all CMOS devices. Always apply VCC and VDD before applying analog signals, especially if the analog signals are not current limited.
PAGE 15
SuperSpeed USB Passive Switch (Low/Full/Hi/SuperSpeed) REVISION NUMBER REVISION DATE 0 9/10 Initial release — 1 4/11 Updated analog signal range specification in Electrical Characteristics 2 DESCRIPTION PAGES CHANGED 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.