19-4127; Rev 1; 6/11
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
General Description
The MAX4999 differential Hi-Speed USB analog multi-
plexer features low on-capacitance (C
ON
) switching,
making it an ideal solution for the USB server/mass
storage market. The MAX4999 is designed for USB 2.0
low-/full-/Hi-Speed applications with capability of sup-
porting data rates up to 480Mbps.
The MAX4999 is a differential 8:1 multiplexer. The
MAX4999 features three digital inputs to control the sig-
nal path. Typical applications include switching a USB
connector between eight USB hosts and a USB device.
An enable input (EN) is provided to disable all channels
and place the device into a high-impedance state
(standby mode), shutting off the charge pump for mini-
mum power consumption.
The MAX4999 operates from a +3.0V to +3.6V power-
supply voltage and is specified over the -40°C to +85°C
extended temperature range. The MAX4999 is available
in a 5mm x 5mm, 32-pin TQFN package.
o
Low 6.5Ω (typ) On-Resistance (R
ON
)
o
-3dB Bandwidth: 1200MHz (typ)
o
Enable Input Puts All Channels in High-
Impedance State (Standby Mode)
o
Low Operating Current (1µA) and Ultra-Low
Quiescent Current (30nA) in Standby Mode
o
Low Threshold Eliminates the Need for
Translators in 1.8V Low-Voltage Systems
o
Small 32-Pin, 5mm x 5mm, TQFN Package
Features
o
Single +3.0V to +3.6V Power-Supply Voltage
MAX4999
Ordering Information
PART
MAX4999ETJ+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
32 TQFN-EP*
Applications
Keyboard, Video, Mouse (KVM)
Servers/RAID
Mass Storage
Workstations
+Denotes
a lead-free package.
*EP
= Exposed pad.
Pin Configuration
D4_0
D4_1
D3_1
D3_0
18
GND
GND
V
CC
GND
17
16
15
14
13
D2_1
D2_0
GND
D1_1
D1_0
GND
D0_1
D0_0
12
11
*EP
10
9
1
GND
2
V
CC
3
EN
4
COM0
5
COM1
6
C0
7
C1
8
C2
TOP VIEW
24
D5_1 25
D5_0 26
GND 27
D6_1 28
D6_0 29
GND 30
D7_1 31
D7_0 32
23
22
21
20
19
MAX4999
TQFN
5mm x 5mm
*CONNECT EXPOSED PAD TO GND.
________________________________________________________________
Maxim Integrated Products
1
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.
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
MAX4999
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
CC
...........................................................................-0.3V to +4V
All Other Pins (Note 1)..............................................-0.3V to +4V
Continuous Current (COM_ to any switch) .......................±60mA
Peak Current (COM_ to any switch) (pulsed at 1ms,
10% duty cycle)..........................................................±120mA
Continuous Power Dissipation (T
A
= +70°C)
32-Lead TQFN (derate 34.5mW/°C above +70°C) ....2759mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Note 1:
Signals exceeding GND are clamped by internal diodes. Limit forward-diode current to maximum current rating.
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.
PACKAGE THERMAL CHARACTERISTICS (Note 2)
TQFN
Junction-to-Ambient Thermal Resistance (θ
JA
) ............29°C/W
Junction-to-Case Thermal Resistance (θ
JC
) ...............2.0°C/W
Note 2:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a
four-layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +3.6V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= +3.3V and T
A
= +25°C.) (Note 3)
PARAMETER
POWER SUPPLY
Supply Voltage
Quiescent Supply Current
ANALOG SWITCH
On-Resistance
On-Resistance Match
On-Resistance Match Between
Channels
Leakage Current COM_, D_ _0,
D_ _1
SWITCH AC PERFORMANCE (Note 4)
Crosstalk
Off-Isolation
Bandwidth -3dB
On-Capacitance
Off-Capacitance
Propagation Delay
Turn-On Time
V
DCT1
V
OFF
BW
C
ON
C
OFF
t
PD
t
ON
Any switch to non-paired switch at 500MHz
(Figure 3)
Any switch to non-paired switch at 240MHz
(Figure 3)
R
L
= 45Ω unbalanced (Figure 3)
f = 1MHz
Taken from S11 parameters at f = 240MHz
f = 1MHz, COM_
Taken from S11 parameters at f = 240MHz
R
L
= R
S
= 50Ω (Figure 2)
V
D_ _0
or V
D_ _1
= +1.5V, R
L
= 300Ω,
C
L
= 35pF, V
IH
= V
CC
, V
IL
= 0V (Figure 1)
-30
-27
1200
6
3.0
5
3.0
300
10
dB
dB
MHz
pF
pF
ps
µs
R
ON
∆R
ONSC
∆R
ONBC
I
L
I
COM_
= ±10mA
V
COM_
= 1V, T
A
= +25°C
V
COM_
= 1V, T
A
= +25°C
V
CC
= +3.6V
-1
6.5
12
0.8
1
+1
Ω
Ω
Ω
µA
V
CC
I
O
Charge pump on
Charge pump off
3.0
3.6
5
1
V
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +3.6V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= +3.3V and T
A
= +25°C.) (Note 3)
PARAMETER
Turn-Off Time
SYMBOL
t
OFF
CONDITIONS
V
D_ _0
or V
D_ _1
= +1.5V, R
L
= 300Ω, C
L
=
35pF, V
IH
= V
CC
, V
IL
= 0V (Figure 1)
Skew between any D_ _0, D_ _1 line, same
port 45Ω unbalanced I/O, f = 240MHz
(Figure 2)
MIN
TYP
10
MAX
UNITS
µs
MAX4999
Output Skew Same Port
SWITCH LOGIC
Input Logic Low
Input Logic High
Input Logic Hysteresis
Input Leakage Current
ESD PROTECTION
All Pins
t
PD
30
ps
V
IL
V
IH
V
HYST
I
LEAK
V
CC
= +3.0V
V
CC
= +3.6V
V
CC
= +3.6V, V
COM_
= 0V or V
CC
Human Body Model
1.7
200
-1
±2
0.6
V
V
mV
+1
µA
kV
Note 3:
All units are 100% production tested at T
A
= +85°C. Limits over the operating temperature range are guaranteed by design
and not production tested.
Note 4:
Guaranteed by design.
Test Circuits/Timing Diagrams
V
CC
t R < 5ns
t F < 5ns
MAX4999
V
IN
D_ _0
OR D_ _1
COM_
V
OUT
R
L
C_
LOGIC
INPUT
GND
C
L
LOGIC
INPUT
V
IH
50%
V
IL
t
OFF
V
OUT
0.9 x V
0UT
0.9 x V
OUT
SWITCH
OUTPUT
0V
t
ON
C
L
INCLUDES FIXTURE AND STRAY CAPACITANCE.
R
L
V
OUT
= V
IN
R
L
+ R
ON
(
)
IN DEPENDS ON SWITCH CONFIGURATION;
INPUT POLARITY DETERMINED BY SENSE OF SWITCH.
Figure 1. Switching Time
_______________________________________________________________________________________
3
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
MAX4999
Test Circuits/Timing Diagrams (continued)
MAX4999
R
S
IN+
D0_1
COM1
R
L
R
S
IN-
D0_0
OUT+
RISE-TIME PROPAGATION DELAY = t
PLH
.
FALL-TIME PROPAGATION DELAY = t
PHL
.
t
SK
= |t
PLH
- t
PHL
|.
R
S
= R
L
= 50Ω.
COM0
R
L
OUT-
C
0
C
1
C
2
V
CC
V
IN+
0V
V+
V
IN-
0V
t
R
90%
50%
0V
V
CC
V
OUT-
0V
t
PHL
t
PLH
50%
50%
50%
10%
10%
90%
t
F
50%
50%
50%
50%
t
PLH
V
CC
V
OUT+
t
PHL
Figure 2. Propagation Delay and Skew
4
_______________________________________________________________________________________
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
Test Circuits/Timing Diagrams (continued)
V
CC
0.1µF
NETWORK
ANALYZER
50Ω
50Ω
MAX4999
V+
CHANNEL
SELECT
C0
C1
C2
D_ _ _
VIN
OFF-ISOLATION = 20log
V
OUT
V
IN
V
OUT
V
IN
V
OUT
V
IN
MAX4999
VOUT
HIGH
EN
GND
50Ω
50Ω
COM_
MEAS.
REF.
ON-LOSS = 20log
CROSSTALK = 20log
MEASUREMENTS ARE STANDARDIZED AGAINST SHORT AT SOCKET TERMINALS.
OFF-ISOLATION IS MEASURED BETWEEN COM_ AND "OFF" USB_ TERMINAL ON EACH SWITCH.
ON-LOSS IS MEASURED BETWEEN COM_ AND "ON" USB_ TERMINAL ON EACH SWITCH.
CROSSTALK IS MEASURED FROM ONE USB_ CHANNEL TO ANOTHER USB_ CHANNEL.
SIGNAL DIRECTION THROUGH SWITCH IS REVERSED; WORST VALUES ARE RECORDED.
Figure 3. Off-Isolation, On-Loss, and Crosstalk
_______________________________________________________________________________________
5
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