MAXIM MAX4999ETJ

19-4127; Rev 0; 5/08
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
The MAX4999 differential Hi-Speed USB analog multiplexer features low on-capacitance (CON) 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 supporting data rates up to 480Mbps.
The MAX4999 is a differential 8:1 multiplexer. The
MAX4999 features three digital inputs to control the signal 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 minimum power consumption.
The MAX4999 operates from a +3.0V to +3.6V powersupply 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.
Applications
Keyboard, Video, Mouse (KVM)
Servers/RAID
Features
♦ Single +3.0V to +3.6V Power-Supply Voltage
♦ Low 6.5Ω (typ) On-Resistance (RON)
♦ -3dB Bandwidth: 1200MHz (typ)
♦ Enable Input Puts All Channels in HighImpedance State (Standby Mode)
♦ Low Operating Current (1µA) and Ultra-Low
Quiescent Current (30nA) in Standby Mode
♦ Low Threshold Eliminates the Need for
Translators in 1.8V Low-Voltage Systems
♦ Small 32-Pin, 5mm x 5mm, TQFN Package
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX4999ETJ+
-40°C to +85°C
32 TQFN-EP*
+Denotes a lead-free package.
*EP = Exposed pad.
Mass Storage
Workstations
VCC
D3_1
D3_0
GND
23
D4_1
24
GND
D4_0
TOP VIEW
GND
Pin Configuration
22
21
20
19
18
17
D5_1 25
16
D2_1
D5_0 26
15
D2_0
GND 27
14
GND
13
D1_1
12
D1_0
D6_1 28
MAX4999
D6_0 29
GND 30
*EP
D7_1 31
1
2
3
4
5
6
7
8
GND
VCC
EN
COM0
COM1
C0
C1
C2
D7_0 32
11
GND
10
D0_1
9
D0_0
TQFN
5mm x 5mm
*CONNECT EXPOSED PAD TO GND.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX4999
General Description
MAX4999
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
VCC ...........................................................................-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 (TA = +70°C)
32-Lead TQFN (derate 34.5mW/°C above +70°C) ....2759mW
Junction-to-Case Thermal Resistance (θJC) (Note 2)
32-Lead TQFN ............................................................2.0°C/W
Junction-to-Ambient Thermal Resistance (θJA) (Note 2)
32-Lead TQFN .............................................................29°C/W
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: Signals exceeding GND are clamped by internal diodes. Limit forward-diode current to maximum current rating.
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.
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.
ELECTRICAL CHARACTERISTICS
(VCC = +3.0V to +3.6V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
3.6
V
POWER SUPPLY
Supply Voltage
VCC
Quiescent Supply Current
IO
3.0
Charge pump on
5
Charge pump off
1
µA
ANALOG SWITCH
On-Resistance
RON
ICOM_ = ±10mA
6.5
12
Ω
On-Resistance Match
ΔRONSC
VCOM_ = 1V, TA = +25°C
0.8
Ω
On-Resistance Match Between
Channels
ΔRONBC
VCOM_ = 1V, TA = +25°C
1
Ω
+1
µA
Leakage Current COM_, D_0, D_1
IL
VCC = +3.6V
-1
SWITCH AC PERFORMANCE (Note 4)
Crosstalk
VDCT1
Any switch to non-paired switch at 500MHz
(Figure 3)
-30
dB
Off-Isolation
VOFF
Any switch to non-paired switch at 240MHz
(Figure 3)
-27
dB
1200
MHz
Bandwidth -3dB
BW
On-Capacitance
CON
Off-Capacitance
COFF
Propagation Delay
Turn-On Time
2
RL = 45Ω unbalanced (Figure 3)
f = 1MHz
Taken from S11 parameters at f = 240MHz
f = 1MHz, COM_
6
3.0
5
pF
pF
Taken from S11 parameters at f = 240MHz
3.0
tPD
RL = RS = 50Ω (Figure 2)
300
ps
tON
VD0 or VD1 = +1.5V, RL = 300Ω, CL = 35pF,
VIH = VCC, VIL = 0V (Figure 1)
10
µs
_______________________________________________________________________________________
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
(VCC = +3.0V to +3.6V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Turn-Off Time
tOFF
VD0 or VD1 = +1.5V, RL = 300Ω, CL = 35pF,
VIH = VCC, VIL = 0V (Figure 1)
10
µs
Output Skew Same Port
tPD
Skew between any D_0, D_1 line, same port
45Ω unbalanced I/O, f = 240MHz (Figure 2)
30
ps
Input Logic Low
VIL
VCC = +3.0V
Input Logic High
VIH
VCC = +3.6V
SWITCH LOGIC
Input Logic Hysteresis
VHYST
Input Leakage Current
ILEAK
0.6
1.7
V
200
VCC = +3.6V, VCOM_ = 0V or VCC
V
mV
-1
+1
µA
ESD PROTECTION
All Pins
Human Body Model
±2
kV
Note 3: All units are 100% production tested at TA = +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
VCC
MAX4999
VN_
LOGIC
INPUT
COM_
D0_
OR D1_
50%
VIL
VOUT
RL
t OFF
CL
C_
VOUT
GND
LOGIC
INPUT
SWITCH
OUTPUT
CL INCLUDES FIXTURE AND STRAY CAPACITANCE.
RL
VOUT = VN_
RL + RON
(
)
t R < 5ns
t F < 5ns
VIH
0.9 x V0UT
0.9 x VOUT
0V
t ON
IN DEPENDS ON SWITCH CONFIGURATION;
INPUT POLARITY DETERMINED BY SENSE OF SWITCH.
Figure 1. Switching Time
_______________________________________________________________________________________
3
MAX4999
ELECTRICAL CHARACTERISTICS
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
MAX4999
Test Circuits/Timing Diagrams (continued)
MAX4999
RS
IN+
D0_1
COM1
OUT+
RL
RS
IN-
D0_0
COM2
RISE-TIME PROPAGATION DELAY = tPLH.
FALL-TIME PROPAGATION DELAY = tPHL.
tSK = |tPLH - tPHL|.
RS = RL = 50Ω.
OUTRL
C0 C1 C2
VCC
VIN+
50%
50%
50%
50%
0V
V+
VIN0V
tPLH
tR
tPHL
VCC
tF
90%
VOUT+
90%
50%
50%
10%
0V
10%
VCC
50%
VOUT-
50%
0V
tPHL
tPLH
Figure 2. Propagation Delay and Skew
4
_______________________________________________________________________________________
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
VCC 0.1μF
VIN
V+
CHANNEL
SELECT
NETWORK
ANALYZER
50Ω
50Ω
D_ _
C0
C1
C2
ON-LOSS = 20log
MAX4999
VOUT
HIGH
EN
OFF-ISOLATION = 20log
COM_
MEAS.
REF.
CROSSTALK = 20log
GND
50Ω
VOUT
VIN
VOUT
VIN
VOUT
VIN
50Ω
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
MAX4999
Test Circuits/Timing Diagrams (continued)
Typical Operating Characteristics
(VCC = +3.3V, TA = +25°C, unless otherwise noted.)
RON (Ω)
RON (Ω)
6.0
5.4
5.2
TA = +25°C
5.5
TA = -40°C
5.0
5.0
VCC = +3.6V
0.6
1.2
1.8
2.4
3.0
2.2
LOGIC THRESHOLD
vs. SUPPLY VOLTAGE
0.88
0.75
60
-10
ON-RESPONSE
-20
-30
VIL
0.80
85
CROSSTALK
-40
-50
-60
-70
OFF-ISOLATION
-80
0.75
0.63
35
FREQUENCY RESPONSE
0.90
0.85
10
0
LOSS (dB)
1.00
VIH
0.95
-15
-40
MAX4999 toc05
1.00
LOGIC THRESHOLD (V)
VCC = +3.0V
COM OFF-LEAKAGE
TEMPERATURE (°C)
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
VCC = +3.6V
40
3.3
VCOM (V)
VCC = +3.3V
1.13
1.1
VCOM (V)
1.25
60
0
0
3.6
MAX4999 toc04
0
COM ON-LEAKAGE
80
20
4.0
4.6
VCC = +3.6V
100
4.5
4.8
MAX4999 toc03
6.5
5.6
120
MAX4999 toc06
VCC = +3.3V
TA = +85°C
LEAKAGE CURRENT (nA)
5.8
VCC = +3.3V
MAX4999 toc02
7.0
MAX4999 toc01
6.0
VCC = +3.0V
LEAKAGE CURRENT
vs. TEMPERATURE
ON-RESISTANCE
vs. VCOM
ON-RESISTANCE
vs. VCOM
QUIESCENT SUPPLY CURRENT (μA)
MAX4999
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
-90
-100
0.70
0.50
-40
-15
10
35
60
85
3.0
3.2
3.5
3.6
1
10
EYE DIAGRAM - SINGLE
MAX4999 toc07
100
FREQUENCY (MHz)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
6
3.3
EYE DIAGRAM - DOUBLE
MAX4999 toc08
_______________________________________________________________________________________
1000
10,000
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
PIN
NAME
FUNCTION
1, 11, 14, 17,
21, 24, 27, 30
GND
Ground
2, 20
3
VCC
EN
Power-Supply Input. Bypass VCC to GND with a 0.1µF capacitor placed as close to VCC as possible.
Enable Input
4
COM0
5
COM1
6
7
C0
C1
Control Input 0
Control Input 1
8
C2
Control Input 2
9
D0_0
Analog Switch 0 D- Terminal
10
12
D0_1
D1_0
Analog Switch 0 D+ Terminal
Analog Switch 1 D- Terminal
13
D1_1
Analog Switch 1 D+ Terminal
15
D2_0
Analog Switch 2 D- Terminal
16
18
D2_1
D3_0
Analog Switch 2 D+ Terminal
Analog Switch 3 D- Terminal
19
D3_1
Analog Switch 3 D+ Terminal
22
D4_1
Analog Switch 4 D+ Terminal
23
25
D4_0
D5_1
Analog Switch 4 D- Terminal
Analog Switch 5 D+ Terminal
26
D5_0
Analog Switch 5 D- Terminal
28
D6_1
Analog Switch 6 D+ Terminal
29
31
D6_0
D7_1
Analog Switch 6 D- Terminal
Analog Switch 7 D+ Terminal
32
D7_0
—
EP
Analog Switch Common D- Terminal
Analog Switch Common D+ Terminal
Analog Switch 7 D- Terminal
Exposed Pad. Connect EP to GND or leave unconnected.
Detailed Description
The MAX4999 differential Hi-Speed USB analog multiplexer features low on-capacitance (CON) and low onresistance (R ON ) necessary for high-performance
switching applications. The low CON is designed for
USB server/mass storage devices. This device is ideal
for USB 2.0 Hi-Speed applications at 480Mbps, while
also meeting the requirements for USB low-/full-speed
applications.
Digital Control Inputs (C0, C1, C2)
The MAX4999 provides three digital control inputs (C0,
C1, C2) to select the analog signal path between the
COM_ and D-/D+ channels. The truth table for the
MAX4999 is shown in the Functional Diagram/Truth
Table. Driving the control inputs rail-to-rail minimizes
power consumption.
Enable Input (EN)
The MAX4999 features an enable input that when driven
low, places the device in standby mode. In standby
mode, all channels are high impedance and the internal
charge pump is disabled, thus minimizing the quiescent
supply current. For normal operation, drive EN high.
Analog Signal Levels
Signals applied to COM1 are routed to D_ _1 terminals.
Signals applied to COM0 are routed to D_ _0 terminals.
This multiplexer is bidirectional, allowing COM_ and
D-/D+ terminals to be configured as either inputs or
outputs. Additionally, the MAX4999 can be used for
non-USB signals if the signals fall within the normal
operating range.
The MAX4999 features an internal charge pump that
allows signal levels greater than the supply voltage.
Limit the analog input/output signal level to no more
than the Absolute Maximum Ratings.
_______________________________________________________________________________________
7
MAX4999
Pin Description
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
MAX4999
Functional Diagram/Truth Table
Applications Information
Increasing USB Channels
VCC
MUX
D0 _1
D1 _1
D2 _1
D3 _1
D4 _1
D5 _1
D6 _1
D7 _1
MUX
D0 _0
D1 _0
D2 _0
D3 _0
D4 _0
D5 _0
D6 _0
D7 _0
MAX4999
COM1
COM0
The MAX4999 features an enable input that allows two
MAX4999s to be connected, allowing multiplexing
between 16 USB channels. Figure 4 shows the typical
application with a single USB common terminal multiplexed to eight channels (8:1). See the Eye Diagram Single graph in the Typical Operating Characteristics.
Figure 5 shows two MAX4999 devices configured with
the USB common terminal multiplexed to 16 USB channels (16:1). See the Eye Diagram - Double graph in the
Typical Operating Characteristics. The MAX4999 was
designed to be symmetrical so that the two common
ports may be wired in parallel with very short wiring to
create a 16:1 configuration. When operating in 16:1 configuration, interchange COM0 and COM1 on the second
device to reverse the D+ and D- pins. This minimizes
vias and crossovers (Figure 5).
USB Switching
The MAX4999 analog multiplexers are fully compliant
with the USB 2.0 specification. The low on-resistance
and low on-capacitance of the MAX4999 make it ideal
for high-performance switching applications.
Board Layout
EN
C0
CONTROL
LOGIC
C1
CHARGE
PUMP
C2
GND
Hi-Speed switches require proper layout and design procedures for optimum performance. Keep design-controlled impedance PCB traces as short as possible.
Ensure that high-quality bypass ceramic capacitors
(X7R, X5R or better) are placed as close to the device as
possible and use large ground planes where possible.
MAX4999
EN
C2
C1
C0
1
0
0
0
COM_→D0
1
0
0
1
COM_→D1
1
0
1
0
COM_→D2
1
0
1
1
COM_→D3
1
1
0
0
COM_→D4
1
1
0
1
COM_→D5
1
1
1
0
COM_→D6
1
1
1
1
COM_→D7
X
STANDBY MODE.
ALL SWITCHES IN HIGHIMPEDANCE STATE.
CHARGE PUMP IS OFF.
0
X
X
FUNCTION
X = DON’T CARE
8
_______________________________________________________________________________________
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
D5_1
D5_0
USB6
+
-
D6_1
D6_0
USB7
+
-
D7_1
D7_0
23 22
D3_0
D3_1
D4_0
D4_1
+
USB5
-
MAX4999
USB3
+ -
USB4
+ -
19 18
25
26
16
15
28
29
13
12
MAX4999
31
32
10
9
D2_1
+
USB2
-
D2_0
D1_1
+
USB1
-
D1_0
D0_1
+
USB0
-
D0_0
+3.3V
VCC
2, 20
4 5 3 6 7 8
1, 11, 14, 17,
21, 24, 27, 30
GND
EN C0 C1 C2
- +
COMMON
Figure 4. The MAX4999 Multiplexes Between Eight Differential Channels (8:1)
ONE PAIR SHOWN
+
-
C2 C1 C0 EN0
EN1
D20
16
15
+
1
8
7
6
MAX4999
DEVICE 0
3
5
4
3
4
5
6
7
8
1
+
MAX4999
DEVICE 1
15
16
D20
USB TYPE A
COMMON
+
-
USB D+, D- MUST BE REVERSED IF DEVICES ARE CONNECTED AS SHOWN,
THIS IS TRUE OF D0–D7. C0, C1, C2 ARE CONNECTED IN PARALLEL.
EN0 AND EN1 ARE USED TO SELECT BETWEEN DEVICE 0 AND DEVICE 1.
Figure 5. Combining Two MAX4999 Devices for 16:1 USB Connections
_______________________________________________________________________________________
9
MAX4999
USB 2.0 Hi-Speed Differential
8:1 Multiplexer
Package Information
Chip Information
PROCESS: CMOS
For the latest package outline information, go to
www.maxim-ic.com/packages.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
32 TQFN-EP
T3255-4
21-0140
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.
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is a registered trademark of Maxim Integrated Products, Inc.