LTM2884
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For more information www.linear.com/LTM2884
Typical applicaTion
FeaTures DescripTion
Isolated USB Transceiver
with Isolated Power
The LTM
®
2884 is a complete galvanically isolated USB
2.0 compatible μModule
®
(micromodule) transceiver.
An upstream supply powers both sides of the interface
through an integrated, isolated DC/DC converter.
The LTM2884 is ideal for isolation in host, hub, bus split-
ter or peripheral device applications. It is compatible with
USB 2.0 full speed (12Mbps) and low speed (1.5Mbps)
operation. Automatic speed selection configures integrated
pull-up resistors on the upstream port to match those
sensed on the downstream device.
The isolator µModule technology uses coupled inductors
and an isolated power transformer to provide 2500VRMS
of isolation between the upstream and downstream USB
interface. This device is ideal for systems requiring isolated
ground returns or large common mode voltage variations.
Uninterrupted communication is guaranteed for common
mode transients greater than 30kV/μs.
Enhanced ESD protection allows this part to withstand
up to ±15kV (human body model) on the USB transceiver
interface pins to local supplies and ±15kV through the
isolation barrier to supplies without latch-up or damage.
Powered 2.5W Isolated Hub Port
applicaTions
n Isolated USB Transceiver: 2500VRMS for 1 Minute
n UL-CSA Recognized File #E151738
n USB 2.0 Full Speed and Low Speed Compatible
n Integrated Isolated DC/DC Converter, External or
Bus Powered
n Auto-Configuration of Bus Speed
n 2.5W (500mA at 5V) Output Power from External
Input Supply (VCC = 8.6V to 16.5V)
n 1W (200mA at 5V) Output Power from USB Bus
Supply (VBUS)
n 3.3V LDO Output Supply Signal References VLO, VLO2
n High Common Mode Transient Immunity: 30kV/μs
n ESD: ±15kV HBM on USB Interface Pins
n 15mm × 15mm × 5mm Surface Mount BGA Package
n Isolated USB Interfaces
n Host, Hub, or Device Isolation
n Industrial/Medical Data Acquisition
L, LT, LT C , LT M , Linear Technology, the Linear logo and µModule are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
Bus Powered 1W Isolated Peripheral Device
2884 TA01a
ISOLATION BARRIER
VLO
LTM2884 500mA AT 5V
ON
4.4V TO 16.5V
VBUS
VBUS2
8.6V TO 16.5V
100µF
VCC
SPNDPWR
D1+
D1–
VCC2
VLO2
D2+
DOWNSTREAM
USB PORT
D2–
GND2GND
15k 15k
+
PWR
HUB
µC
2884 TA01b
VLO
ON
SPNDPWR
VCC2
VBUS
VBUS
GND
GND2GND
UPSTREAM
USB PORT
VCC
ISOLATION BARRIER
LTM2884
200mA AT 5V
D1+
PERIPHERAL
D1–
VLO2
D2+
D2–
PWR
1.5k
LTM2884
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For more information www.linear.com/LTM2884
pin conFiguraTionabsoluTe MaxiMuM raTings
Supply Voltages
VCC to GND ............................................ –0.3V to 18V
VBUS to GND .......................................... –0.3V to 18V
VCC2 to GND2 ....................................... –0.3V to 10V
VLO to GND .................................................. –0.3V to 4V
VLO2 to GND2 ............................................... –0.3V to 4V
ON, SPNDPWR to GND .................–0.3V to (VLO + 0.3V)
D1+, D1– to GND ........................................ –0.3V to 5.3V
D2+, D2– to GND2 ..................................... –0.3V to 5.3V
Operating Ambient Temperature Range (Note 3)
LTM2884C ............................................... 0°C to 70°C
LTM2884I ............................................–40°C to 85°C
LTM2884H ......................................... –40°C to 105°C
Storage Temperature Range .................. –55°C to 125°C
Maximum Internal Operating Temperature ............ 125°C
Peak Body Reflow Temperature ............................ 245°C
(Note 1)
BGA PACKAGE
44-LEAD (15mm × 15mm × 5mm)
TOP VIEW
21 43 5 6 7 8 9 1110
D1–D1+
SPND-
PWR
ON VLO VBUS VCC
GND
D2–D2+VLO2 VCC2
GND2
GND2
GND
GND2
F
G
H
L
J
K
E
A
B
C
D
TJMAX = 125°C,
PCB = JESD51-9 2s2p: θJA = 18.7°C/W, θJCtop = 16°C/W, θJCbottom = 5.7°C/W, θJB = 5.6°C/W
PCB = DC1746A: θJA = 33.5°C/W, θJCtop = 15.7°C/W, θJCbottom = 6.1°C/W, θJB = 5.3°C/W
HEAT FLOW: θJA = NORMAL, θJCtop = 100%, θJCbottom = 100%, θJB = 100%
WEIGHT = 2.4g
PART NUMBER PAD OR BALL FINISH
PART MARKING PACKAGE
TYPE
MSL
RATING TEMPERATURE RANGEDEVICE FINISH CODE
LTM2884CY#PBF
SAC305 (RoHS) LTM2884Y e1 BGA 4
0°C to 70°C
LTM2884IY#PBF –40°C to 85°C
LTM2884HY#PBF –40°C to 105°C
• Device temperature grade is indicated by a label on the shipping
container.
• Pad or ball finish code is per IPC/JEDEC J-STD-609.
• Terminal Finish Part Marking: www.linear.com/leadfree
• This product is not recommended for second side reflow. For more
information, go to: www.linear.com/BGA-assy
• Recommended BGA PCB Assembly and Manufacturing Procedures:
www.linear.com/BGA-assy
• BGA Package and T
ray Drawings: www.linear.com/packaging
• This product is moisture sensitive. For more information, go to:
www.linear.com/BGA-assy
orDer inForMaTion
http://www.linear.com/product/LTM2884#orderinfo
LTM2884
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For more information www.linear.com/LTM2884
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VBUS = 5V, GND = GND2 = 0V, ON = VLO, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply
VCC Operating Supply Range (Isolated Power Input) l4.4 12 16.5 V
VBUS Operating Supply Range (USB Bus Power Input) l4.4 5 16.5 V
VCC Supply Current Power Off ON = 0V, VCC = 4.4V to 16.5V l100 500 µA
ICC VCC Supply Current Power On ICC2 = 0mA, Figure 1 l50 100 mA
VBUS Supply Current Power Off ON = 0V l10 100 µA
IBUS VBUS Supply Current Power On IVLO = 0mA, Figure 1 l6 9 mA
VBUS Supply Current Suspend Mode SPNDPWR = 3.3V
USB Suspend Timeout
SPNDPWR = 0,
USB Suspend Timeout
l
l
1.5
500
2.0
µA
mA
VCC2 Regulated VCC2 Output Voltage, Loaded VCC = 4.4V, ICC2 = 200mA, Figure 1
VCC = 8.6V, ICC2 = 500mA, Figure 1
l
l
4.75
4.75
5
5
5.25
5.25
V
V
VCC2 Source Current High Power Mode VCC = 8.6V, Figure 1 l500 mA
VCC2 Source Current Bus Power Mode VCC = VBUS = 4.4V, Figure 1 l200 mA
VLO VLO Regulated Output Voltage IVLO = 0mA to 10mA, Figure 1 l3.15 3.3 3.45 V
VLO Output Voltage Maximum Current Figure 1 l10 mA
VLO2 VLO2 Regulated Output Voltage IVLO2 = 0mA to 10mA, Figure 1 l3.15 3.3 3.45 V
VLO2 Output Voltage Maximum Current Figure 1 l10 mA
USB Input Levels (D1+, D1–, D2+, D2–)
VIH Single-Ended Input High Voltage l2.0 V
VIL Single-Ended Input Low Voltage l0.8 V
VHYS Single-Ended Input Hysteresis 200 mV
VDIFF Differential Input Sensitivity |(D1+ – D1–)| or |(D2+ – D2–)| l0.2 V
VCM Common Mode Voltage Range |(D1+ + D1–)|/2 or |(D2+ + D2–)|/2 l0.8 2.5 V
Logic Input Levels (ON, SPNDPWR)
VIHL Logic Input High Voltage l2.0 V
VILL Logic Input Low Voltage l0.8 V
IINL Logic Input Current l±1 µA
VHYSL Logic Input Hysteresis 200 mV
USB Output Levels (D1+, D1–, D2+, D2–)
VOL Output Low Voltage RPU = 1.5k to 3.6V, Figure 4 l0 0.3 V
VOH Output High Voltage RPD = 15k to 0V, Figure 4 l2.8 3.6 V
VCRS Differential Output Signal Cross-Point Voltage l1.3 2.0 V
Terminations
RPU Bus Pull-Up Resistance on Upstream Facing Port D2+ or D2– Pull-Up to 3.3V 1.425 1.575 kΩ
RPD Bus Pull-Down Resistance on Downstream Facing Port D2+ and D2– Pull-Down to GND2 14.25 15.75 kΩ
ZDRV USB Driver Output Resistance l28 44 Ω
CINUSB USB Transceiver Pad Capacitance to GND (Note 2) 10 pF
LTM2884
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swiTching characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VBUS = 5V, GND = GND2 = 0V, ON = VLO, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Low Speed USB
tLDR Low Speed Data Rate CL = 50pF to 450pF (Note 4) 1.5 Mbps
tLR Rise Time Figure 2, CL = 50pF to 600pF l75 300 ns
tLF Fall Time Figure 2, CL = 50pF to 600pF l75 300 ns
tLPRR, tLPFF Propagation Delay Figure 2, CL = 50pF to 600pF l200 300 ns
tLDJ1 Differential Jitter To Next Transition (Note 2) ±45 ns
tLDJ2 Differential Jitter To Paired Transitions (Note 2) ± 15 ns
Full Speed USB
tFDR Full Speed Data Rate CL = 50pF (Note 4) 12 Mbps
tFR Rise Time Figure 3, CL = 50pF l4 20 ns
tFF Fall Time Figure 3, CL = 50pF l4 20 ns
tFPRR, tFPFF Propagation Delay Figure 3, CL = 50pF l60 80 115 ns
tFDJ1 Differential Jitter To Next Transition (Note 2) 2 ns
tFDJ2 Differential Jitter To Paired Transitions (Note 2) 1 ns
Power Supply Generator
VCC2 – GND2 Supply Start-Up Time
(ON VLO, VCC2 to 4.5V)
RLOAD = 50Ω, CLOAD = 100µF
RLOAD = 10Ω, CLOAD = 100µF, VCC = 12V
l
l
2
3
5
10
ms
ms
tWUSPND Wake Up from Suspend Mode Resume Signal, SPNDPWR = 0 l0.25 10 µs
ESD (HBM) (Note 2) Isolation Barrier GND to GND2 ±15 kV
D1+, D1–, D2+, D2–D1+/D1– to GND, VCC, VBUS, or VLO and
D2+/D2– to GND2, VCC2, or VLO2
±15 kV
ON, SPNDPWR ±3 kV
isolaTion characTerisTics
TA = 25°C.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Isolation Barrier: GND to GND2
VISO Rated Dielectric Insulation Voltage
(Notes 6, 7)
1 Minute (Derived from 1 Second Test) 2500 VRMS
1 Second (Note 5) 3000 VRMS
Common Mode Transient Immunity VBUS = VCC = 5V, ON = 3.3V, 1000V in 33ns
Transient Between GND and GND2 (Note 2)
±30 kV/µs
VIORM Maximum Working Insulation Voltage (Notes 2, 5) 560
400
VPEAK
VRMS
Partial Discharge VPR = 750VRMS (Note 5) <5 pC
CTI Comparative Tracking Index IEC 60112 (Note 2) 600 VRMS
Depth of Erosion IEC 60112 (Note 2) 0.017 mm
DTI Distance Through Insulation (Note 2) 0.1 mm
Input to Output Resistance (Notes 2, 5) 1012 Ω
Input to Output Capacitance (Notes 2, 5) 13 pF
Creepage Distance (Notes 2, 5) 9.48 mm
LTM2884
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Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Guaranteed by design and not production tested.
Note 3: This µModule transceiver includes over temperature protection
that is intended to protect the device during momentary overload
conditions. Junction temperature will exceed 125°C when over
temperature protection is active. Continuous operation above specified
maximum operating junction temperature may result in device degradation
or failure.
Note 4: Maximum data rate is guaranteed by other measured parameters
and is not directly tested.
Note 5: Device considered a 2-terminal device. Measurement between
groups of pins A1 through B11 shorted together and pins K1 through L11
shorted together.
Note 6: The rated dielectric insulation voltage should not be interpreted as
a continuous voltage rating.
Note 7: In accordance with UL1577, each device is proof tested for the
2500VRMS rating by applying the equivalent positive and negative peak
voltage multiplied by an acceleration factor of 1.2 for one second.
elecTrical characTerisTics
LTM2884
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Typical perForMance characTerisTics
Low Speed Differential Jitter
VCC2 Output Current
vs Temperature
VCC to VCC2 Efficiency and Power
Loss
VCC Input Current
vs VCC2 Output Current
VCC2 Output Voltage
vs Load Current
Full Speed Propagation Delay
vs Temperature
Low Speed Propagation Delay
vs Temperature Full Speed Differential Jitter
TA = 25°C, VCC = 5V, VBUS = 5V, GND = GND2 = 0V,
ON = 3.3V, unless otherwise noted.
TEMPERATURE (°C)
–50
PROPAGATION DELAY (ns)
100
95
75
90
85
80
70 500 100
2884 G01
12525–25 75
CLOAD = 120pF
TEMPERATURE (°C)
–50
PROPAGATION DELAY (ns)
250
240
230
220
210
200 500 100
2884 G02
12525–25 75
CLOAD = 120pF
10ns/DIV
1V/DIV
2884 G03
JITTER 1.4nsP-P
D1–
D1+
D2–
D2+
50ns/DIV
1V/DIV
2884 G04
JITTER 7.5nsP-P
D1+
D1–
D2+
D2–
TEMPERATURE (°C)
–50
OUTPUT CURRENT (mA)
800
600
700
500
400
300
200 500 100
2884 G05
12525–25 75
VCC = 12V
VCC = 5V
VCC2 = 4.75V
OUTPUT CURRENT (A)
0
INPUT CURRENT (mA)
450
350
400
300
150
200
100
250
50
00.2 0.6
2884 G07
0.80.4
VCC = 12V
VCC = 5V
LOAD CURRENT (A)
0
VCC2 (V)
5.25
4.75
5.00
4.50
4.25
4.00 0.40.2 0.8
2884 G08
1.00.6
VCC = 5V
VCC = 4.4V
VCC = 8.1V
VCC = 12V
IOUT (A)
0
EFFICIENCY (%)
POWER LOSS (W)
70
50
60
40
30
20
0
1.4
1.2
0.8
1.0
0.6
0.4
0.2
0
0.2 0.6
2884 G06
0.80.4
VCC = 5V
VCC = 5V
VCC = 12V
VCC = 12V
POWER LOSS
EFFICIENCY
Derating for 125°C Maximum
Internal Operating Temperature
TEMPERATURE (°C)
25
LOAD CURRENT (A)
0.55
0.45
0.50
0.40
0.25
0.15
0.20
0.35
0.30
0.10
0.05
04535 55 7565 9585 115
2884 G09
125105
VBUS – VCC = 5V
VBUS – VCC = 8.6V
VBUS – VCC = 12V
VBUS – VCC = 16.5V
LTM2884
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Typical perForMance characTerisTics
VCC2 = Load Step Response,
0mA to 500mA (VCC = 12V)
VCC2 = Load Step Response,
0mA to 200mA (VCC = 5V) ICC vs Temperature
Upstream VBUS Droop During
Plug-In with CLOAD = 100µF Full Speed Data Start of Packet
VCC2 Ripple, VCC = 5V,
ICC2 = 200mA VCC2 Start-Up Ramp
TA = 25°C, VCC = 5V, VBUS = 5V, GND = GND2 = 0V,
ON = 3.3V, unless otherwise noted.
2µs/DIV
100mV/DIV
2884 G10
VCC2 Ripple, VCC = 12V,
ICC2 = 500mA
100µs/DIV
500mV/DIV
200mA/DIV
2884 G13
VCC2
ICC2
100µs/DIV
500mV/DIV
200mA/DIV
2884 G14
VCC2
ICC2
TEMPERATURE (°C)
–50
SUPPLY CURRENT (mA)
70
30
60
20
50
40
10
0–25 25 50 75 100
2884 G15
1250
VCC = 12.5V
VCC = 16.5V
VCC = 5V
VCC = 8.1V
VCC = 4.4V
ICC2 = 0mA
500µs/DIV
1V/DIV
2884 G16
ISOLATED VCC2
HOST VBUS
PLUG IN TO HOST
100ns/DIV
500mV/DIV
2884 G17
D2+
D2–
2µs/DIV
100mV/DIV
2884 G11 500µs/DIV
1V/DIV
2884 G12
ON
VCC2
VCC2 Droop/Plug-In Response
200µs/DIV
1V/DIV
2884 G16
VCC
VCC2
LTM2884
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pin FuncTions
Upstream Side (VCC, VBUS, VLO, GND)
D1– (A1): USB Data Bus Upstream Facing Negative
Transceiver Pin. A 1.5k pull-up resistor is automatically
configured to indicate the idle condition of the D2– pin.
D1+ (A2): USB Data Bus Upstream Facing Positive
Transceiver Pin. A 1.5k pull-up resistor is automatically
configured to indicate the idle condition of the D2+ pin.
SPNDPWR (A3): Suspend Power Control. A high input
enables the DC/DC converter shutdown control if the USB
bus is suspended. A low input (GND) disables the shut-
down control to the DC/DC converter maintaining power
to the isolated downstream side during suspend mode.
The recovery time from suspend mode may be equivalent
to the power supply start-up time if the DC/DC converter
was shut down. The SPNDPWR pin is referenced to VLO
and GND.
ON (A4): Enable for Power and Data Communication
Through the Isolation Barrier. If ON is high, the part is
enabled. If ON is low, the upstream side is held in reset
and the isolated side is unpowered by the DC/DC converter.
The ON pin is referenced between VLO and GND.
VLO (A5): Internally Regulated 3.3V Logic Voltage Output.
The VLO pin is used as a positive reference for the ON and
SPNDPWR pins and can source up to 10mA of surplus
current. Internally bypassed to GND with 2.2µF. Output
supply, no external connection necessary.
GND (A6, B1-B11): Upstream Circuit Ground.
VBUS (A7): Voltage Supply Input to USB Transceiver. The
operating range is 4.4V to 16.5V. Connect to the USB
VBUS supply or an external source. Internally bypassed
to GND with 2.2µF.
VCC (A8-A11): Voltage Supply Input to DC/DC Converter.
The operating range is 4.4V to 16.5V. Connect to an external
supply greater than 8.6V for 500mA on VCC2,VBUS must be
connected to the external supply or USB power. Connect
to the USB VBUS for up to 200mA on VCC2. Connect VCC
to VBUS when the peripheral device has an external power
source. Internally bypassed to GND with 4.7µF.
Isolated Downstream Side (VCC2, VLO2, GND2)
GND2 (K1-K11, L3, L4, L6, L7): Downstream Circuit
Ground.
D2– (L1): USB Data Bus Downstream Facing Negative
Transceiver Pin. The pin has a 15k pull-down resistor to
GND2.
D2+ (L2): USB Data Bus Downstream Facing Positive Trans-
ceiver Pin. The pin has a 15k pull-down resistor to GND2.
VLO2 (L5): Internally Regulated 3.3V Logic Voltage Output.
The VLO2 pin can source up to 10mA of surplus current.
Internally bypassed to GND2 with 2.2µF. Output supply,
no external connection necessary.
VCC2 (L8-L11): Isolated Voltage Supply Output from DC/
DC Converter. Output voltage is 5V and can support up to
500mA of peripheral device current referenced to GND2.
Output current is dependant on input supply voltage and
current limit. Internally bypassed to GND2 with 22µF.
Output supply, no external connection necessary.
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block DiagraM
2884 BD
22µF
D2+
VLO2
VCC2
15k
GND2GND
= UPSTREAM SIDE COMMON = DOWNSTREAM SIDE COMMON
15k
DOWNSTREAM
PORT
D2–
4.7µF
VCC
2.2µF
3.3V
REG
3.3V
REG
ISOLATED COMMUNICATION
INTERFACE
ISOLATED COMMUNICATION
INTERFACE
2.2µF
VBUS
VLO
ON
D1+
D1–
2.2µF
DC/DC
SPNDPWR
UPSTREAM
PORT
1.5k 1.5k
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2884 F02
0V
3.3V
0V
3.3V
D1+ OR D2+D2+ OR D1+
CL
D1– OR D2–D2– OR D1–
3.6V
CL
1.5k
tLR
tLPRR tLPFF
tLF
10% 10%
90% 90%
D2+ OR D1+
D2– OR D1–
D1+ OR D2+
D1– OR D2–
2884 F03
0V
3.3V
0V
3.3V
D1+ OR D2+D2+ OR D1+
CL
D1– OR D2–D2– OR D1–
CLtFF
tFPFF tFPRR
tFR
10% 10%
90% 90%
D2– OR D1–
D2+ OR D1+
D1– OR D2–
D1+ OR D2+
Figure 2. Low Speed Timing Measurements
Figure 3. Full Speed Timing Measurements
TesT circuiTs
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FuncTional Table
USB Transceiver Functional Table
MODE D1+D1–AUTOMATIC PULL-UP
CONNECTION D2+D2–SPNDPWR
Full Speed (Idle) 1.5k Pull-Up Host Pull-Down D1+Peripheral Pull-Up 15k Pull-Down X
Low Speed (Idle) Host Pull-Down 1.5k Pull-Up D1–15k Pull-Down Peripheral Pull-Up X
Disconnected (Idle) Host Pull-Down Host Pull-Down None 15k Pull-Down 15k Pull-Down X
Suspend (Idle >3ms) Set at Device Connect Set at Device Connect Set at Device Connect Peripheral or 15k Peripheral or 15k 0
Suspend No Power
(Idle >3ms)
Set at Device Connect Set at Device Connect Set at Device Connect 15k Pull-Down 15k Pull-Down 3.3V
D1 to D2 Data IN+IN–Set at Device Connect OUT+OUT–X
D2 to D1 Data OUT+OUT–Set at Device Connect IN+IN–X
Power Functional Table
MODE ON SPNDPWR VCC VBUS DC/DC CONVERTER
Off 0 X X X OFF
On 3.3V X >4.4V >4.4V ON
On, Suspend (Idle >3ms) 3.3V 0 >4.4V >4.4V ON
On, Suspend (Idle >3ms), Power Off 3.3V 3.3V >4.4V >4.4V OFF
On, USB Transceiver Only Power Off 3.3V X 0 >4.4V OFF
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The LTM2884 µModule transceiver provides a galvanically
isolated robust USB interface, powered by an integrated,
regulated DC/DC converter, complete with decoupling
capacitors. This flexible device can support a variety of
USB configurations, either bus powered or externally
powered. Applications include isolation in hosts, hubs,
peripherals, or standalone inline bus splitters. Automati-
cally configured pull-up resistors are included to represent
the condition of the isolated downstream USB bus to the
upstream USB bus. The LTM2884 is ideal for use in USB
connections where grounds between upstream hub/host
and downstream devices can take on different voltages.
Isolation in the LTM2884 blocks high voltage differences
and eliminates ground loops and is extremely tolerant of
common mode transients between ground potentials. Error
free operation is maintained through common mode events
exceeding 30kV/µs providing excellent noise isolation.
The LTM2884 contains a fully integrated DC/DC converter
including the transformer, so that no external components
are necessary in many configurations. The upstream side
contains a flyback converter that regulates the downstream
output voltage through primary sensing techniques. The
internal power solution is sufficient to support the trans-
ceiver interface and supply up to 500mA at 5V through
VCC2 to an attached device dependent on the supply voltage
and available current on VCC.
The integrated USB transceivers on both sides of the iso-
lation barrier support full and low speed modes defined in
the USB 2.0 specification. The communication through the
isolation barrier for USB is bidirectional and as such the
LTM2884 determines data flow direction based on which
side a start of packet (SOP) begins first. The direction of
data is maintained until an end of packet (EOP) pattern
is observed or a timeout occurs due to a lack of activity.
The USB interface maintains a consistent propagation
delay representative of a hub delay and transfers all data.
Pull-up resistors integrated in the upstream interface
automatically indicate device connections and discon-
nections. A downstream device connection automatically
selects the proper pull-up resistor at the upstream facing
port after sensing the idle state of the downstream device
at connection time. Disconnection of a downstream device
automatically releases the pull-up resistor on the upstream
facing port allowing the upstream 15k pull-down resistors
to pull the bus signals to a disconnect condition. This func-
tion makes the LTM2884 ideal for host, hub, bus splitter,
or peripheral device integration.
Isolator µModule Technology
The LTM2884 utilizes isolator µModule technology to
translate signals and power across an isolation barrier.
Signals on either side of the barrier are encoded into
pulses and translated across the isolation boundary us-
ing differential signaling through coreless transformers
formed in the µModule substrate. This system, complete
with data refresh, error checking, safe shutdown on fail,
and extremely high common mode immunity, provides
a robust solution for bidirectional signal isolation. The
µModule technology provides the means to combine the
isolated signaling with a USB transceiver and powerful
isolated DC/DC converter in one small package.
USB Transceiver Pin Protection
The LTM2884 USB transceiver pins D1+, D1–, D2+, and
D2– have protection from ESD and short-circuit faults.
The transceiver pins withstand ±15KV HBM ESD events.
Overcurrent circuitry on the transceiver pins monitor fault
conditions from D1+ and D1– to GND, VLO, or VBUS and from
D2+ and D2– to GND2, VLO2, or VCC2. A current detection
circuit disables the transceiver pin if the pin sinks about
40mA for greater than 600ns. The VLO and VLO2 output
supplies protect the USB transceiver pins from shorts
to GND or GND2 respectively with a 40mA current limit.
operaTion
LTM2884
14
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For more information www.linear.com/LTM2884
USB Connectivity
The LTM2884 µModule transceiver connects directly to
USB ports on the upstream side and the downstream side
without the addition of external components. The trans-
ceiver passes through all data and does not act as a hub
or intelligent device. The bus lines are monitored for idle
conditions, start of packet, and end of packet conditions
to properly maintain bus speed and data direction. The
series resistance, pull-up, and pull-down resistors are
built into the LTM2884. The upstream facing USB port
contains automatically configured 1.5k pull-up resistors
which are switched in or out based on the downstream
side peripheral device configuration. This implementation
allows upstream reporting of the downstream bus speed
and connection/disconnection conditions. Built-in 15k pull-
down resistors are included from the D2+ and D2– signals
to GND2 supporting the downstream bus configuration.
Monitoring the USB data pins, the LTM2884 detects a
K-state to begin a data packet and set the data direction.
The data is monitored for an end of packet signature and a
finishing J-state before the bus is released. The data pay-
load between the K-state and J-state is transferred through
the LTM2884 isolator with a delay of approximately 80ns.
Idle State Communication and Automatic Speed
Selection
The LTM2884 µModule transceiver maintains the condi-
tions of the USB bus idle state by monitoring the down-
stream side bus idle condition and refreshing the state
across the isolation barrier at a consistent rate. Further-
more, the LTM2884 monitors the speed of the downstream
peripheral once connected and sets its own operation to
match. Figure 4 shows the abbreviated circuitry of the
automatic monitoring and reporting of the bus speeds.
The D2+ or D2– signals are monitored for a connection to
pull-ups on D2+ or D2– and the result is processed as full
speed or low speed, otherwise disconnect. The idle state
is communicated to the upstream side through a refresh
transmission. The switches SW1 or SW2 are controlled
based on the received information. SW1 is closed if D2+
is detected to have a pull-up and D2– was open. SW2 is
closed if D2– is detected to have a pull-up and D2+ was
open. Both SW1 and SW2 are opened if the downstream
USB bus is disconnected. During a USB suspend, the pull-
up resistor will maintain the condition prior to detecting
the suspend command.
applicaTions inForMaTion
Figure 4. Idle State Automatic Resistor Setting
2884 F04
ISOLATION BARRIER
LTM2884
REFRESH
VLO
D1+
RPU
1.5k
RPU
1.5k
SW1 SW2
D1–
15k15k
D2+
D2–
RPD
15k
RPD
15k
1.5k
FULL
SPEED
UPSTREAM CONNECTION DOWNSTREAM CONNECTION
OR
OR DISCONNECTED
LOW
SPEED
1.5k
3.3V 3.3V
LTM2884
15
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For more information www.linear.com/LTM2884
applicaTions inForMaTion
Suspend Mode
When the upstream USB bus is idle for greater than 3ms,
the LTM2884 enters suspend mode. The power savings
and behavior in suspend mode depend on the state of the
SPNDPWR pin, as summarized in Table 1.
Table 1. Suspend Mode Operation
SPNDPWR VCC2 IBUS ICC WAKE-UP
WAKE-UP
TIME
High Off < 500µA VCC/45k Resume 3ms
Low On 1.5mA 50mA Resume or
Remote Wake-Up
10µs
The biggest power savings in suspend mode comes when
SPNDPWR is high. In this case, the DC/DC converter is
disabled, shutting down power to the isolated side, while
the current draw on VCC and VBUS are minimized. How-
ever, in this mode, if a downstream device is connected or
disconnected from the bus or remote wake-up functionality
is configured, it will not be recognized by the LTM2884
and will not be relayed to the host. A resume command
at the upstream side will wake up the LTM2884 and a re-
numeration by the host will be required. Recovery time
is about 3ms from the start of the resume command on
the upstream side.
If SPNDPWR is low in suspend mode, the LTM2884 oper-
ates in a low power mode but maintains a higher functional
state with the DC/DC converter on and the downstream
transceiver powered. The VBUS current is reduced to
1.5mA and VCC current is about 50mA when there is no
external draw on VCC2. Wake-up is initiated with discon-
nects, reconnects, or a remote wake-up command from a
downstream device or a resume command from the host.
Recovery time from suspend mode is about 10µs from
when the first state change is detected.
During suspend mode DC current drawn from VLO into
external circuits will be supplied from VBUS and may exceed
the limits set in the USB specification.
DC/DC Power Supply
The internal DC/DC converter converts the input power
from the VCC pin to the VCC2 output. The power delivered
to the VCC2 pin is regulated and current limited to protect
against overcurrent conditions. The voltage supply, VCC,
is sensed to limit the maximum current that can be delivered
before USB specifications are exceeded. Connecting the VCC
and VBUS supply pins to the USB VBUS pin (4.4V to 5.5V) lim-
its the maximum downstream side supply current to 200mA
before VCC2 supply degradation. When VCC is connected to
a high voltage external DC source (8.6V to 16.5V) the cur-
rent limit is increased so that 500mA is sourced from VCC2.
If a downstream device sinking current from VCC2 draws
more than 25mA, the input current on VCC may exceed
100mA, the USB single unit load specification for low
power devices. The LTM2884 does not enforce a 100mA
current limit for low power peripherals.
VCC2 is internally decoupled to GND2 with a 22µF capaci-
tor. Add an additional low ESR 100µF capacitor to VCC2 to
meet the VBUS downstream supply decoupling minimum
specification of 120µF when supporting device plug in.
Locate the additional 100µF capacitor adjacent to the
downstream USB connector. Additional capacitance may
not be necessary when the LTM2884 is used in a peripheral
device, or upstream hub application.
VLO and VLO2 Supplies
The VLO and VLO2 output supply pins are available for use
as low current 3.3V supplies on both sides of the isolation
barrier. They also serve as supplies for the USB interface
circuitry. An internal linear regulator maintains 3.3V on
VLO from the VBUS input supply. A separate linear regulator
maintains 3.3V on VLO2 from VCC2. The current is limited
to 10mA for external applications. Exceeding this limit
may cause degradation in the VLO or VLO2 supplies and
undesirable operation from the USB isolator. Connection of
signals ON or SPNDPWR to VLO will not cause a significant
change in the available VLO current. These supplies are
available to support interface logic to the isolated USB port.
In order to meet the suspend mode current limit, minimize
the DC current of external applications on the VLO output
supply. VLO and VLO2 are protected from overcurrent and
overtemperature conditions.
LTM2884
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For more information www.linear.com/LTM2884
applicaTions inForMaTion
Supply Current
Loading the multiple output supply pins of the LTM2884
affects the supply current on VBUS and VCC. The VBUS input
supplies current to the the upstream side of the trans-
ceiver and to the VLO pin. The VCC input supplies power
to VCC2 and VLO2 through an isolated DC/DC converter.
The efficiency (η) of the DC/DC converter is shown in the
Typical Performance Characteristics section for 5V and
12V inputs from VCC to VCC2.
Supply Current Equations
Operating:
I
BUS
= 6mA + I
VLO
ICC =VCC2 •6mA + ICC2+ IVLO2
( )
η
•V
CC
Suspend: SPNDPWR = 0
I
BUS
= 1.5mA + I
VLO
ICC =VCC2 •6mA + ICC2 + IVLO2
( )
η•V
CC
Suspend: SPNDPWR = VLO
I
BUS
= 0.45mA + I
VLO
ICC =VCC
45k
Off:
I
BUS =
10µA
ICC = VCC
45k
USB 2.0 Compatibility
The LTM2884 µModule transceiver is compatible with the
USB 2.0 specification of full and low speed operation. Some
characteristics and implementations may not support full
compliance with the USB 2.0 specification. Three specific
cases exist within the LTM2884 µModule transceiver and
the integrated DC/DC power converter.
First, the propagation delay for full speed data of 80ns
exceeds the specification for a single hub of 44ns plus
the attached cable delay of 26ns. This is due to driving
the signal to the 3.3V rail prior to a K-state transition to
maintain balanced crossover voltages equivalent to the
cross over voltages of the successive data transitions.
USB ports commonly drive the idle state bus to the 3.3V
rail prior to the k-state start of packet transition.
Second, setting SPNDPWR = VLO will cause the DC/DC
power converter to turn off during a bus suspend. VCC2
will lose power causing the downstream device to lose
enumeration. Remote wake-up, disconnect, and recon-
nect events are ignored. A resume command from the
host or upstream hub will start the DC/DC converter and
wake up the downstream device. The downstream device
will require re-enumeration, which causes a failure in USB
compliance testing. After a resume command initiates,
a delay of 3ms will elapse before the isolated device is
fully powered. When SPNDPWR = 0V, the DC/DC power
converter remains on during suspend, therefore power
and enumeration information is retained. The VCC supply
consumes 50mA to support the isolated power during
suspend. Separate the VBUS and VCC supplies to comply
with the 2.5mA USB 2.0 VBUS suspend current specification.
Third, when connecting a low power device to the
downstream side of the LTM2884 and VBUS and VCC
are connected together, the input current is higher due
to the operating current and the efficiency of the DC/DC
converter. The operating current of the DC/DC converter
and the USB transceiver function is 46mA. The efficiency
of the converter is approximately 55%, resulting in a 1/0.55
increase in the input current due to the load current on
VCC2. A 100mA load on VCC2 appears as a 181mA load
+ operating current at VBUS and VCC. In order to meet a
100mA input current, the VCC2 load current must be less
than 25mA. This characteristic of an isolated supply may
limit the use of the LTM2884 in bus powered hub applica-
tions or downstream connection to a bus powered hub.
Connect VCC to an external supply to mitigate this concern.
LTM2884
17
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For more information www.linear.com/LTM2884
applicaTions inForMaTion
Hot Plug Protection
The VCC and VBUS inputs are bypassed with low ESR
ceramic capacitors. During a hot plug event, the supply
inputs can overshoot the supplied voltage due to cable
inductance. When using external power supply sources
greater than 10V that can be hot plugged, add an ad-
ditional 2.2µF tantalum capacitor with greater than 1Ω
of ESR, or a ceramic capacitor with a series 1Ω resistor
to the VCC input to reduce the possibility of exceeding
absolute maximum ratings. Refer to Application Note 88,
“Ceramic Capacitors Can Cause Overvoltage Transients,”
for a detailed discussion of this problem.
PC Board Layout
The high integration of the LTM2884 makes PCB layout
simple. However, to optimize its electrical isolation char-
acteristics, EMI, and thermal performance, some layout
considerations are necessary. The PCB layout in Figure 5
is a recommended configuration for a low EMI USB
application. The following considerations optimize the
performance of the LTM2884:
• Under loaded conditions, VCC and GND current exceed
700mA, VCC2 and GND2 current is up to 500mA. Use
sufficient copper on the PCB to ensure resistive losses
do not cause the supply voltage to drop below the
minimum allowed level. The heavy copper traces will
also help to reduce thermal stress and improve thermal
conductivity.
• Input and output decoupling is not required on peripheral
or hub inputs. Add additional low ESR capacitance to
reduce noise induction on the power supply connec-
tions. Hub/bus splitter outputs require an additional
100µF of low ESR capacitance.
• Do not place copper between the inner columns of
pads on the top or bottom of the PCB. This area must
remain open to withstand the rated isolation voltage
and maintain the creepage distance.
RF, Magnetic Field Immunity
The isolator µModule technology used within the LTM2884
has been independently evaluated, and successfully passed
the RF and magnetic field immunity testing requirements
per European Standard EN 55024, in accordance with the
following test standards:
EN 61000-4-3 Radiated, Radio-Frequency,
Electromagnetic Field Immunity
EN 61000-4-8 Power Frequency Magnetic
Field Immunity
EN 61000-4-9 Pulsed Magnetic Field Immunity
Tests were performed using an unshielded test card de-
signed per the data sheet PCB layout recommendations.
Specific limits per test are detailed in Table 2.
Table 2. Test Frequency Field Strength
EN 61000-4-3, Annex D, 80MHz to 1GHz
1.4MHz to 2GHz
2GHz to 2.7GHz
10V/m
3V/m
1V/m
EN 61000-4-8, Level 4 50Hz and 60Hz 30A/m
EN 61000-4-8, Level 5 60Hz 100A/m*
EN 61000-4-9, Level 5 Pulse 1000A/m
*Non IEC Method
EMI
Radiated emissions have been measured for the LTM2884
using a gigahertz transverse electromagnetic (GTEM) cell
with and without a USB cable attached. The performance
shown in Figure 6 was achieved with the layout structure
in Figure 5. Results are corrected per IEC 61000-4-20.
LTM2884
18
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For more information www.linear.com/LTM2884
applicaTions inForMaTion
Figure 5. PC Board Layout
Figure 6. EMI Plot
FREQUENCY (MHz)
0
dBµV/m
60
50
–20
40
30
20
10
–10
–30 400200 600
2884 F06
1000300100 500 700 900800
0
CISPR 22 CLASS B LIMIT
DETECTOR = PEAK-HOLD
RBW = 120kHz
VBW= 300kHz
SWEEP TIME = 680ms
# OF POINTS = 501
2884 F04
TECHNOLOGY
DC1789a Demo Board
DC1789a Top DC1789a Bottom
LTM2884
19
2884fb
For more information www.linear.com/LTM2884
Typical applicaTions
Figure 7. Bus Powered Inline Bus Splitter
Figure 8. USB Hub Upstream Isolator
2884 F08
VLO
ON
SPNDPWR
UPSTREAM TO
USB HOST
VCC2
5V
VBUS
VBUS
GND
VCC
ISOLATION BARRIER
LTM2884
D1+
D1–
VLO2
D2+
D2–
GND2GND
PWR USB HUB
CONTROLLER
DA+
DA–
DB+
DB–
DC+
DC–
4 USB
DOWNSTREAM
PORTS
DD+
DD–
GND2
D+
D–
2884 F07
VLO
ON
SPNDPWR
VCC2 VBUS2
VBUS
VBUS
100mA
OR 500mA
GND
VCC
ISOLATION BARRIER
LTM2884
5V
25mA
OR
200mA
100µF
ISOLATED
DOWNSTREAM
USB PORT
D1+
UPSTREAM
USB PORT
D1–
D+
D–
VLO2
D2+
D2–
D+
D–
GND2
GND2GND
PWR
LTM2884
20
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For more information www.linear.com/LTM2884
Typical applicaTions
Figure 9. USB Host Integration
Figure 10. Powered Peripheral Device with USB Isolation and Low Current Suspend
2884 F09
VLO
ON
SPNDPWR
VCC2 VBUS2
VBUS
GND
VCC
4.4V TO 16.5V
ISOLATION BARRIER
USB HOST
CONTROLLER
LTM2884
5V UP TO
200mA FOR VCC 4.4V TO 5.5V
500mA FOR VCC 8.6V TO 16.5V
100µF
D1+
D1–
15k
VLO2
D2+
D2–
D+
DOWNSTREAM
USB PORT
D–
GND2 GND2
PWR
15k
2884 F10
VLO
ON
SPNDPWR
VCC2
VBUS
VBUS
GND
VCC
ISOLATION BARRIER
LTM2884
D1+
D1–
D+
UPSTREAM
USB PORT
D–
VLO2
D2+
D2–
GND2GND
PWR
PERIPHERAL
5V
LTM2884
21
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For more information www.linear.com/LTM2884
Typical applicaTions
Figure 11. Bus or Self Powered USB Isolation with Low Current Suspend and Power Plug Detection
2884 F11
VLO
ON
SPNDPWR
VCC2
VBUS
GND
VCC
ISOLATION BARRIER
LTM2884
D1+
D1–
D+
UPSTREAM
USB PORT
D–
VLO2
D2+
D2–
GND2GND
PWR
PERIPHERAL
200mA FOR VCC 4.4V TO 5.5V
500mA FOR VCC 8.6V TO 16.5V
VIN
GND
CTL
SENSE
GATE
STAT
LTC4412
VIN
SHDN
UV
OV
4.75k
4.99k
150k
GATE
VOUT
FAULT
GND
LTC4365
OVERVOLTAGE = 16.7V
UNDERVOLTAGE = 8.1V
9V TO 16V (500mA) Si4230DY-TI-GE3
SiA921EDJ
VPLUG
VBUS
Figure 12. Isolated 1W or 2.5W Power Supply
2884 F12
VLO
ON
SPNDPWR
VCC2
VBUS
VPLUG
GND
VCC
ISOLATION BARRIER
LTM2884
D1+
D1–
VLO2
D2+
D2–
GND2GND
PWR
200mA FOR VCC 4.4V TO 5.5V
500mA FOR VCC 8.6V TO 16.5V
4.4V TO 16.5V (500mA)
OFFON
5V
LTM2884
22
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For more information www.linear.com/LTM2884
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
BGA Package
44-Lead (15mm × 15mm × 5.02mm)
(Reference LTC DWG # 05-08-1881 Rev A)
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
2. ALL DIMENSIONS ARE IN MILLIMETERS
BALL DESIGNATION PER JESD MS-028 AND JEP95
4
3
DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
PACKAGE TOP VIEW
4
PIN “A1”
CORNER
X
Y
aaa Z
aaa Z
PACKAGE BOTTOM VIEW
3
SEE NOTES
SUGGESTED PCB LAYOUT
TOP VIEW
DETAIL A
PIN 1
0.000
1.270
2.540
2.540
3.810
1.270
0.3175
0.3175
3.810
5.080
6.350
5.080
6.350
6.350
6.350
5.080
5.080
0.000
DETAIL A
Øb (44 PLACES)
F
G
H
L
J
K
E
A
B
C
D
2 14 356711 8910
DETAIL B
SUBSTRATE
0.37 – 0.47
3.95 – 4.05
// bbb Z
D
A
A1
b1
ccc Z
DETAIL B
PACKAGE SIDE VIEW
MOLD
CAP
Z
MX YZddd
MZeee
0.630 ±0.025 Ø 44x
SYMBOL
A
A1
A2
b
b1
D
E
e
F
G
aaa
bbb
ccc
ddd
eee
MIN
4.82
0.50
4.32
0.71
0.60
NOM
5.02
0.60
4.42
0.78
0.63
15.0
15.0
1.27
12.70
12.70
MAX
5.22
0.70
4.52
0.85
0.66
0.15
0.10
0.20
0.30
0.15
NOTES
DIMENSIONS
TOTAL NUMBER OF BALLS: 44
E
b
e
e
b
A2
F
G
BGA 44 1212 REV A
TRAY PIN 1
BEVEL PACKAGE IN TRAY LOADING ORIENTATION
COMPONENT
PIN “A1”
µModule
LTMXXXXXX
5. PRIMARY DATUM -Z- IS SEATING PLANE
6. SOLDER BALL COMPOSITION CAN BE 96.5% Sn/3.0% Ag/0.5% Cu
OR Sn Pb EUTECTIC
7 PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
LAYOUT CAREFULLY
!
7
SEE NOTES
package DescripTion
Please refer to http://www.linear.com/product/LTM2884#packaging for the most recent package drawings.
LTM2884
24
2884fb
For more information www.linear.com/LTM2884
LINEAR TECHNOLOGY CORPORATION 2014
LT 1116 REV B • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTM2884
relaTeD parTs
Typical applicaTion
PART NUMBER DESCRIPTION COMMENTS
LTM2881 Complete Isolated RS485/RS422 µModule Transceiver + Power 2500VRMS Isolation in Surface Mount BGA or LGA
LTM2882 Dual Isolated RS232 µModule Transceiver with Integrated DC/DC Converter 2500VRMS Isolation in Surface Mount BGA or LGA
LTM2883 SPI or I2C µModule Isolator with Adjustable ±12.5V and 5V Regulated Power 2500VRMS Isolation in Surface Mount BGA
LTM2892 SPI/Digital or I2C µModule Isolator 3500VRMS Isolation, 6 Channels
LTM2894 USB µModule Isolator 7500VRMS Isolation
Figure 13. Self Powered 4-Port Hub with Independent Isolation
2884 F13
VBUS
12V
VLO
VCC
ON
SPNDPWR
GND
ISOLATION BARRIER
LTM2884
D4D–
D4D+
D3C–
D3C+
VLO2
VCC2 VBUSA
GND2
D2+
D2–
DA+
DA–
PWR
USB PORT A
100µF
VBUS
12V
VLO
D2+
D2–
VCC
ON
SPNDPWR
GND
ISOLATION BARRIER
LTM2884
VLO2
VCC2 VBUSB
GND2
DB+
DB–
PWR
USB PORT B
100µF
VBUS
12V
VLO
VCC
ON
SPNDPWR
GND
ISOLATION BARRIER
LTM2884
VLO2
VCC2 VBUSC
GND2
DC+
DC–
PWR
USB PORT C
100µF
VBUS
12V
VLO
VCC
0.2Ω
51k
1.5k
91k
4.7µF
4.7µF
0.2Ω
ON
15k
27Ω
27Ω
SN74LVC04
SPNDPWR
GND
ISOLATION BARRIER
LTM2884
D1–
D1+
D1–
D1+
D2B–
D2B+
D1–
D1+
D1A–
PWRON_A
PWRON_B
PWRON_C
PWRON_D
D1A+
D1–
D1+
VLO2
VCC2 VBUSD
GNDD
GNDC
GNDB
GNDA
GND2
DD+
DD–
PWR
USB PORT D
100µF
STATUS
EN
SD
IN
VS
DS
GATE
GND
LTC1154
12V
27Ω
27Ω
3.3V
3.3V
47k
3.3V
15k
15k
27Ω
27Ω
STATUS
EN
SD
IN
VS
DS
GATE
GND
LTC1154
6MHz CLOCK
SIGNAL
SYSTEM
POWER-ON
RESET
12V
15k
0.2Ω
15k
27Ω
27Ω
STATUS
EN
SD
IN
VS
DS
GATE
GND
LTC1154
12V
15k
0.2Ω
15k
27Ω
27Ω
STATUS
EN
SD
IN
VS
DS
GATE
GND
LTC1154
12V
15k
OVRCUR4
PWRON4
DP4
DM4DP0
DM0
DP0
VBUS
DM0
OVRCUR3
EXTMEM
VCC
12V
GND
PWRON3
DP3
DM3
XTAL1
XTAL2
OVRCUR2
RESET
BUSPWR
EEDATA/
GANGED
GND
PWRON2
DP2
DM2
OVRCUR1
PWRON1
DP1
DM1
SN75240
MAX4594 SPST
GND
NO
COM
IN
V+
3.3V LDO
LT1762-3.3
A
B
C
D
TUSB2046B
3.3V
51k
3.3V
51k
3.3V
51k
3.3V
D2+
D2–
D2+
D2–
