Data Sheet
ADuM4165/ADuM4166
5.7 kV RMS Digital Isolators for Isolated USB 2.0 High, Full, and Low Speed
FEATURES
►
►
►
►
►
►
►
►
►
►
FUNCTIONAL BLOCK DIAGRAMS
USB 2.0 signaling with automatic detection of low, full, and high
speed connections
► 1.5 Mbps, 12 Mbps, and 480 Mbps data rates
Bidirectional USB isolator for upstream or downstream ports
► Redriving and high speed data retiming for input jitter removal
and an open eye
► Flexible clock input options
4.5 V to 5.5 V VBUSx or 3 V to 3.6 V operation on each side
► 21 mA typical idle, low or full speed mode supply current
► 48 mA typical idle, high speed mode supply current
Ultra low power standby in USB 2.0 suspend (L2) or disconnect
► 1.7 mA typical low power standby, upstream supply current
► 20 μA typical low power standby, downstream supply current
±8000 V IEC 61000-4-2 ESD protection across the isolation
barrier
Passed CISPR32/EN55032 Class B emissions
High common-mode transient immunity: 50 kV/μs typical
Safety and regulatory approvals (pending)
► UL (pending): 5700 V rms for 1 minute per UL 1577
► CSA Component Acceptance Notice 5A (pending)
► IEC 62368-1, IEC 61010-1 and IEC60601-1
► VDE certificate of conformity (pending)
► DIN V VDE V 0884-11 (VDE V 0884-11):2017-01
► VIORM = 849 VPEAK
Operating temperature range: −55°C to +125°C
20-lead, wide-body, increased creepage SOIC_IC package with
8.3 mm creepage and clearance
APPLICATIONS
►
►
►
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USB peripheral, USB host, and USB hub isolation
Electronic test and measurement equipment
Medical devices and integrated PCs
Industrial PCs and isolated USB ports for debug or upgrade
USB isolator modules and USB cable isolators
Figure 1. ADuM4165 Clock Input from Host Side
Figure 2. ADuM4166 Clock Input from Peripheral Side
GENERAL DESCRIPTION
The ADuM4165/ADuM41661 are USB 2.0 port isolators, utilizing
®
Analog Devices, Inc., iCoupler technology to dynamically support
all USB 2.0 data rates; low (1.5 Mbps), full (12 Mbps), or high
(480 Mbps), as required. The devices support host isolation with
automatic speed negotiation as well as peripheral isolation.
High speed data is retimed for jitter reduction, requiring an external
clock signal or crystal input. The ADuM4165 supports the clock or
crystal input on the upstream side, and the ADuM4166 supports the
clock or crystal input on the downstream side, offering two options
to best suit the system design.
The low power standby mode for downstream (Side 2) supports
applications with limited available power, such as battery-operated
peripherals. The upstream (Side 1) standby current meets USB 2.0
requirements for suspended operation.
The isolators are specified over an extended industrial temperature
range of −55°C to +125°C and are available in a 20-lead, widebody, increased creepage SOIC_IC with 8.3 mm creepage and
clearance.
1
Protected by U.S. Patents 7,075,329; 8,432,182; 8,525,547; and 8,564,327. Other patents are pending.
Rev. 0
DOCUMENT FEEDBACK
TECHNICAL SUPPORT
Information furnished by Analog Devices is believed to be accurate and reliable "as is". However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to
change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
Data Sheet
ADuM4165/ADuM4166
TABLE OF CONTENTS
Features................................................................ 1
Applications........................................................... 1
Functional Block Diagrams....................................1
General Description...............................................1
Specifications........................................................ 3
Timing Specifications......................................... 5
Insulation and Safety Related Specifications..... 6
Package Characteristics.....................................6
Regulatory Information....................................... 6
DIN V VDE V 0884-11 (VDE V 0884-11)
Insulation Characteristics (Pending).................7
Recommended Operating Conditions................ 8
Absolute Maximum Ratings...................................9
Thermal Resistance........................................... 9
Electrostatic Discharge (ESD) Ratings.............10
ESD Caution.....................................................10
Pin Configurations and Function Descriptions.....11
Truth Tables......................................................12
Typical Performance Characteristics................... 15
Theory of Operation.............................................19
Automatic Data Transfer and Modes................19
Retimer and Other Features.............................19
Isolator Characteristics and Low Power
Modes.............................................................20
Applications Information...................................... 21
Power Supply Options......................................21
Clock Options................................................... 21
PGOOD, Clock, and Power Sequencing..........22
Isolated USB Implementations......................... 22
PCB Layout and Electromagnetic
Interference (EMI).......................................... 24
Insulation Lifetime............................................ 24
Outline Dimensions............................................. 26
Ordering Guide.................................................26
Evaluation Boards............................................ 26
REVISION HISTORY
3/2022—Revision 0: Initial Version
analog.com
Rev. 0 | 2 of 26
Data Sheet
ADuM4165/ADuM4166
SPECIFICATIONS
4.5 V ≤ VBUS1 ≤ 5.5 V, 4.5 V ≤ VBUS2 ≤ 5.5 V, 3.0 V ≤ VDD1 ≤ 3.6 V, and 3.0 V ≤ VDD2 ≤ 3.6 V. All minimum and maximum specifications are
applied over the entire recommended operation range, unless otherwise noted. All typical specifications are at TA = 25°C and VDD1 = VDD2 =
3.3 V, unless otherwise noted. Each voltage is relative to its respective ground.
Table 1.
Parameter
POWER SUPPLY
Supply Current
Idle (VDD1, VDD2, VBUS1 or VBUS2)1
Low or Full Speed Mode
High Speed Mode
Symbol
Min
VDD2 Maximum Voltage Until After
Side 1 Start-Up
Side 1 Start-Up Time
VBUS1 or VBUS2 Undervoltage Lockout
(UVLO)
UVLO Threshold, VBUS1 or VBUS2
Rising
UVLO Threshold, VBUS1 or VBUS2
Falling
VBUS1 or VBUS2 UVLO Hysteresis
VDD1 or VDD2 Undervoltage Lockout
UVLO Threshold, VDD1 or VDD2
Rising
UVLO Threshold, VDD1 or VDD2
Falling
VDD1 or VDD2 UVLO Hysteresis
LOGIC INPUTS
Input Current
UD+ and UD−
DD+ and DD−
XI1 and XI2
Single-Ended Inputs
Input Logic High Threshold
Input Logic Low Threshold
Input Hysteresis
analog.com
Max
Unit
Test Conditions/Comments
21
27
mA
48
60
mA
29
45
mA
Input frequency (fIN) = 750 kHz, load capacitance (CL) = 450 pF
31
45
mA
fIN = 6 MHz, CL = 50 pF
59
70
mA
fIN = 240 MHz, CL = 10 pF
1.7
1.7
20
40
40
2.5
mA
mA
µA
µA
µA
V
USB suspended or disconnected
Side 2 not powered
Side 2 powered (average)
VBUS2 = VDD2 = 3 V to 3.6 V, Side 1 not powered
VBUS2 = 4.5 V to 5.5 V, Side 1 not powered
Side 1 powered (average)
See the PGOOD, Clock, and Power Sequencing section
UD+, UD−, DD+, and DD− idle
IDD1(LFI),
IDD2(LFI)
IDD1(HI),
IDD2(HI)
Busy (VDD1, VDD2, VBUS1, or VBUS2)2
Low Speed Mode
IDD1(L),
IDD2(L)
Full Speed Mode
IDD1(F),
IDD2(F)
High Speed Mode
IDD1(H),
IDD2(H)
Low Power Standby
Upstream (VDD1 or VBUS1)
IDD1(S)
Downstream (VDD2 and VBUS2)
Typ
IDD2(S)
VSTART
40
100
3.5
tSTART
3
ms
VUVLO5+
3.5
4.16
4.35
V
VUVLO5−
3.0
3.77
3.95
V
VUVLO5HST
0.44
V
VUVLO3+
2.4
2.77
2.95
V
VUVLO3−
2.2
2.60
2.90
V
VUVLO3HST
0.18
V
IIN
0 V ≤ input voltage (VIN) ≤ 3.6 V
−20
−250
−30
VIH
VIL
VHYS
Time after VDD1 rises above VUVLO3+3 before VDD2 can be >3.5 V,
see the PGOOD, Clock, and Power Sequencing section
+0.1
+0.1
+0.1
+20
+250
+30
µA
µA
µA
0.8
V
V
V
2.0
0.4
Rev. 0 | 3 of 26
Data Sheet
ADuM4165/ADuM4166
SPECIFICATIONS
Table 1.
Parameter
Symbol
High Speed Input Differential
Threshold4
Low and Full Speed Differential Input
Sensitivity4
OUTPUTS (DRIVERS)
Low or Full Speed Output Voltages
Logic High
Logic Low
Transceiver Capacitance4
VTH
Min
VDI
0.2
VOH
VOL
CIN
0.8 VDDx
0
At Logic Low Output7
ZOUTH
Max
0.09
Capacitance Matching4
Full Speed Driver Impedance
Impedance Matching
COMMON-MODE TRANSIENT
IMMUNITY4
At Logic High Output6
Typ
40.5
3.6
0.3
Unit
Test Conditions/Comments
V
|(DD+) – (DD−)| or |(UD+) – (UD−)|
V
|(DD+) – (DD−)| or |(UD+) – (UD−)|
14
V
V
pF
19
1
3
45
10
pF
%
%
Ω
%
49.5
|CMTIH|
40
50
kV/µs
|CMTIL|
40
50
kV/µs
UD+, UD−, DD+, and DD−
Load resistance (RL) = 15 kΩ, load voltage (VL) = 0 V
RL = 1.5 kΩ, VL = 3.6 V
CIN, UD+ or CIN, UD− (UD+ or UD− to GND1), CIN, DD+ or CIN, DD−
(DD+ or DD− to GND2), fIN = 6 MHz
CIN, UD+, CIN, UD−, CIN, DD+ or CIN, DD−, fIN = 240 MHz
|1 − CIN, UD+/CIN, UD−|
|1− CIN, DD+/CIN, DD−|
UD+ and UD− or DD+ and DD−
Common-mode voltage (VCM) = 1000 V, transient magnitude =
800 V5
VIN = VDD1 for UD+ or UD− (other input = 0 V), VIN = VDD2 for
DD+ or DD− (other input = 0 V)
UD+ and UD− = 0 V, or DD+ and DD− = 0 V
1
Measured when the device is powered, connected to a USB host, and connected to a USB peripheral using the specified communication speed. However, the USB is idle
without being suspended, meaning there has been no USB activity for a frame interval (1 ms for low or full speed, or 0.125 ms for high speed), but short keep alive packets
may be occurring within each frame to keep the USB from suspending.
2
The busy USB supply current values are for the device running at a fixed continuous data rate at 50% duty cycle, alternating J and K states. Supply current values are
specified with a USB-compliant load present.
3
VUVLO3+ is the UVLO threshold, VDD1 or VDD2 rising.
4
These specifications are guaranteed by design and characterization.
5
CMTI is the maximum common-mode voltage slew rate that can be sustained while maintaining specification compliant operation. VCM is the common-mode potential
difference between Side 1 and Side 2. The transient magnitude is the range over which the common mode is slewed. The common-mode voltage slew rates apply to both
rising and falling common-mode voltage edges.
6
Output voltage for UD+ or UD− > 0.8 VDD1 (other output ≤ 0.3 V), and output voltage for DD+ or DD− > 0.8 VDD2 (other output ≤ 0.3 V).
7
UD+ and UD− ≤ 0.3 V or DD+ and DD− ≤ 0.3 V.
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Rev. 0 | 4 of 26
Data Sheet
ADuM4165/ADuM4166
SPECIFICATIONS
TIMING SPECIFICATIONS
4.5 V ≤ VBUS1 ≤ 5.5 V, 4.5 V ≤ VBUS2 ≤ 5.5 V, 3.0 V ≤ VDD1 ≤ 3.6 V, and 3.0 V ≤ VDD2 ≤ 3.6 V. All minimum and maximum specifications were
applied over the entire recommended operation range, unless otherwise noted. All typical specifications are at TA = 25°C and VDD1 = VDD2 =
3.3 V, unless otherwise noted. Each voltage is relative to its respective ground.
Table 2.
Parameter
USB INPUT AND OUTPUT PINS LOW
SPEED MODE
Data Rate
Propagation Delay2
Output Rise and Fall Time (10% to 90%)
Differential Jitter
Next Transition
Paired J to K Transition
Paired K to J Transition
USB INPUT AND OUTPUT PINS FULL
SPEED MODE
Data Rate
Propagation Delay2
Output Rise/Fall Time (10% to 90%)
Differential Jitter
Next Transition
Paired J to K Transition
Paired K to J Transition
USB INPUT AND OUTPUT PINS HIGH
SPEED MODE
Data Rate
Propagation Delay3
Output Rise and Fall Time (10% to 90%)
Differential Jitter (rms)
Next Transition
Paired J to K Transition
Paired K to J Transition
Differential Jitter (peak)
Next Transition
Paired J to K Transition
Paired K to J Transition
Symbol
Min
Typ
Max1
Unit
Test Conditions/Comments
UD+, UD−, DD+, and DD− and CL = 450 pF
tPHLL, tPLHL
tRL/tFL
300
300
75
75
|tLJN|
|tLJPJK|
|tLJPKJ|
1.5
500
500
600
650
300
350
5
2
3
Mbps
ns
ns
ns
ns
TA = 25°C and VDD1 = VDD2 = 3.3 V
TA = 25°C and VDD1 = VDD2 = 3.3 V
ns
ns
ns
UD+, UD−, DD+, and DD−, and CL = 50 pF
tPHLF, tPLHF 70
tRF/tFF
4
4
|tFJN|
|tFJPJK|
|tFJPKJ|
12
110
140
20
32
450
300
500
Mbps
ns
ns
ns
TA = 25°C and VDD1 = VDD2 = 3.3 V
ps
ps
ps
UD+, UD−, DD+, and DD−, and CL = 10 pF
tPHLH, tPLHH 71
tRH, tFH
675
480
73
77
Mbps
ns
ps
|tHJN(R)|
|tHJPJK(R)|
|tHJPKJ(R)|
40
11
14
ps rms
ps rms
ps rms
|tHJN(P)|
|tHJPJK(P)|
|tHJPKJ(P)|
90
30
40
ps
ps
ps
1
These specifications are guaranteed by design and characterization.
2
Propagation delay of the low or full speed USB signals in either direction is measured from the 50% level of the input signal rising or falling edge to the 50% level of the
rising or falling edge of the corresponding output signal. This delay is between one and two hub differential data delays as defined in USB 2.0 specification, Table 7-11
(THDD1 and TLHDD parameters).
3
Propagation delay of the high speed USB signals in either direction is measured from the 50% level of the input signal rising or falling edge to the 50% level of the rising
or falling edge of the corresponding output signal. This delay is specified to be less than one hub data delay (without cable) as defined in USB 2.0 specification, Table 7-11
(THSHDD parameter).
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Rev. 0 | 5 of 26
Data Sheet
ADuM4165/ADuM4166
SPECIFICATIONS
INSULATION AND SAFETY RELATED SPECIFICATIONS
For additional information, see www.analog.com/icouplersafety.
Table 3.
Parameter
Symbol
Value
Unit
Test Conditions/Comments
Rated Dielectric Insulation Voltage
Minimum External Air Gap (Clearance)
L (I01)
5.7
8.3
kV rms
mm min
Minimum External Tracking (Creepage)
L (I02)
8.3
mm min
Minimum Clearance in the Plane of the Printed Circuit Board
(PCB Clearance)
Minimum Internal Gap (Internal Clearance)
Tracking Resistance (Comparative Tracking Index)
Material Group
L (PCB)
8.1
mm min
CTI
25.5
>600
I
µm min
V
1 minute duration
Measured from input terminals to output terminals, shortest distance
through air
Measured from input terminals to output terminals, shortest distance
path along body
Measured from input terminals to output terminals, shortest distance
through air, line of sight, in the PCB mounting plane
Insulation distance through insulation
Tested in accordance to IEC 60112
Material Group per IEC 60664-1
PACKAGE CHARACTERISTICS
Table 4.
Parameter
Symbol
Resistance (Input to Output)1
RI-O
CI-O
Capacitance (Input to Output)1
1
Min
Typ
1012
2.2
Max
Unit
Test Conditions/Comments
Ω
pF
Voltage (input to output) (VI-O) = 500 V dc
Frequency = 1 MHz
Device is considered a 2-terminal device; Pin 1 through Pin 10 are shorted together, and Pin 11 through Pin 20 are shorted together.
REGULATORY INFORMATION
See Table 10 for details regarding the recommended maximum working voltages for specific cross-isolation waveforms and insulation levels.
Table 5.
Regulatory Agency
Standard Certification/Approval
File
UL (Pending)
To be recognized under UL 1577 Component Recognition Program1
E214100
CSA (Pending)2
VDE (Pending)
CQC (Pending)
Single protection, 5700 V rms isolation voltage
To be approved under CSA Component Acceptance Notice 5A
CSA 62368-1-19, EN 62368-1:2020 and IEC 62368-1:2018 third edition
Basic insulation at 830 V rms
Reinforced insulation at 415 V rms
CSA 61010-1-12+A1 and IEC 61010-1 third edition
Basic insulation at 600 V rms
Reinforced insulation at 300 V rms
CSA 60601-1:14 and IEC60601-1 third edition, A1
To be certified according to DIN V VDE V 0884-11 (VDE V 0884-11):2017-013
Reinforced insulation, VIORM = 849 VPEAK, VIOSM = 10000 VPEAK
To be certified according to GB4943.1-2011 per CQC11-471543-2015
Basic insulation at 820 V rms (1159 VPEAK)
Reinforced insulation at 410 V rms (578 VPEAK)
205078
2471900-4880-0001
Pending
1
In accordance with UL 1577, each ADuM4165/ADuM4166 is proof tested by applying an insulation test voltage ≥6840 V rms for 1 sec.
2
Working voltages are quoted for Pollution Degree 2, Material Group III. ADuM4165/ADuM4166 case material has been evaluated by CSA as Material Group I.
3
In accordance with DIN V VDE V 0884-11, each ADuM4165/ADuM4166 is proof tested by applying an insulation test voltage ≥1592 VPEAK for 1 sec (partial discharge
detection limit = 5 pC).
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Rev. 0 | 6 of 26
Data Sheet
ADuM4165/ADuM4166
SPECIFICATIONS
DIN V VDE V 0884-11 (VDE V 0884-11) INSULATION CHARACTERISTICS (PENDING)
This isolator is suitable for reinforced electrical isolation only within the safety limit data. Protective circuits ensure the maintenance of the safety
data.
Table 6.
Test Conditions/Comments1
Description
Installation Classification per DIN VDE 0110
For Rated Mains Voltage ≤ 150 V rms
For Rated Mains Voltage ≤ 300 V rms
For Rated Mains Voltage ≤ 600 V rms
Climatic Classification
Pollution Degree per DIN VDE 0110, Table 1
Maximum Working Insulation Voltage
Input to Output Test Voltage, Method B1
VIORM × 1.875 = VPD (M), 100% production test, tINI = tM = 1
sec, partial discharge < 5 pC
Input to Output Test Voltage, Method A
After Environmental Tests Subgroup 1
VIORM × 1.5 = VPD (M), tINI = 60 sec, tM = 10 sec, partial
discharge < 5 pC
After Input or Safety Test Subgroup 2 and Subgroup 3 VIORM × 1.2 = VPD (M), tINI = 60 sec, tM = 10 sec, partial
discharge < 5 pC
Highest Allowable Overvoltage
Surge Isolation Voltage
Reinforced
VPEAK = 16 kV, 1.2 µs rise time, 50 µs, 50% fall time
Safety Limiting Values
Maximum value allowed in the event of a failure (see Figure 3)
Maximum Junction Temperature
Total Power Dissipation at 25°C
Insulation Resistance at TS
VIO = 500 V
1
Symbol
Characteristic
Unit
VIORM
VPD (m)
I to IV
I to IV
I to IV
40/125/21
2
849
1592
VPEAK
VPEAK
1274
VPEAK
1019
VPEAK
VIOTM
8000
VPEAK
VIOSM
10000
VPEAK
TS
PS
RS
150
2.5
>109
°C
W
Ω
VPD (m)
For information about tM, tINI, and VIO, see DIN V VDE V 0884-11.
Figure 3. Thermal Derating Curve, Dependence of Safety Limiting Values with Ambient Temperature per DIN V VDE V 0884-11
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Rev. 0 | 7 of 26
Data Sheet
ADuM4165/ADuM4166
SPECIFICATIONS
RECOMMENDED OPERATING CONDITIONS
Table 7.
Parameter
Symbol
Rating
Operating Temperature
Supply Voltages
TA
VBUS1, VBUS2
VDD1, VDD2
−55°C to +125°C
3.0 V to 5.5 V
3.0 V to 3.6 V
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Rev. 0 | 8 of 26
Data Sheet
ADuM4165/ADuM4166
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 8.
Parameter
Rating
Supply (VBUS1, VDD1) to GND1
Supply (VBUS2, VDD2) to GND2
Upstream Input Voltage (UD−, UD+, XI1, and
XO1) to GND1
Downstream Input Voltage (DD−, DD+, XI2,
XO2, and PGOOD) to GND2
Common-Mode Transients1
Temperature
Operating Range
Storage Range
Junction (TJ Maximum)
Power Dissipation2
−0.5 V to +6.5 V
−0.5 V to +6.5 V
−0.5 V to VDD1 + 0.5 V
−0.5 V to VDD2 + 0.5 V
−100 kV/µs to +100 kV/µs
−55°C to +125°C
−65°C to +150°C
150°C
(TJ maximum − TA)/θJA
1
Refers to common-mode transients across the insulation barrier. Commonmode transients exceeding the absolute maximum ratings may cause latch-up
or permanent damage.
2
See Figure 3 for the maximum power dissipation for various temperatures.
Thermal performance is directly linked to PCB design and operation
environment. Close attention to PCB thermal design is required.
θJA is the natural convection, junction to ambient thermal resistance
measured in a one cubic foot sealed enclosure. ΨJT is the junction
to top thermal characterization parameter.
Table 9. Thermal Resistance
Package Type1
θJA
ΨJT
Unit
RI-20-1
50
2.3
°C/W
1
Test Condition 1: thermal impedance simulated with 4-layer standard JEDEC
PCB.
Stresses at or above those listed under Absolute Maximum Ratings
may cause permanent damage to the product. This is a stress
rating only; functional operation of the product at these or any other
conditions above those indicated in the operational section of this
specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability.
Table 10. Maximum Continuous Working Voltage1
Parameter
Rating
Constraint
AC Voltage
Bipolar Waveform
Basic Insulation
650 V rms
600 V rms
Basic insulation rating per IEC60747-17. Accumulative failure rate over lifetime (FROL) ≤
1000 ppm at 20 years.
Reinforced insulation rating per IEC60747-17. Accumulative FROL ≤ 1 ppm at 26 years.
1838 VPEAK
1355 VPEAK
Rating limited by AC bipolar waveform accumulative FROL ≤ 1000 ppm at 20 years.
Rating limited by package creepage per IEC 60664-1 in Pollution Degree 2 environment.
1660 V dc
830 V dc
Rating limited by package creepage per IEC 60664-1 in Pollution Degree 2 environment.
Rating limited by package creepage per IEC 60664-1 in Pollution Degree 2 environment.
Reinforced Insulation
Unipolar Waveform
Basic Insulation
Reinforced Insulation
DC Voltage
Basic Insulation
Reinforced Insulation
1
Maximum continuous working voltage refers to the continuous voltage magnitude imposed across the isolation barrier in a Pollution Degree 2 environment. See the
Insulation Lifetime section for more details.
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Rev. 0 | 9 of 26
Data Sheet
ADuM4165/ADuM4166
ABSOLUTE MAXIMUM RATINGS
ELECTROSTATIC DISCHARGE (ESD) RATINGS
The following ESD information is provided for handling of ESD-sensitive devices in an ESD protected area only.
Human body model (HBM) per ANSI/ESDA/JEDEC JS-001.
International electrotechnical commission (IEC) electromagnetic
compatibility: Part 4-2 (IEC) per IEC 61000-4-2.
ESD Ratings for ADuM4165/ADuM4166
Table 11. ADuM4165/ADuM4166, 20-Lead SOIC_IC
ESD Model
Withstand Threshold (V)
Class
HBM1
IEC2
±4000
±8000 (contact discharge)
3A
Level 4
1
All pins to respective GNDx, 1.5 kΩ, 100 pF.
2
GND1 to GND2 or GND2 to GND1 across isolation barrier.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although
this product features patented or proprietary protection circuitry,
damage may occur on devices subjected to high energy ESD.
Therefore, proper ESD precautions should be taken to avoid
performance degradation or loss of functionality.
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Rev. 0 | 10 of 26
Data Sheet
ADuM4165/ADuM4166
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 4. ADuM4165 Pin Configuration
Table 12. ADuM4165 Pin Function Descriptions
Pin No.
Mnemonic
Description
1
VBUS1
2, 10
3
GND1
VDD1
4, 7
GND1
5
6
8
9
11, 19
12
13
14
XI1
XO1
UD+
UD−
GND2
DD+
DD−
PGOOD
15, 16, 17
GND2
18
VDD2
20
VBUS2
Optional 5 V Power Supply/Low Dropout (LDO) Input for Side 1. Connect VBUS1 to 4.5 V to 5.5 V and bypass to GND1 using a 0.1 μF
capacitor to power Side 1 from a 5 V supply (an integrated LDO regulator generates the 3.3 V required internally). Alternatively, if powering
Isolator Side 1 directly from an external 3.3 V power supply, connect both VBUS1 and VDD1 together to 3.3 V. (Bypass to GND1 is still
required.)
Ground, Side 1. Ground reference for Isolator Side 1, connect to Side 1 PCB ground.
3.3 V Power Supply/LDO Output for Side 1. Bypass to GND1 with a required capacitor value of 0.1 μF for correct operation of the internal
3.3 V regulator (used when connecting 5 V to VBUS1). Alternatively, if powering Isolator Side 1 directly from an external 3.3 V power supply,
connect both VBUS1 and VDD1 together to 3.3 V. (Bypass to GND1 is still required.)
Ground, Side 1. These pins must be connected to Side 1 PCB ground for proper operation. These pins are not suitable for connection of
bypass capacitance.
Crystal Input or External Clock Input, Isolator Side 1.
Crystal Output Driver, Isolator Side 1.
USB D+ Signal, Upstream (Isolator Side 1).
USB D− Signal, Upstream (Isolator Side 1).
Ground 2. Ground reference for Isolator Side 2, connect to Side 2 PCB ground.
USB D+ Signal, Downstream (Isolator Side 2).
USB D− Signal, Downstream (Isolator Side 2).
Power Good. High output indicates that the voltages at VBUS1/VDD1 and VBUS2/VDD2 are greater than UVLO thresholds, and low output
indicates VBUS1/VDD1 or VBUS2/VDD2 are less than UVLO thresholds. When PGOOD is low, Side 2 reverts to low power standby mode.
Ground 2. These pins must be connected to Side 2 PCB ground for proper operation. These pins are not suitable for connection of bypass
capacitance.
3.3 V Power Supply/LDO Output for Side 2. Bypass to GND2 with a required capacitor value of 0.1 μF for correct operation of the internal
3.3 V regulator (used when connecting 5 V to VBUS2). Alternatively, if powering Isolator Side 2 directly from an external 3.3 V power supply,
connect both VBUS2 and VDD2 together to 3.3 V. (Bypass to GND2 is still required.)
Optional 5 V Power Supply/LDO Input for Side 2. Connect VBUS2 to 4.5 V to 5.5 V and bypass to GND2 using a 0.1 μF capacitor to power
Side 2 from a 5 V supply (an integrated LDO regulator generates the 3.3 V required internally). Alternatively, if powering Isolator Side 2
directly from an external 3.3 V power supply, connect both VBUS2 and VDD2 together to 3.3 V. (Bypass to GND2 is still required.)
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Data Sheet
ADuM4165/ADuM4166
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 5. ADuM4166 Pin Configuration
Table 13. ADuM4166 Pin Function Descriptions
Pin No.
Mnemonic
Description
1
VBUS1
2, 10
3
GND1
VDD1
4, 5, 6, 7
GND1
8
9
11, 19
12
13
14
UD+
UD−
GND2
DD+
DD−
PGOOD
15
16
17
XO2
XI2
GND2
18
VDD2
20
VBUS2
Optional 5 V Power Supply/LDO Input for Side 1. Connect VBUS1 to 4.5 V to 5.5 V and bypass to GND1 using a 0.1 μF capacitor to power
Side 1 from a 5 V supply (an integrated LDO regulator generates the 3.3 V required internally). Alternatively, if powering Isolator Side 1
directly from an external 3.3 V power supply, connect both VBUS1 and VDD1 together to 3.3 V. (Bypass to GND1 is still required.)
Ground, Side 1. Ground reference for Isolator Side 1, connect to Side 1 PCB ground.
3.3 V Power Supply/LDO Output for Side 1. Bypass to GND1 with a required capacitor value of 0.1 μF for correct operation of internal 3.3
V regulator (used when connecting 5 V to VBUS1). Alternatively, if powering Isolator Side 1 directly from an external 3.3 V power supply,
connect both VBUS1 and VDD1 together to 3.3 V. (Bypass to GND1 is still required.)
Ground, Side 1. These pins must be connected to Side 1 PCB ground for proper operation. These pins are not suitable for connection of
bypass capacitance.
USB D+ Signal, Upstream (Isolator Side 1).
USB D− Signal, Upstream (Isolator Side 1).
Ground 2. Ground reference for isolator side 2, connect to side 2 PCB ground.
USB D+ Signal, Downstream (Isolator Side 2).
USB D− Signal, Downstream (Isolator Side 2).
Power Good. High output indicates that the voltages at VBUS1/VDD1 and VBUS2/VDD2 are greater than UVLO thresholds, and low output
indicates VBUS1/VDD1 or VBUS2/VDD2 are less than UVLO thresholds. When PGOOD is low, Side 2 reverts to low power standby mode.
Crystal Output Driver, Isolator Side 2.
Crystal Input or External Clock Input, Isolator Side 2.
Ground 2. This pin must be connected to Side 2 PCB ground for proper operation. This pin is not suitable for connection of bypass
capacitance.
3.3 V Power Supply/LDO Output for Side 2. Bypass to GND2 with a required capacitor value of 0.1 μF for correct operation of internal 3.3
V regulator (used when connecting 5 V to VBUS2). Alternatively, if powering Isolator Side 2 directly from an external 3.3 V power supply,
connect both VBUS2 and VDD2 together to 3.3 V. (Bypass to GND2 is still required).
Optional 5 V Power Supply/LDO Input for Side 2. Connect VBUS2 to 4.5 V to 5.5 V and bypass to GND2 using a 0.1 μF capacitor to power
Side 2 from a 5 V supply (an integrated LDO regulator generates the 3.3 V required internally). Alternatively, if powering Isolator Side 2
directly from an external 3.3 V power supply, connect both VBUS2 and VDD2 together to 3.3 V. (Bypass to GND2 is still required).
TRUTH TABLES
Table 14. USB Signals, All Modes
State
UD+
UD−
DD+
DD−
Downstream Disconnected
No Host or Peripheral
Low (host pull-down)
High-Z
Low (host pull-down)
High-Z
Low (15 kΩ pull-down)
Low (15 kΩ pull-down)
Low (15 kΩ pull-down)
Low (15 kΩ pull-down)
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Data Sheet
ADuM4165/ADuM4166
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Table 15. USB Signals, High Speed
State
UD+
UD−
DD+
DD−
Idle and Reset
Initiate Suspend (3.125 ms)
Upstream Disconnected
J to Downstream
J to Upstream
K to Downstream
K to Upstream
Low1
Low1
Low1
Low (host pull-down)2
Low (host pull-down)2
Low (15 kΩ pull-down)2
High (1.5 kΩ pull-pp)3
High (1.5 kΩ pull-up)
~0.4 V due to host1
~0.4 V per DD+1
Low1
Low1
Low (host pull-down)
High-Z
Low1
Low1
~0.4 V due to Host1
~0.4 V per DD–1
High (peripheral pull-up)3
High (peripheral pull-up) 4
~0.4 V per UD+1
~0.4 V due to peripheral1
Low1
Low1
Low1
Low (15 kΩ pull-down)2
Low (15 kΩ pull-down)
Low (15 kΩ pull-pown)
Low1
Low1
~0.4 V per UD–1
~0.4 V due to peripheral1
1
After high speed handshake, host and peripheral terminate to local GND with 45 Ω. The isolator also terminates UD+, UD–, DD+, and DD– to local GND with its own 45 Ω
resistors. During high speed transmission, the host or peripheral and the isolator drive 17.8 mA on the appropriate D+ or D– signals, giving a voltage of ~0.4 V across the
parallel 45 Ω terminations.
2
UD+ and UD– are pulled down by the host reverting to full speed termination (connecting 15 kΩ to GND). High speed 45 Ω termination remains connected to DD+ and DD–
by the peripheral, and internally by the isolator on UD+ and UD– until the peripheral switches to suspend. Upon entry to suspend, 45 Ω terminations are disconnected, and
1.5 kΩ pull-ups are connected to DD+ (by the peripheral) and UD+ (by the isolator).
3
UD+ also has an external 15 kΩ pull-down connected by the host; a corresponding internal 15 kΩ pull-down is connected by the isolator to DD+. DD+ is high due to
external 1.5 kΩ pull-up connected by the peripheral, corresponding internal 1.5 kΩ pull-up is connected on UD+, setting the UD+ pin state high.
4
A 15 kΩ pull-down is connected on DD+.
Table 16. USB Signals, Full Speed
State
UD+1
UD−
DD+1, 2
DD–2
Idle and Reset
Upstream Disconnected
J to Downstream
J to Upstream
K to Downstream
K to Upstream
SE0 to Downstream
SE0 to Upstream
High (pull-up)
High (pull-up)
High (host)
High (driven per DD+)
Low (host)
Low (driven per DD+)
Low (host)
Low (driven per DD+)
Low (host pull-down)
High-Z
Low (host)
Low (driven per DD–)
High (host)
High (driven per DD–)
Low (host)
Low (driven per DD–)
High (peripheral pull-up)
High (peripheral pull-up)
High (driven per UD+)
High (peripheral)
Low (driven per UD+)
Low (peripheral)
Low (driven per UD+)
Low (peripheral)
Low (pull-pown)
Low (pull-pown)
Low (driven per UD−)
Low (peripheral)
High (driven per UD–)
High (peripheral)
Low (driven per UD–)
Low (peripheral)
1
A 1.5 kΩ pull-up is connected on UD+ by the isolator, per peripheral 1.5 kΩ pull-up on DD+.
2
A 15 kΩ pull-down is connected on DD+ and DD− by the isolator.
Table 17. USB Signals, Low Speed
State
UD+
UD−1
DD+2
DD–1, 2
Idle and Reset
Upstream Disconnected
J to Downstream
J to Upstream
K to Downstream
K to Upstream
SE0 to Downstream
SE0 to Upstream
Low (host pull-down)
High-Z
Low (host)
Low (driven per DD+)
High (host)
High (driven per DD+)
Low (host)
Low (driven per DD+)
High (pull-up)
High (pull-up)
High (host)
High (driven per DD–)
Low (host)
Low (driven per DD–)
Low (host)
Low (driven per DD−)
Low (pull-down)
Low (pull-down)
Low (driven per UD+)
Low (peripheral)
High (driven per UD+)
High (peripheral)
Low (driven per UD+)
Low (peripheral)
High (peripheral pull-up)
High (peripheral pull-up)
High (driven per UD–)
High (peripheral)
Low (driven per UD–)
Low (peripheral)
Low (driven per UD−)
Low (peripheral)
1
A 1.5 kΩ pull-up connected on UD– by the isolator, per peripheral 1.5 kΩ pull-up on DD–.
2
A 15 kΩ pull-down connected on DD+ and DD– by the isolator.
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Data Sheet
ADuM4165/ADuM4166
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Table 18. Control Signals and Power (Positive Logic)
VBUS1 (V)
VDD1 (V)
VBUS2 (V)
VDD2 (V)
PGOOD
UD+/UD–
DD+/DD–
5 or 3.3
0
5 or 3.3
0
3.3
0
3.3
0
5 or 3.3
5 or 3.3
0
0
3.3
3.3
0
0
High
Low
High-Z
High-Z
Per normal operation
High-Z
High-Z (no host) or low (host pull-ups)
High-Z
Per normal operation
Low (15 kΩ pull-down)
High-Z
High-Z
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Data Sheet
ADuM4165/ADuM4166
TYPICAL PERFORMANCE CHARACTERISTICS
VBUS1 = VDD1 = 3.3 V, VBUS2 = VDD2 = 3.3 V, and TA = 25°C unless otherwise noted.
Figure 6. Low Speed Propagation Delay vs. Ambient Temperature, TA
Figure 9. Low Speed Eye Diagram (Downstream Shown)
Figure 7. Full Speed Propagation Delay vs. Ambient Temperature, TA
Figure 10. Full Speed Eye Diagram (Downstream Shown)
Figure 8. High Speed Propagation Delay, tPHLH or tPLHH vs. Ambient
Temperature, TA
Figure 11. High Speed Eye Diagram (Downstream Shown)
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Rev. 0 | 15 of 26
Data Sheet
ADuM4165/ADuM4166
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 12. Low Speed Data (Downstream, DD+ and DD−)
Figure 15. Low Speed Data (Upstream, UD+ and UD−)
Figure 13. Full Speed Data (Downstream, DD+ and DD−)
Figure 16. Full Speed Data (Upstream, UD+ and UD−)
Figure 14. High Speed Data (Downstream)
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Data Sheet
ADuM4165/ADuM4166
TERMINOLOGY
Bus
The universal serial bus (USB) connects up to 127 devices via
the D+ and D− signals in a star type topology with a hierarchy
comprising multiple tiers (up to 6).
Upstream and Downstream
Upstream and downstream refer to the directions of the data flow
on the bus. Upstream means toward the higher tiers of the USB
device hierarchy (closer to the USB host atop the hierarchy), and
downstream means toward the lower tiers of the USB device
hierarchy (farther from the host). ADuM4165/ADuM4166 include
an upstream facing port (UFP) and a downstream facing port
(DFP) to allow insertion into an existing connection between a DFP
(connecting to UD+ and UD–) and a UFP (connecting to DD+ and
DD–).
Hub
A hub is a USB device that provides additional connections to the
USB, including at least one DFP. Typically, a standalone hub has a
UFP that connects to the DFP of another device, and multiple DFPs
of its own to expand the number of devices that can be connected
to the USB. The combination of a single upstream connection to
multiple downstream connections creates a star topology. Each
additional hub connecting its UFP to another DFP of a hub adds a
tier in the USB hierarchy. The ADuM4165/ADuM4166 add between
one and two hub plus cable delays, and accordingly, for a device
integrating the isolator into a UFP or a DFP, two fewer tiers can be
added to the hierarchy for that isolated USB port.
Host
A host is a USB device that includes the USB host controller and a
hub (termed the root hub) containing at least one DFP, for example
a PC or laptop that typically allows connection of a large variety of
other USB devices.
Peripheral
A peripheral is a USB device with a UFP that can communicate
with a USB host. Examples are portable devices offering access
to records (mass storage and data logs), a configuration (debug
port), a data stream (camera and measurements), or inputs (mouse
and keyboard). Portable devices and specific purpose equipment
that rely on a UFP for connection to a PC or a laptop for configuration can also include a separate USB host and associated DFP,
which independently of the UFP, allows connection of a mouse, a
keyboard, mass storage, or daughter modules.
Enumeration
Enumeration is the initial communication when a USB peripheral
connects to the bus and identifies itself to the host, including its
intended USB communication speed.
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Low Speed
Low speed is the operation of USB communication at 1.5 Mbps,
with voltage mode drivers to switch two signals, D+ and D−, to low
and high voltage levels near 0 V and 3.3 V, respectively. During
enumeration, a peripheral requests low speed communication by
connecting a 1.5 kΩ pull-up to D−.
Full Speed
Full speed is the operation of USB communication at 12 Mbps, with
voltage mode drivers for low speed to switch two signals, D+ and
D−, but with shorter rise times, fall times, and unit intervals. During
enumeration, a peripheral requests full speed communication by
connecting a 1.5 kΩ pull-up to D+.
High Speed
High speed is operation of USB communication at 480 Mbps, with
current mode drivers and 45 Ω to ground terminations for the D+
and D− signals, giving low and high voltage levels of approximately
0 V and 0.4 V, respectively.
During enumeration, a high speed capable peripheral initially
presents as full speed (1.5 kΩ connected to D+). However, when
the host resets the USB in preparation for communication, the
peripheral drives current into the D− signal for high speed communication (the K state). Because the host is driving a single-ended
zero into the D+ and D− signals (connecting both via 45 Ω to
ground), this results in a low voltage on the D− signal of ~0.8 V.
This particular chirp K signal is ignored by a full speed host. However, a high speed host can detect the chirp and initiate a handshake
sequence to enter high speed mode with the peripheral, sending
KJ pairs. After at least three KJ pairs, the peripheral completes the
handshake by applying its 45 Ω, high speed termination resistors.
Refer to Automatic Data Transfer and Modes for an example handshake through ADuM4165/ADuM4166, with the isolator ensuring
both the host and the peripheral can negotiate this seamlessly. The
isolator connects its own internal terminations on UD+ and UD−
(45 Ω to GND1) or DD+ and DD− (45 Ω to GND2) at appropriate
times during the handshake sequence to match behavior of host
and peripheral.
End of Packet (EOP)
For low and full speed, EOP is indicated by a SE0 state at the
end of a data packet, before the USB becomes idle (J state). For
high speed, the SE0 state is present during idle conditions due to
the 45 Ω to ground connections already present on the D+ and D–
signals at both ends of the USB connection to provide high speed
termination. Therefore, EOP is instead indicated by transmission of
the Byte 0111 1111, distinguished by a bit stuffing error of >6 bits in
a row with 1.
J State
In the J state, the D+ and D− signals are driven high or low to
match the pull-up resistor applied by the peripheral. Therefore, for
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Data Sheet
ADuM4165/ADuM4166
TERMINOLOGY
low speed, D− is high and D+ is low, whereas for full speed, D+
is high and D− is low. Similarly for high speed (initially pull-up on
D+ per full speed), the J state corresponds to a positive differential
voltage (the voltage on D+ is greater than the voltage on D−, VD+ >
VD−). Refer to the Truth Tables section for additional information.
L1 Suspend
The K state is opposite of the J state. For low speed, D+ is high,
and D− is low, whereas for full speed, D− is high and D+ is low.
Similarly for high speed, the K state corresponds to a negative
differential voltage (VD+ < VD−). Refer to the Truth Tables section for
additional information.
L1 suspend is an additional sleep low power mode defined by
the USB 2.0 link power management engineering change notice
(ECN). This mode allows shorter entries and resume intervals
than the original USB 2.0 suspend, although the maximum power
consumption can be higher. L1 suspend must be entered via a
handshaking packet exchange between the host and an L1 capable
device, which includes negotiation of the L1 entry and exit intervals.
This mode is not supported by all hosts or devices. In addition, L1
suspend is not supported by the ADuM4165/ADuM4166 because
the handshake packets are not detected or interpreted by the
isolator.
SE0 State
L2 Suspend
In the SE0 state, both D+ and D− are driven low (regardless of
any pull-up on D+ or D−). During low and full speed USB signaling,
the SE0 state is used to signal EOP or reset. During high speed
signaling, the SE0 state occurs between data packets and results
from both the host and peripheral having 45 Ω connected from D+
to ground and from D− to ground. These 45 Ω connections provide
differential termination of 90 Ω at both ends of the USB connection.
This mode is the standard suspend mode defined in the base USB
2.0 specification and called L2 suspend in the link power management ECN. This mode offers the lowest power consumption and
is supported by the ADuM4165/ADuM4166. To initiate L2 suspend,
the host stops USB data traffic on a USB segment for at least 3 ms,
and connected devices detect the sustained period of idle bus.
K State
SE1 State
The SE1 state is an illegal bus state where the D+ and D− signals
are both high. If this state is somehow applied to one side of
ADuM4165/ADuM4166, the isolator does not propagate this error
state in either direction.
Idle
In the idle state, no data is transmitted. For low and full speed, the
D+ and D− signals are per the applied pull-up resistor or pulled low
(D− high and D+ low for low speed, and D+ high and D− low for
full speed). For high speed, no differential voltage is transmitted.
However, 45 Ω to ground terminations are still present at D+ and
D−, giving the SE0 state voltage conditions. Refer to the Truth
Tables section for additional information.
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Data Sheet
ADuM4165/ADuM4166
THEORY OF OPERATION
The ADuM4165/ADuM4166 comprise galvanic isolation implement®
ed with Analog Devices, Inc., iCoupler technology enhanced for up
to 480 Mbps operation, combined with USB 2.0 signal retransmission (including retiming). To repeat USB 2.0 signals bidirectionally,
the isolators include both low, full, and high speed USB transmitters and receivers, and integrated phase-locked loops (PLLs) for
retiming and internal synchronization. The isolators also include
control logic to automatically control direction, speed, pull-ups, or
pull-downs or to enter a low power suspend mode with much lower
power consumption than required by the USB 2.0 standard.
AUTOMATIC DATA TRANSFER AND MODES
The ADuM4165/ADuM4166 realize the complex task of seamlessly
isolating the bidirectional USB D+ and D− signals, without requiring
access to external USB controllers or transceivers control signals.
Isolation without interfering with USB communication is achieved
with the control logic in the isolator. This control logic monitors activity on both the upstream and downstream D+ and D− waveforms
and automatically determines what actions to perform, including
the appropriate control of the USB transceivers integrated within
the isolator, without requiring user intervention. The isolator reconstructs the signal on the output while retaining precise timing and
not passing invalid SE1 states.
In addition, the isolator detects enumeration signals that set the
data transfer speed to low, full, or high speed. An example of the
ADuM4165/ADuM4166 allowing negotiation into high speed mode
between the host and the peripheral is shown in Figure 17. After
a low, full, or high speed USB connection is established, activity at
a D+ or D− input sets the direction for the data transfer based on
a transition from the idle state. When data direction is established,
data transfer continues until either an EOP or a sufficiently long idle
state is encountered. At this point, the isolator disables the USB
transmitters on what was the output side and monitors both sets of
D+ and D− inputs for the next activity.
Figure 17. ADuM4166 High Speed Handshake
During data transfers, the input side of the isolator disables its USB
transmitters while keeping its USB receiver active. The output side
enables its USB transmitters and disables edge detection from its
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USB receiver. This automatic control of which side is enabled for
data transmission allows the data to flow in one direction without erroneously feeding back. Logic is included to eliminate any artifacts
due to different input thresholds of the differential and single-ended
USB receivers. Either J, K, or SE0 transfer across the isolation
barrier as one of the three valid states. The isolator output signal is
a delayed copy of the input.
RETIMER AND OTHER FEATURES
In support of high speed mode, the isolator retimes the output data
using an elastic buffer first in, first out (FIFO) that is clocked with
a PLL locked to a precision 24 MHz reference clock applied to XI1
or XI2. This retiming minimizes jitter and skew in the USB output
signal, providing a clean open eye that can potentially have fewer
timing errors than the input signal. The XI1 or XI2 reference clock
input is either an oscillation developed across an external crystal
connected between XI1 and XO1 (or XI2 and XO2), or an external
clock signal applied directly to XI1 or XI2. A copy of the internal PLL
reference clock signal transfers through the isolation barrier. Therefore, only one clock input is required. The two versions offered for
this isolator allow customers to choose where to input the clock:
Side 1 for ADuM4165 or Side 2 for ADuM4166.
The retiming behavior via the elastic buffer is equivalent to that
of a high speed repeater within a USB 2.0 hub, as described in
USB 2.0, Chapter 7.1.14.2. As mentioned in USB 2.0, Chapter
7.1.10, such repeaters are allowed to drop up to 4 bits from the
start of the synchronization field (SYNC) when repeating packets,
where the packets consist of an initial SYNC pattern, followed
by the packet payload and concluding with the EOP sequence.
The isolator accordingly drops up to 4 bits from the start of the
SYNC pattern as it copies the high speed packets from input to
output as part of its elastic buffer function. All subsequent packet
content is passed, including all the remaining SYNC bits, the packet
payload, and the EOP. No bits are corrupted. The propagation delay
conforms to USB 2.0 requirements for high speed repeaters. The
isolator is equivalent to a USB 2.0 high speed repeater, in terms of
data retiming, potential dropped SYNC bits, and propagation delay.
The isolator has a special low power mode to support low power
peripherals. If either side of the isolator is not powered, either the
host or the peripheral are disconnected or the USB is suspended,
low power mode activates. During this mode, some circuits turn off
to minimize power consumption, especially on Side 2 to help extend
battery life in battery-operated devices. If new power connections
are detected or USB activity is detected, low power mode automatically exits. The isolators comply overall with USB 2.0 requirements
for suspend, resume, or remote resume situations, entering or
exiting low power mode as appropriate with glitch-free transitions
at D+/D–, correct resume signaling, and entry to suspend plus
completion of resume within the required timing.
The isolators also provide a PGOOD output on Side 2 to indicate
validity of Side 1 and Side 2 power supply voltages. PGOOD
asserts when both sides have valid power supply voltages above
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Data Sheet
ADuM4165/ADuM4166
THEORY OF OPERATION
UVLO thresholds. PGOOD is no longer asserted if either side has
an invalid supply voltage below UVLO thresholds.
ISOLATOR CHARACTERISTICS AND LOW
POWER MODES
The ADuM4165/ADuM4166 combine enhanced Analog Devices,
iCoupler channels for transmitting at 480 Mbps, high speed data
rates with standard isolator channels for internal communication
and synchronization. Current is steered into the input coils of the
high speed channel, and the direction is switched to generate
transitions on the receiving coil. This current steering technique
minimizes parasitic coupling and emissions, with a trade-off of not
switching off the current between edge transitions. Combining this
technique with a high speed USB transceiver results in a total
power consumption of approximately 50 mA per side during high
speed data transfers, which is the maximum power consumption
case for the isolator.
The USB isolator uses several power management techniques to
reduce power consumption for each operating condition. Often in
USB signaling, the D+ and D− signals only switch a small percentage of the time and are idle much more often. During the idle USB
state, the isolator saves some power by turning off components
that are only needed when there is active USB traffic. The isolator
includes fast reacting and the higher power circuits required for high
speed communications on the USB lines and across the isolation
barrier. These components are turned off to save power when
there is not active high speed communication, significantly reducing
power for full speed or low speed connections, as well as high
speed suspend mode.
Side 1 is 1.7 mA, and the average typical supply currents for
Side 2 are 20 μA or 40 μA.
Note that during suspended USB conditions, low power mode is
active, and Side 1 (upstream) average power consumption is less
than the 2.5 mA USB 2.0 requirement for the suspend current.
Side 2 (downstream) average power consumption is even smaller,
typically 20 μA or 40 μA. Enough circuits on Side 1 are kept awake
to help resume active communications quickly, while
Side 2 implements more aggressive power control to minimize
power drawn from the peripheral. This behavior facilitates use of
the isolators in battery-operated peripherals, where the peripherals
may need to operate efficiently for long periods of idle time between
bursts of communications.
Note that many USB systems send a keep alive signal to peripherals even when no data is required to keep the peripherals from
going into a suspend state. Review the drivers when very low
power is required so that the suspend state is allowed to occur.
These design features help minimize average power consumption
from the isolators.
If D+ and D− are idle for more than 3 ms, USB connections
enter suspend mode. The isolator monitors for the suspended USB
conditions, or if no peripheral is connected to Side 2 for more
than 3 ms. When either is detected, the ADuM4165/ADuM4166
enter their low power mode and their internal control logic switches
off many circuits to drastically reduce power consumption. The
isolators automatically detect resume signals or new connections in
order to exit low power mode at the appropriate times and to enable
new USB communication.
These techniques working together give the following power consumption cases:
1. Approximately 48 mA or 59 mA per side for idle or busy high
speed USB connections, respectively.
2. Approximately 21 mA or 30 mA per side for idle or busy,
respectively, during full speed or low speed connections.
3. 1.7 mA for Side 1 and 20 μA or 40 μA for Side 2 during the
low power mode, which is active when the USB is suspended or
disconnected. When Side 1 is not powered, Side 2 enters low
power mode with a supply current maximum of 40 μA (VBUS =
VDD2 = 3 V to 3.6 V) or 100 μA (VBUS2 = 4.5 V to 5.5 V). When
both sides are powered, the average typical supply current for
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Rev. 0 | 20 of 26
Data Sheet
ADuM4165/ADuM4166
APPLICATIONS INFORMATION
The ADuM4165/ADuM4166 flexibly support three main implementations for isolating USB devices:
start-up sequencing when using the LDO regulator, while 0.1 μF can be
used, if desired, without affecting isolator start-up sequencing.
The ADuM4165/ADuM4166 are transparent to USB traffic. No modifications to the peripheral design or isolator specific drivers are
required to provide isolation, except for a requirement that while
L2 suspend is implemented, L1 suspend (sleep) must not be implemented because it is not supported by the ADuM4165/ADuM4166.
Another consideration is that the isolators add a propagation delay
to the USB signals of between one and two hub plus cable delays.
Isolated peripherals integrating the ADuM4165/ADuM4166 must
be treated as if these devices contain two built-in hubs when
determining the maximum number of hubs and/or tiers permitted in
the end installation.
External pull-up resistors are not required because these resistors
are integrated within the isolator to mirror the connection status of
any USB devices attached to the downstream side of the isolator.
Apart from electromagnetic compatibility (EMC) protection to meet
system requirements, such as TVS diodes for ESD, the only external components required are decoupling capacitors and potentially
a crystal (if a 24 MHz clock is not available from a microcontroller).
The main design choices include using the ADuM4165 or the
ADuM4166, implementing the required 24 MHz clock, and choosing
the power supply option.
POWER SUPPLY OPTIONS
Power must be supplied separately to both sides of the
ADuM4165/ADuM4166, using either 3.3 V or 5 V supplies. All
combinations are supported across the full extended operating
temperature range, whether using the same supply voltage on both
sides, or 3.3 V on one side and 5 V on the other (either way
for either the ADuM4165 or the ADuM4166). An example of the
ADuM4166 with the required connections for the 5 V supply on
Side 1 and the 3.3 V supply on Side 2 is shown in Figure 21.
External 5 V supplies (including from the USB cable) can be directly
connected to the isolator via the VBUS1 pin (to power Side 1) or the
VBUS2 pin (to power Side 2). In this configuration, the relevant VBUS1
or VBUS2 pin powers an internal LDO regulator on that side of the
isolator. Either LDO regulator when connected in this configuration
provides a 3.3 V output at the relevant VDD1 or VDD2 pin, which
is used to power the internal circuits in the isolator including its
USB transceivers. Do not use the output of either regulator to
power external devices. The VDD1 and VDD2 pins require a bypass
capacitor externally with a value of 0.1 μF (>0.1 μF can disrupt
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When Side 2 is in low power mode (due to USB suspend or
disconnected conditions, or the supply voltage of Side 1 is less
than the UVLO thresholds), circuits within the isolator connect the
VDD2 pin to the VBUS2 pin, and the VDD2 LDO regulator is then
disabled to save power and achieve very low supply currents. If the
LDO regulator was previously active (that is, VBUS2 connected to
5 V), VDD2 rises from 3.3 V to 5 V during low power mode. Upon
exiting low power mode, the VDD2 LDO regulator is reenabled, and
the VDD2 voltage returns to 3.3 V. By contrast, if the Side 2 LDO
regulator was already inactive (VBUS2 = VDD2 = 3.3 V), the VDD2
voltage does not change from a nominal 3.3 V during entry to or
exit from low power mode.
CLOCK OPTIONS
An external 24 MHz clock source is required by the ADuM4165/ADuM4166 to support high speed data recovery and retiming. USB
2.0 requires retiming of high speed data passing through repeaters,
to prevent jitter from accumulating if data packets pass through a
series of devices. The isolator performs the high speed retiming
function with the aid of a precision clock input. For maximum
flexibility and robustness, there are two options for implementation
of the clock. A crystal can be connected between XI1 and XO1 for
the ADuM4165 or XI2 and XO2 for the ADuM4166, or if a precision
24 MHz clock is available from the microprocessor, that signal can
be connected to the XI1 or XI2 pin, and XO1 or XO2 can be left
open.
The crystal choice and implementation are critical to proper functioning of the circuit. To meet ADuM4165/ADuM4166 specifications,
a frequency tolerance of ≤50 ppm with ≤100 ppm stability is
required. When using the isolator across the full extended temperature range, ensure that the system is built using a crystal meeting these requirements across the desired operating temperature
range.
To comply with USB 2.0 requirements for suspend and resume,
the crystal oscillator must start up within 0.3 ms as the isolator
powers on initially or exits low power mode. To achieve this requirement, follow the PCB guidelines shown in Figure 21, together
with a typical crystal capacitance of 10 pF and capacitive loads