1. Measured between pins 1, 3, 4, 6 and ground with pin 5 also grounded.
2. For other resistance values (e.g. 15
W,
33
W),
please contact your local ON Semiconductor sales representative.
TYPICAL CHARACTERISTICS
0
−5
−10
(dB)
−15
−20
−25
−30
0.10
Temp = 25°C
1.00
10.00
FREQUENCY (MHz)
100.00
1000.00
Figure 1. Insertion Loss Characteristics
24.5
R
S
= Typical
24.0
23.5
R
S
(W)
23.0
22.5
22.0
21.5
−20
1600
1580
1560
R
UP
(W)
1540
1520
1500
1480
−10
0
10
20
30
40
50
60
70
1460
−20 −10
0
10
20
30
40
50
60
70
R
UP
= Typical
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 2. R
S
versus Temperature
Figure 3. R
UP
versus Temperature
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2
NUF2221W1
APPLICATIONS BACKGROUND
What is USB?
The USB is not a serial port, it is a serial bus, a fact that
enables a single port on the computer to be a link for a myriad
of devices, (up to 127 devices in a USB system). We can
easily chain one device to another and use one port as a
connecting point of many devices by using a hub. All these
enable us to look at the USB system as a small network of
devices.
The Universal Serial Bus (USB) makes connecting
devices to your computer faster, easier and virtually
limitless. High−Speed USB devices are capable of
communicating at speeds up to 12 megabytes−without
shutting down and without having to open your computer.
Typical USB System
Monitor
Scanner
HUB
Printer
KeyBoard
Mouse
Computer PC
CPU
Telephone
devices, handling the power management for devices that
are bus−powered (get power from the bus), and
responsibility for bus error detection and recovery. Another
important role of the hub is to manage both full and low
speed devices. When a device is attached to the system the
hub detects the speed, which the device operates in, and
through the whole communication on the bus prevents from
full speed traffic to reach low seed device and vice versa
– prevent from low speed traffic to reach full speed device.
The Device
Plotter
The Device is defined as everything in the USB system,
which is not a host (including hubs). A device provides one
or more USB functions. Most of the devices provide only
one function but there may be some, which provides more
than one and called compound devices. We refer to two
kinds of devices
−
self powered or bus powered devices. A
device that gets its power from the bus is called bus powered
and on the other hand a device which supplies its own power
is called self powered. There are two kinds of devices for
USB 1.1:
Full−speed devices
−
operates in 12 Mb/s
Low−speed devices that work in 1.5 Mb/s.
NUF2221W1 Device Information
Figure 4. Typical USB System
Typically the USB system consists of one host, hubs and
devices.
The Host
The host in the USB system, is responsible to the whole
complexity of the protocol (simplifies the designing of USB
devices). The host controls the media access, therefore, no
one can access the bus unless it got an approval required
from the host.
The Hub
The hub provides an interconnect point, which enables
many devices to connect to a single USB port. The logical
topology of the USB is a star structure, all the devices are
connected (logically) directly to the host. It is totally
transparent to the device what is its’ hub tier (the number of
hubs the data has to flow through). The hub is connected to
the USB host in the upstream direction (data flows ”up” to
the host) and is connected to the USB device in the
downstream direction (data flows ”down” from the host to
the device). The hubs’ main functionality is the
responsibility of detecting an attachment and detachment of
The Universal Serial Bus (USB) specification revision 1.1
requires the USB drivers to have certain impedance
characteristics. The series resistance plus the USB driver
output resistance must be close to the USB cable’s
impedance of 45
W
unbalanced (90
W
balance) to minimize
transmission line reflections. In addition USB 1.1 also
requires upstream ports to be terminated with a pull−up
resistor (usually 1.5 kW) from D+ or D− lines to V
CC
=3.3 V
(V
CC
is usually taken from V
BUS
by using a 5 V
−
3.3 V
regulator). In case of EMI, the radiated and conducted EMI
should be kept within the required levels as specified by the
FCC regulations. Actual FCC regulations requires that class
B computing devices meet the specifications of maximum
levels for both radiated and conducted EMI (Radiated EMI
covers the frequency range from 30 MHz to 1 GHz and
Conducted EMI covers the 450 kHz to 30MHz range).
The NUF2221W1 device from On Semiconductor
provides series termination, EMI filtering and ESD
protection for the two data lines (D+, D−) as well as for the
VBUS. The ESD device’s ratings comply with
IEC61000−4−2 (Level 4), HBM class 3B and MM class C.
All these features are offered in an integrated solution placed
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3
NUF2221W1
in a small and single package (SC−88, Case 419B). The
NUF2221W1 device is shown in the Figure 5.
D
1(C)
6
V
BUS
5
D
2(C)
4
USB
CONTROLLER
D+
1
R
S
R
UP
C
1
C
1
3
R
S
4
D−
6
3.3 V
5
D+
USB
CONNECTOR
D−
3.3 V
5
USB
CONNECTOR
D+
terminal 6. Finally, the input of the D− line is connected in
the terminal 3 which outputs from the terminal 4. Figure 6
shows the connections of the NUF2221W1 device for
“Full−Speed”.
R
UP
R
S
C
1
C
1
R
S
0
D−
2
Figure 6. Full Speed Connection
1
D
1(i)
2
GND
3
D
2(i)
Low−Speed Connection
Figure 5. Device Description
Connection for Full− Speed and Low−Speed Devices
The USB 1.1 specification calls for two data rates:
•
Full−speed devices
−
operates in 12 Mb/s
•
Low−speed devices that work in 1.5 Mb/s.
The NUF2221W1 device can be shaped for either full−speed
or low−speed by connecting one of the data lines (D+, D−)
to a 3.3 V voltage supply through the 1.5 kW pull up resistor.
The device’s connection diagrams for each speed are
described as follows:
Full−Speed Connection
The Pull up resistor (R
UP
) is connected to the D− Line.
The terminal 5 is connected to a 3.3 V voltage supply while
the terminal 2 is connected to ground. The input of the D−
line is connected in the terminal 1 which outputs from the
terminal 6. Finally, the input of the D+ line is connected in
the terminal 3 which outputs from the terminal 4. The
Figure 7 shows the connections of the NUF2221W1 device
for “Low−Speed”.
D−
USB
CONTROLLER
1
R
S
R
UP
C
1
C
1
3
R
S
4
6
0
D+
2
The Pull up resistor (R
UP
) is connected to the D+ Line.
The terminal 5 is connected to a 3.3 V voltage supply while
the terminal 2 is connected to ground. The input of the D+
line is connected in the terminal 1 which outputs from the
Figure 7. Low Speed Connection
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4
NUF2221W1
PACKAGE DIMENSIONS
SC−88/SC70−6/SOT−363
CASE 419B−02
ISSUE W
D
e
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. 419B−01 OBSOLETE, NEW STANDARD 419B−02.
DIM
A
A1
A3
b
C
D
E
e
L
H
E
MILLIMETERS
MIN
NOM MAX
0.80
0.95
1.10
0.00
0.05
0.10
0.20 REF
0.10
0.21
0.30
0.10
0.14
0.25
1.80
2.00
2.20
1.15
1.25
1.35
0.65 BSC
0.10
0.20
0.30
2.00
2.10
2.20
INCHES
NOM MAX
0.037 0.043
0.002 0.004
0.008 REF
0.004 0.008 0.012
0.004 0.005 0.010
0.070 0.078 0.086
0.045 0.049 0.053
0.026 BSC
0.004 0.008 0.012
0.078 0.082 0.086
MIN
0.031
0.000
6
5
4
H
E
1
2
3
−E−
b
6 PL
0.2 (0.008)
M
E
M
A3
C
A
SOLDERING FOOTPRINT*
0.50
0.0197
A1
L
0.65
0.025
0.65
0.025
0.40
0.0157
1.9
0.0748
SCALE 20:1
mm
inches
SC−88/SC70−6/SOT−363
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor
and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone:
303−675−2175 or 800−344−3860 Toll Free USA/Canada
Fax:
303−675−2176 or 800−344−3867 Toll Free USA/Canada
Email:
orderlit@onsemi.com
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800−282−9855 Toll Free
USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
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Phone: 81−3−5773−3850
ON Semiconductor Website: www.onsemi.com
Order Literature:
http://www.onsemi.com/orderlit
For additional information, please contact your local
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