USB375x
USB 2.0 Protection IC with
Battery Charger Detection
PRODUCT FEATURES
Datasheet
VBUS Over-Voltage Protection
— Protects internal circuits from VBUS up to 9V
— Over-Voltage/Under-Voltage Lockout opens VBUS
switch
— Interrupt to indicate Over-Voltage/Under-Voltage
Lockout
— Integrated Low RDSON FET
High Speed USB Mux for multiplexing the USB lanes
between different functions (USB3750 only)
Provides USB Battery Charger Detection for:
— USB-IF Battery Charging compliant Dedicated Charging
Ports (DCP)
— USB-IF Battery Charging compliant Charging
Downstream Port (CDP)
SMSC RapidCharge Anywhere™ Provides:
— 3-times the charging current through a USB port over
traditional solutions
— USB-IF Battery Charging 1.2 compliance to any
portable device
— Charging current up to 1.5Amps via compatible USB
host or dedicated charger
— Dedicated Charging Port (DCP), Charging (CDP) &
Standard (SDP) Downstream Port support
— Switch the USB connector between two different
functions
— High bandwidth USB switch passes HS USB signals
Dead Battery Provision Support (USB375x-1 only)
— Allows 100mA trickle charging from VBUS when
attached to a Standard Downstream Port (SDP) while
not enumerated
— Built-in 100mA current limiting option
USB Port ESD Protection (DP/DM/VBUS)
— ±15kV (air discharge)
— ±15kV (contact discharge)
— IEC 61000-4-2 level 4 ESD protection without external
devices
— Standard Downstream Port (SDP); i.e. USB host or
downstream hub port
— Dedicated SE1 type chargers
flexPWR® Technology
— Extremely low current design ideal for battery powered
applications
— Maximizes power delivered to the system
Industrial Operating Temperature -40°C to +85°C
USB375x Block Diagram
HS Switch is USB3750 feature only
VBUS
DM_2
DP
DM
VBUS
GND
ESD Protection
USB Connector
DP_2
HS USB
Switch
DP_1
DM_1
DP
DM
DP
DM
VBUS
Over-Voltage/Under-Voltage
Protection and Current
Limiting
Charger
Detection
I2C
Interface
SMSC USB375x
VOUT
SCL
SDA
INT_B
VBUS
USB 2.0 PHY,
Processor, or
Accessory
USB 2.0 PHY,
Processor, or
Accessory
Battery
Charger/
PMU
Processor
Revision 1.1 (02-12-13)
DATASHEET
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Order Numbers:
ORDER NUMBER
PACKAGE TYPE
PACKAGE SIZE
16 pin, QFN lead-free RoHS compliant
package
3.0mm x 3.0mm
USB3750A-1-A4-TR
(see Note 1)
USB3751A-1-A4-TR
(see Note 2)
USB3751A-2-A4-TR
(see Note 3)
Note 1
Provides HS mux and support for 100mA dead battery current limiting.
Note 2
Provides support for 100mA dead battery current limiting.
Note 3
Does not provide support for 100mA dead battery current limiting.
This product meets the halogen maximum concentration values per IEC61249-2-21
For RoHS compliance and environmental information, please visit www.smsc.com/rohs
Please contact your SMSC sales representative for additional documentation related to this product
such as application notes, anomaly sheets, and design guidelines.
Copyright © 2013 SMSC or its subsidiaries. All rights reserved.
Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete information sufficient for
construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC
reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications
before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent
rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated
version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors
known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not
designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property
damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of
this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered
trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.
The Microchip name and logo, and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISING FROM ANY COURSE OF
DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION, WHETHER BASED ON CONTRACT; TORT;
NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD TO HAVE
FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT SMSC H
Revision 1.1 (02-12-13)
2
DATASHEET
SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
0.1
Reference Documents
Universal Serial Bus Specification, Revision 2.0
USB Battery Charging Specification, Revision 1.1
SMSC USB375x
3
DATASHEET
Revision 1.1 (02-12-13)
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Table of Contents
0.1 Reference Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 1 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2 Pin Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Pin Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Ball/Pin Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 3 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Timing Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1 UVLO and OVLO Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.2 Automatic Charger Detection Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
10
13
13
13
Chapter 4 General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1 VBUS Protection Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1.1 100mA Current Limit (USB375x-1 Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Charger Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.1 Charger Detection Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.2 Automatic Charger Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 USB Mux (USB3750 Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 USB375x Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.1 I2C Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.2 I2C Register Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.2.1 I2C Read Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.2.2 I2C Write Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.3 I2C Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.4 Reg 0: Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.5 Reg 1: Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.6 Reg 2: Battery Charger Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.7 Reg 3: Battery Charger Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18
18
19
20
21
24
24
24
24
24
26
26
27
28
28
29
Chapter 5 Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.1 Application Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 ESD Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.1 Human Body Model (HBM) Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.2 EN/IEC 61000-4-2 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.2.1 Air Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.2.2 Contact Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
31
31
31
32
32
Chapter 6 Package Outline, Tape & Reel Drawings, Package Marking. . . . . . . . . . . . . . . . 33
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DATASHEET
SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
List of Figures
Figure 2.1
Figure 2.2
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4
Figure 4.5
Figure 4.6
Figure 4.7
Figure 4.8
Figure 4.9
Figure 4.10
Figure 5.1
Figure 5.2
Figure 6.1
Figure 6.2
Figure 6.3
Figure 6.4
Figure 6.5
QFN Package Diagram (USB3750) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
QFN Package Diagram (USB3751) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
UVLO and OVLO Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Charger Detection Timing SDP (USB3750-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Charger Detection Timing SDP (USB3751-x) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Charger Detection Timing DCP or CDP (USB3751-x) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Charger Detection Timing SE1 Charger (USB3750-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Charger Detection Timing SE1 Charger (USB3751-x). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
USB3750 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
USB3751 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
USB Charger Detection Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Charger Detection Flow Chart (USB3750-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Charger Detection Flow Chart (USB3751-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Charger Detection Flow Chart (USB3751-2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
I2C Single Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
I2C Continuous Read. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
I2C Single Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
I2C Continuous Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
USB3750 Device Application Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
USB3751 Device Application Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
16-Pin Lead-free QFN Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Tape and Reel Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Reel Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Tape Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Package Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
SMSC USB375x
5
DATASHEET
Revision 1.1 (02-12-13)
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
List of Tables
Table 3.1
Table 3.2
Table 4.1
Table 5.1
Table 6.1
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valid Chargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Values in Application Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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DATASHEET
10
10
19
30
37
SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Chapter 1 General Description
The USB375x integrates many features that have historically been discrete devices in a mobile
product. This device provides significant VBUS protection for the entire system, robust USB interface
ESD protection, a USB 2.0 compliant High Speed switch, and USB-IF Battery Charger Detection
(revision 1.1) capabilities that are essential to the latest mobile products.
Several advanced features allow the USB375x to be optimized for portable applications and to reduce
both eBOM part count and printed circuit board (PCB) area. Outstanding ESD robustness eliminates
the need for external ESD protection devices.
In addition to the integrated ESD protection on the USB interface, the USB375x provides VBUS OverVoltage Protection (OVP).
The USB375x integrated battery charger detection circuitry supports USB-IF Battery Charger
Detection. Battery charger detection will begin automatically whenever VBUS rises above the UVLO
threshold, and can also be completed manually through the I2C interface. The USB375x can detect a
range of USB battery chargers including a Standard Downstream Port (SDP), a Charging Downstream
Port (CDP), and a Dedicated Charging Port (DCP). For more information on USB battery charger
detection, please see the USB Battery Charging Specification, Revision 1.1.
The I2C interface gives processor control over the USB Switch, charger detection, OVLO settings, and
status of the USB375x. In addition, custom charger detection can be implemented through the I2C
interface.
The USB375x family is enabled with SMSC's RapidCharge AnywhereTM which supports USB-IF
Battery Charging 1.1 for any portable device. RapidCharge AnywhereTM provides three times the
charging current through a USB port over traditional solutions which translate up to 1.5Amps via
compatible USB host or dedicated charger. In addition, this provides a complete USB charging
ecosystem between device and host ports such as Dedicated Charging Port (DCP), Charging (CDP)
and Standard (SDP) Downstream Ports.
SMSC USB375x
7
DATASHEET
Revision 1.1 (02-12-13)
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Chapter 2 Pin Layout
2.1
Pin Diagram
DM_1
DP
DM
DP_2
16
15
14
13
The USB375x is available in a QFN (3 x 3 mm) package. The USB3750 pin diagram is detailed in
Figure 2.1. The USB3751 pin diagram is detailed in Figure 2.2.
11
VOUT
VBUS
3
10
VOUT
VBUS
4
9
VOUT
GND
INT_B
8
2
7
VBUS
6
DM_2
SCL
12
5
1
SDA
DP_1
DM_1
DP
DM
NC
16
15
14
13
Figure 2.1 QFN Package Diagram (USB3750)
VBUS
3
10
VOUT
VBUS
4
9
VOUT
8
VOUT
GND
11
7
2
INT_B
VBUS
6
NC
SCL
12
5
1
SDA
DP_1
Figure 2.2 QFN Package Diagram (USB3751)
Revision 1.1 (02-12-13)
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DATASHEET
SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
2.2
Ball/Pin Definitions
The following table details the ball/pin definitions for the package diagrams above.
BALL
PIN
NAME
TYPE/
DIRECTION
DESCRIPTION
15
DP
Analog
USB Mux Output
14
DM
Analog
1
DP_1
Analog
16
DM_1
Analog
13
DP_2
Analog
12
DM_2
Analog
8
GND
Analog
Ground. The QFN package flag should also connected to
ground.
6
SCL
Input
I2C Clock input. This pin is an open drain output and requires a
10Kohm pull-up.
5
SDA
Open Drain/
IO
Bi-Directional I2C data. This pin is an open drain output and
requires a 10Kohm pull-up.
INT_B
Open Drain/
Output
Open Drain Interrupt. This pin is an open drain output that is
pulled low when an interrupt occurs. A 10Kohm pull-up is
required on this pin.
7
9
10
Analog
VOUT
11
2
3
Analog
VBUS
USB Mux Input 1
USB Mux Input 2 (USB3750 Only)
USB3751 should leave these pins unconnected.
Overvoltage switch output. This pin is connected to VBUS when
the overvoltage protection switch is enabled. It is also the output
of the 100mA current limit.
The three VOUT pins must be connected together. When VBUS
is between UVLO and OVLO VOUT is connected to VBUS.
When VBUS is below UVLO or above OVLO the USB375x will
tri-state.
VBUS pin of the USB connector.
The three VBUS pins must be connected together. When the
OVP switch is closed, the VBUS pin will be isolated from VOUT.
When the OVP switch is open, VBUS will be connected to
VOUT. The USB375x is powered from this pin.
4
SMSC USB375x
9
DATASHEET
Revision 1.1 (02-12-13)
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Chapter 3 Electrical Specifications
3.1
Absolute Maximum Ratings
Table 3.1 Absolute Maximum Ratings
DESCRIPTION
RATING
UNIT
VBUS Voltage to GND
-0.3 to 9.0
V
VOUT Voltage to GND
-0.3 to 7.5
V
Any other pin to GND
-0.3 to 5.5
V
Operating Temperature Range
-40 to +85
C
Storage Temperature Range
-55 to +150
C
HBM
8,000
V
IEC-61000-4-2
15,000 (Air)
15,000 (Contact)
V
HBM
1,500
V
ESD Rating
ESD Rating (SDA, SCL, INT_B)
Stresses beyond the Absolute Maximum Ratings may damage the USB375x.
3.2
Electrical Specifications
Table 3.2 Electrical Specifications
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNITS
CONDITIONS
VVBUS = 5.0V, TA = -40C to 85C, all typical values at TA = 27C unless otherwise noted.
VBUS Characteristics
VBUS Operating range
VVBUS
2
VBUS Over Voltage Lockout
VOVLO
6.2
VBUS Under Voltage Lockout
VUVLO
3.3
VBUS Over Voltage Hysteresis
VOVLO
100
mV
VBUS Under Voltage
Hysteresis
VUVLO
100
mV
Operating Current
(OVP open)
IDD_OFF
110
uA
VVBUS < VUVLO
Operating Current
(OVP closed)
IDD_ON
75
115
370
uA
VUVLO < VVBUS < VOVLO
Operating Current
(100mA Limit enabled)
IDD
150
185
480
uA
VUVLO < VVBUS < VOVLO
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V
6.5
6.9
V
3.4
3.8
V
10
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SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNITS
CONDITIONS
VBUS Switch Characteristics
Overvoltage Switch ON
Resistance
RON_VBUS
70
Overvoltage Switch Current
mohm
QFN package
1.8
A
VUVLO < VVBUS < VOVLO
1
uA
VBUS = 5.0V; VOUT = 0V
Overvoltage Switch OFF
Leakage
IOFF_VBUS
VBUS Resistance to Ground
RVBUS
100
Kohm
VBUS Capacitance
CVBUS
1.0
uF
Charger Detection Characteristics 4.4 < VBUS < 5.5V
DP and DM leakage
1
uA
0.0V < Vpin < 3.3V
IDAT_SRC > 250uA
Data Source Voltage
VDAT_SRC
0.5
0.7
V
Data Detect Voltage
VDAT_REF
0.25
0.4
V
Data Connect Detect Current
Source
IDP_SRC
7
13
uA
Data Sink Current
IDAT_SINK
50
150
uA
DP/DM Single Ended RX
Threshold
VSE_RX
0.8
1.95
V
4.75V < VBUS < 5.25V
SE1 High Current Charger RX
Threshold
VSE_RXH
2.1
2.56
V
4.75V < VBUS < 5.25V
DP/DM Pull Down Resistors
RPD
14.25
24.8
Kohm
10
ohm
USB Mux Characteristics (USB3750 Only)
USB Mux On Resistance
RON_USB
2.5
0V < Vin < 3.3V
0V < Vin < 0.4V
USB Mux Off Leakage
IOFF_USB
0.85
uA
On Capacitance
CON_USB
9
pF
Off Capacitance
COFF_USB
6.5
pF
Off Isolation
-35
dB
RL = 50 ohm, F = 250MHz
Crosstalk
-40
dB
RL = 50 ohm, F = 250MHz
1000
MHz
RL = 50 ohm, CL = 0pF
Bandwidth (-3dB)
BW
0V < Vin < 3.3V
800
RL = 50 ohm, CL = 5pF
500
RL = 50 ohm, CL = 10pF
Control Signal Characteristics
Input Logic High Threshold
SMSC USB375x
VIN_H
1.4
V
11
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VBUS > UVLO
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNITS
CONDITIONS
Input Logic Low Threshold
VIN_L
0.4
V
VBUS > UVLO
Output Drive Strength
VOUT_L
0.4
V
VBUS > UVLO, 4.0mA sink
current
nA
0 < Vpin < VOUT
2
mS
Oscillator Accuracy
20
mS
Time to autoclear Soft POR.
Control Signal Leakage
Current
1
Timing Characteristics
Clock Accuracy
TCLK
Soft POR Reset Time
TSOFT_POR
UVLO and OVLO Release
Timer
TVLO_
RELEASE
3
6.5
mS
UVLO and OVLO Engage
Time
TVLO_
ENGAGE
0.5
1.7
mS
Data Contact Detect Timeout
TDCD_TOUT
900
mS
Vdat_src and Idat_sink Enable
Time
TVDPSRC_ON
40
80
160
mS
Delay from Vdat_det to OVP
switch enable
TVDPSRC_HIC
RNT
40
80
160
mS
SE1 Charger Detection wait for
SE1 timer
TCD_SE1
40
80
160
mS
Interrupt Self Clear Timer
TINT
0.5
1
2
mS
Revision 1.1 (02-12-13)
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1
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SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
3.3
Timing Diagrams
3.3.1
UVLO and OVLO Timing
The timing diagram below shows the operation of the OVP switch as VBUS crosses the UVLO and
OVLO thresholds. The behavior of the INT_B signal is also shown in Figure 3.1 below.
OVLO
OVLO
UVLO
VBUS
UVLO
Start Chrg
Detection
VOUT
OVP switch
enabled
OVP switch
disabled
INT_B
OVLO
Fall Int.
OVLO Int.
TVLO_RELEASE
TVLO_ENGAGE
OVP switch
disabled
TINT
TVLO_RELEASE
TINT
TVLO_ENGAGE
Figure 3.1 UVLO and OVLO Timing
3.3.2
Automatic Charger Detection Timing
The timing diagrams below illustrate the automatic charger detection timing that is followed when
implementing the automatic charger detection flow charts shown in this section.
VBUS
UVLO
OVP Switch
Enable
VOUT
USB
VDatDet =0
SDP Detected
X
Connect Detect
USB Mux
Check for SE1
Drive Vdat Source on DP
Mux1 En.
Mux1 and Mux2 Disabled
Mux1 En.
INT_B
Chrg Det
Finish
TVLO_Release
Con. Det. or
T DCD_TOUT
T CD_SE1
TVDPSRC_ON
TVDPSRC_HICRNT
TINT
Figure 3.2 Charger Detection Timing SDP (USB3750-1)
SMSC USB375x
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USB 2.0 Protection IC with Battery Charger Detection
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UVLO
OVP Switch
Enable
(USB3751-2)/
100mA
Current Limit
Enable
(USB3751-1)
VBUS
VOUT
USB
X
VDatDet =0
SDP Detected
Connect Detect
Check for SE1
USB
Pass-Thru
Drive Vdat Source on DP
INT_B
Chrg Det
Finish
Con. Det. or
TDCD_TOUT
TVLO_Release
TCD_SE1
TVDPSRC_ON
TIN
TVDPSRC_HICRNT
T
Figure 3.3 Charger Detection Timing SDP (USB3751-x)
UVLO
OVP Switch
Enable
(USB3751-2)/
100mA
Current limit
Enable
(USB3751-1)
VBUS
VOUT
VDatDet = 1
USB
X
Connect Detect
If VDatDet = 0
CDP detected
If VDatDet = 1
DCP detected
Check for SE1
Drive Vdat
Source on DP
Drive Vdat
Source on DM
USB Tri-State
TCD_SE1
TVDPSRC_ON
TVDPSRC_ON
TVDPSRC_HICRNT
USB
Pass-Thru
INT_B
TVLO_Release
Con. Det. or
TDCD_TOUT
TIN
T
Figure 3.4 Charger Detection Timing DCP or CDP (USB3751-x)
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
VBUS
UVLO
OVP Switch
Enable
VOUT
SE1 Detected
USB
X
Connect Detect
Check for SE1
USB Mux
USB Tri-State
Mux1 and Mux2 Disabled
INT_B
USB
Mux1
Mux1 En.
Chrg Det
Finish
TVLO_Release
Con. Det. or
TDCD_TOUT
TCD_SE1
TVDPSRC_HICRNT
TINT
Figure 3.5 Charger Detection Timing SE1 Charger (USB3750-1)
SMSC USB375x
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
UVLO
OVP Switch
Enable
(USB3751-2)/
100mA
Current Limit
Enable
(USB3751-1)
VBUS
VOUT
SE1 Detected
USB
X
Connect Detect
Check for SE1
INT_B
USB Tri-State
USB
Pass-Thru
Chrg Det
Finish
TVLO_Release
Con. Det. or
TDCD_TOUT
TCD_SE1
TVDPSRC_HICRNT
TIN
T
Figure 3.6 Charger Detection Timing SE1 Charger (USB3751-x)
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SMSC USB375x
USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Chapter 4 General Operation
The USB375x is an integrated USB protection device, battery charger detection device, and High
Speed USB mux (USB3750 only). The USB375x is designed to protect a USB product from electrical
overstress on the USB connector. The USB375x includes several features designed to improve the
reliability and speed the design of products designed with a USB interface.
The USB3750 includes a high bandwidth HS USB mux. The mux allows high speed signals to pass
through and still meet HS USB signaling requirements.
The USB375x will protect the system from ESD stress events on VBUS, DP, and DM. The USB375x
provides ESD protection to the IEC-61000 ESD specification.
The low resistance VBUS overvoltage protection switch protects the internal circuitry from VBUS over
voltage events. When VBUS is outside the safe operating range VBUS switch will automatically open.
The USB375x also includes the capability to detect various USB battery chargers, including those
defined in the USB Battery Charging Specification, Revision 1.1.
To support the device dead battery conditions as defined in the USB Battery Charging Specification,
Revision 1.1, the USB375x-1 has the ability to drive VDAT_SRC on DP which allows a device with a
dead battery to draw 100mA from a USB host. This will allow a device to charge a dead battery without
violating the USB specifications. The USB375x-1 also includes a current limit to prevent the
unconfigured current from exceeding 100mA. Note, this feature is not available with the USB375x-2.
The USB3750 block diagram is shown Figure 4.1 and the USB3751 block diagram is shown Figure 4.2.
DM
VBUS
GND
VBUS
DP_2
DM_2
DP
ESD Protection
USB Connector
USB3750
HS USB
Switch
DP_1
DM_1
DP
DM
DP
DM
VBUS
Over-Voltage/Under-Voltage
Protection and Current
Limiting
Charger
Detection
I2C
Interface
VOUT
SCL
SDA
INT_B
VBUS
USB 2.0 PHY,
Processor, or
Accessory
USB 2.0 PHY,
Processor, or
Accessory
Battery
Charger/
PMU
Processor
Figure 4.1 USB3750 Block Diagram
SMSC USB375x
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
DP
DM
VBUS
GND
ESD Protection
USB Connector
USB3751
DP_1
DM_1
DP
DM
VBUS
Over-Voltage/Under-Voltage
Protection and Current
Limiting
Charger
Detection
I2C
Interface
VOUT
SCL
SDA
INT_B
VBUS
USB 2.0 PHY,
Processor, or
Accessory
Battery
Charger/
PMU
Processor
Figure 4.2 USB3751 Block Diagram
4.1
VBUS Protection Switch
The USB375x protects the entire system from errant VBUS voltages, whether over-voltage or undervoltage conditions. The device is able to dynamically monitor the VBUS voltage levels and take
appropriate action by opening the integrated VBUS Protection Switch when these errant conditions
occur. Specifically, when VBUS is below the Under Voltage Lock-Out (UVLO) level or above the Over
Voltage Lock-Out (OVLO) level, the VBUS switch will open thereby disconnecting the VBUS pin from
VOUT. See Section 3.3 for UVLO and OVLO timing diagrams. Manual control of the VBUS Switch, as
well as switch configuration can be handled through the I2C interface. See Section 4.4.2 for I2C
register descriptions.
4.1.1
100mA Current Limit (USB375x-1 Only)
The USB375x-1 provides a 100mA current limit feature which allows a portable system with a dead
battery to still draw 100mA from a compliant host. When plugged into a Standard Downstream Port
(SDP), the USB375x-1 will enable the 100mA current limit until the system controller enables the OVP
switch in the I2C registers of the USB375x-1. When plugged into any other charger, the USB375x-1
will enable the 100mA current limit during charger detection, and will disable the 100mA current limit
once charger detection has completed. Figure 4.6 details the charger detection flow of the USB375x-1.
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
4.2
Charger Detection
The USB375x includes the circuitry required to implement the USF-IF Battery Charging Specification
(revision 1.1). The USB375x will automatically perform a charger detection upon start-up. The
USB375x includes a state machine to provide the detection of a wide variety of USB charger detection
methods listed in Table 4.1. When any of the USB chargers are plugged into the system, the USB375x
will detect a charger plug in event, determine what type of charger it is, and write the type of charger
information into the I2C register as shown in the following table. In addition, there are two methods to
alert the system that a charger has been detected by the USB375x. The first was through the I2C
register as mentioned above. The second is through the INT_B pin. When a compliant charger is
plugged in and detected, the USB375x will automatically drive the INT_B signal low. Figure 4.4 details
the automatic charger detection flow of the USB3750-1, Figure 4.5 details the automatic charger
detection flow of the USB3751-1, and Figure 4.6 details the automatic charger detection flow of the
USB3751-2.
Table 4.1 Valid Chargers
USB CHARGER TYPE
I2C REG 0
BITS[7:5]
(ChargerType)
DP/DM
PROFILE
DCP
(Dedicated Charging Port, defined in Battery Charging
1.1 specification)
Shorted < 200ohm
001
CDP
(Charging Downstream Port, defined in Battery
Charging 1.1 specification)
VDP reflected to VDM
010
(EnhancedChrgDet = 1)
SDP
(Standard Downstream Port)
USB Host or downstream hub port
15Kohm
pull-down on DP and DM
011
SE1 Charger Low Current Charger
DP = 2.0V
DM = 2.0V
100
(SE1ChrgDet =1)
SE1 Charger High Current Charger
DP = 2.0V
DM = 2.7V
101
(SE1ChrgDet =1)
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
4.2.1
Charger Detection Circuitry
The charger detection circuitry shown Figure 4.3 is used to detect the type charger attached to the
USB connector.
~~
HiCurrent
DpSeRx
DmSeRx
VBUS
SeRxEn
Charger
State
Machine
ContactDetectEn
en
IDP_SRC
DP
VdatSrc
To USB Con.
VdatSrcEn
HostChrgEn
DM
VdatDet
VDAT_REF
RPD
RPD
To USB Con.
en
MUX
I2C
Registers
IdatSinkEn
en
IDAT_SINK
DpPulldownEn
DmPulldownEn
I2C Control
~~
Figure 4.3 USB Charger Detection Block Diagram
Note: The italic names in the Figure 4.3 correspond to bits in the I2C register set.
The VdatDet output is qualified with the Linestate[1:0] value. If the Linestate is not equal to 00b the
VdatDet signal will not assert.
For the USB3750, EnableMux1 or EnableMux2 should not be set while charger detection operations
are performed. During the automatic charger detection EnableMux1 or EnableMux2 will be disabled.
These will need to be disabled by the I2C master if a custom charger detection is performed through
I2C.
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
4.2.2
Automatic Charger Detection
Automatic charger detection will be begin after VBUS crosses the UVLO threshold, and will follow the
flow charts shown below in Figure 4.4 and Figure 4.6. The flow chart timing can be found in
Section 3.3.2. When automatic charger detection has completed, the INT_B signal will go low, and the
type of charger that was detected will be reflected in the ChargerType bits of I2C REG 0 BITS [7:5].
Start Chrg Detection
ChrgDetComplete = 0
UVLO < VBUS < OVLO
Start TVLO_RELEASE
Enable IDP_SRC
and RPD_DM
Enable
100mA after
TVLO_RELEASE
Release and
wait TCD_SE1
SE1?
Any UVLO or OVLO Exit Chrg Detection
Wait for DP
Low or
TDCD_TOUT
Disable
IDP_SRC
and RPD_DM
=1
=0
Drive DP
VDAT_SRC for
TVDPSRC_ON
=0
VDAT
Detect?
=1
RxHiCurr?
=0
=1
Drive DM
VDAT_SRC for
TVDPSRC_ON
VDAT
Detect?
=0
=1
SDP
Detected
DCP
Detected
CDP
Detected
SE1 High
Current
Charger
Clear Charger
Detection
Register
Wait
TVDPSRC_HICRNT
Enable OVP
Switch
SE1 Low
Current
Charger
Disable
100mA
current limit
Default USB
Mux setting
Exit Chrg Detection
ChrgDetComplete = 1
Figure 4.4 Charger Detection Flow Chart (USB3750-1)
SMSC USB375x
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Start Chrg Detection
ChrgDetComplete = 0
UVLO < VBUS < OVLO
Start TVLO_RELEASE
Enable IDP_SRC
and RPD_DM
Enable
100mA after
TVLO_RELEASE
Release and
wait TCD_SE1
SE1?
Any UVLO or OVLO Exit Chrg Detection
Wait for DP
Low or
TDCD_TOUT
Disable
IDP_SRC
and RPD_DM
=1
=0
Drive DP
VDAT_SRC for
TVDPSRC_ON
=0
VDAT
Detect?
=1
=1
RxHiCurr?
=0
Drive DM
VDAT_SRC for
TVDPSRC_ON
VDAT
Detect?
=0
=1
SDP
Detected
DCP
Detected
CDP
Detected
SE1 High
Current
Charger
Clear Charger
Detection
Register
Wait
TVDPSRC_HICRNT
Enable OVP
Switch
SE1 Low
Current
Charger
Disable
100mA
current limit
Exit Chrg Detection
ChrgDetComplete = 1
Figure 4.5 Charger Detection Flow Chart (USB3751-1)
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
Start Chrg Detection
ChrgDetComplete = 0
UVLO < VBUS < OVLO
Start TVLO_RELEASE
Enable IDP_SRC
and RPD_DM
Any UVLO or OVLO Exit Chrg Detection
Wait for DP
Low or
TDCD_TOUT
Disable
IDP_SRC
and RPD_DM
Release and
wait TCD_SE1
SE1?
=1
=0
Drive DP
VDAT_SRC for
TVDPSRC_ON
=0
VDAT
Detect?
=1
=1
RxHiCurr?
=0
Drive DM
VDAT_SRC for
TVDPSRC_ON
VDAT
Detect?
=0
=1
SDP
Detected
DCP
Detected
CDP
Detected
SE1 High
Current
Charger
Clear Charger
Detection
Register
Wait
TVDPSRC_HICRNT
Enable OVP
Switch
SE1 Low
Current
Charger
Exit Chrg Detection
ChrgDetComplete = 1
Figure 4.6 Charger Detection Flow Chart (USB3751-2)
SMSC USB375x
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USB 2.0 Protection IC with Battery Charger Detection
Datasheet
4.3
USB Mux (USB3750 Only)
The USB mux is designed to pass High Speed USB signals to the USB connector, and allows for two
USB inputs to be multiplexed into one USB output. Either switch path is enabled through the I2C
interface, and the switch paths are disabled in the event of UVLO or OVLO.
The USB Mux is designed to pass USB signals from 0 to 3.3V. It is not designed to pass signals that
go above 3.3V or below ground.
During power-up and charger detection the USB Mux switches will be disabled regardless of the
EnableMux1 and EnableMux2 settings.
Once power-up and charger detection are complete EnableMux1 is enabled by default.
4.4
USB375x Registers
All registers are reset when VBUS goes below UVLO. All registers are accessed through the I2C
interface defined below.
4.4.1
I2C Interface
The SDA and SCL pins comprise the I2C interface of the USB375x. The I2C master controls all traffic
to the USB375x. If the USB375x has a change in status it can assert the INT_B by pulling this line to
ground. The USB375x INT_B line will stay low and then auto-clear after 1mS or until cleared by
reading the Status Register. This prevents INT_B from masking other interrupts if the line is shared
with other I2C devices.
SCL, SDA, and INT_B will be tri-stated until VBUS is above the UVLO. VBUS must be present to
operate the I2C interface.
SCL is an input only pad. SDA is bi-directional and can be configured as an input or an open drain
output during I2C operations.
SDA, and INT_B are open collector when configured as an output. This requires an external pull-up
resistor on SDA and INT_B.
The USB375x-1 requires I2C communications in order for the default USB path to be enabled. By
default, the 100mA current limit is enabled. Only devices that draw
