The ISP1122A is a stand-alone Universal Serial Bus (USB) hub device which
complies with
(SIE), hub repeater, hub controller, USB data transceivers and a 3.3 V voltage
regulator. It has a configurable number of downstream ports, ranging from 2 to 5.
The ISP1122A can be bus-powered, self-powered or hybrid-powered. When it is
hybrid-poweredthe hub functions are poweredby the upstream power supply (V
but the downstream ports are powered by an external 5 Volt supply. The low power
consumption in ‘suspend’ mode allows easy design of equipment that is compliant
with the ACPI™, OnNow™ and USB power management requirements.
The ISP1122A has built-in overcurrent sense inputs, supporting individual and global
overcurrent protection for downstream ports. All ports (including the hub) have
GoodLink™ indicator outputs foreasy visual monitoring of USB traffic. The ISP1122A
has a serial I2C-bus interface for external EEPROM access and a reduced frequency
(6 MHz) crystal oscillator. These features allow significant cost savings in system
design and easy implementation of advanced USB functionality into PC peripherals.
USB Specification Rev. 1.1
. It integrates a Serial Interface Engine
BUS
),
2.Features
■ High performance USB hub device with integrated hub repeater, hub controller,
Serial Interface Engine (SIE), data transceivers and 3.3 V voltage regulator
■ Complies with
USB power management requirements
■ Configurable from 2 to 5 downstream ports with automatic speed detection
■ Internal power-on reset and low voltage reset circuit
■ Supports bus-powered, hybrid-powered and self-powered application
■ Individual or ganged power switching for downstream ports
■ Individual or global port overcurrent protection with built-in sense circuits
■ 6 MHz crystal oscillator with on-chip PLL for low EMI
■ Visual USB traffic monitoring (GoodLink™) for hub and downstream ports
■ I2C-bus interface to read vendor ID, product ID and configuration bits from
external EEPROM
■ Operation over the extended USB bus voltage range (4.0 to 5.5 V)
■ Operating temperature range −40 to +85 °C
■ 8 kV in-circuit ESD protection for lower cost of external components
■ Full-scan design with high test coverage
■ Available in 32-pin SDIP, SO and LQFP packages.
Universal Serial Bus Specification Rev. 1.1
and ACPI, OnNow and
Page 2
Philips Semiconductors
ISP1122A
USB stand-alone hub
3.Ordering information
Table 1:Ordering information
Type numberPackage
NameDescriptionVersion
ISP1122ADSO32plastic small outline package; 32 leads; body width 7.5 mmSOT287-1
ISP1122ANBSDIP32plastic shrink dual in-line package; 32 leads (400 mil)SOT232-1
ISP1122ABDLQFP32plastic low profile quad flat package; 32 leads; body 7 x 7 x 1.4 mmSOT358-1
4.Block diagram
pagewidth
upstream
ISP1122A
V
CC
5 V
SUPPLY
REGULATOR
3.3 V
V
reg(3.3)
port
D+ D−
ANALOG
Tx/Rx
full
speed
LED
HUB
GoodLink
6 MHz
PLL
BIT CLOCK
RECOVERY
PHILIPS
SIE
PACKET
GENERATOR
HUB
CONTROLLER
INDV
OPTION
I2C-BUS
INTERFACE
SDA
SCL
HUB
REPEATER
ANALOG
Tx/Rx
POWER SWITCH/
OC DETECT
D+ D− overcurrent
detection
downstream
port 1
GoodLink/
power switch
LED/
ANALOG
Tx/Rx
POWER SWITCH/
OC DETECT
D+ D− overcurrent
detection
downstream
port 2
GoodLink/
power switch
LED/
ANALOG
Tx/Rx
POWER SWITCH/
OC DETECT
D+ D− overcurrent
detection
downstream
port 3
GoodLink/
power switch
LED/
This is a conceptual block diagram and does not include each individual signal.
21Ireset input (Schmitt trigger); a LOW level produces an
asynchronous reset; connect to V
for power-on reset
CC
(internal POR circuit)
2
OPTION/SCL 22I/Omode selection input; also functions as I
C-bus clock output
(open-drain, 6 mA)
INDV/SDA23I/Oselects individual (HIGH) or global (LOW) power switching
and overcurrent detection; also functions as bidirectional
2
C-bus data line (open-drain, 6 mA)
I
DM524AI/Odownstream port 5 D− connection (analog)
DP525AI/Odownstream port 5 D+ connection (analog)
DM126AI/Odownstream port 1 D− connection (analog)
DP127AI/Odownstream port 1 D+ connection (analog)
DM028AI/Oupstream port D− connection (analog)
DP029AI/Oupstream port D+ connection (analog)
DM230AI/Odownstream port 2 D− connection (analog)
DP231AI/Odownstream port 2 D+ connection (analog)
PSW1/GL1
[3]
32Omodes 4 to 6: power switch control output for downstream
[6]
[6]
port 1 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 1 (open-drain, 6 mA); to connect an LED
use a 330 Ω series resistor
[1] Symbol names with an overscore (e.g. NAME) indicate active LOW signals.
[2] The voltage at pin V
connecting RESET to V
[3] See Table 4 “Mode selection”.
[4] To disable a downstream port connect both D+ and D− to VCCvia a 1 MΩ resistor; unused ports must
be disabled in reverse order starting from port 5.
[5] Analog detection circuit can be switched off using an external EEPROM, see Table 23; in this case,
the pin functions as a logic input (TTL level).
[6] Downstream ports 1 and 2 cannot be disabled.
is gated by the RESET pin. This allows fully self-powered operation by
GND31-ground supply
DM332AI/Odownstream port 3 D− connection (analog)
DP31AI/Odownstream port 3 D+ connection (analog)
V
OC13AI/Iovercurrent sense input for downstream port 1 (analog
OC24AI/Iovercurrent sense input for downstream port 2 (analog
OC35AI/Iovercurrent sense input for downstream port 3 (analog
OC46AI/Iovercurrent sense input for downstream port 4 (analog
9397 750 08958
Product dataRev. 03 — 30 October 20016 of 48
Page 7
Philips Semiconductors
ISP1122A
USB stand-alone hub
Table 3:Pin description for LQFP32
Symbol
OC5/GOC
[1]
PinType Description
[3]
7AI/Imodes 5, 7: overcurrent sense input for downstream port 5
(analog
modes 0, 1, 3: global overcurrent sense input (analog
DM48AI/Odownstream port 4 D− connection (analog)
DP49AI/Odownstream port 4 D+ connection (analog)
…continued
[5]
)
[5]
[4]
[4]
SP/BP10Iselects power mode:
self-powered: connect to V
(local power supply); also use
DD
this mode for hybrid-powered operation
bus-powered:connect to GND; disable downstream port 5 to
meet supply current requirements
[4]
HUBGL11Ohub GoodLink LED indicator output (open-drain, 6 mA);
to connect an LED use a 330 Ω series resistor; if unused
via a 10 kΩ resistor
CC
PSW3/GL3
connect to V
[3]
12Omodes 4 to 6: power switch control output for downstream
port 3 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 3 (open-drain, 6 mA); to connect an LED
use a 330 Ω series resistor
PSW4/GL4
[3]
13Omodes 4 to 6: power switch control output for downstream
port 4 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 4 (open-drain, 6 mA); to connect an LED
use a 330 Ω series resistor
PSW5/GL5/
[3]
GPSW
14Omode 5: power switch control output for downstream port 5
(open-drain, 6 mA)
modes 3, 7: GoodLink LED indicator output for downstream
port 5 (open-drain, 6 mA); to connect an LED use a 330 Ω
series resistor
modes 0 to 2: gang mode power switch control output
17Ireset input (Schmitt trigger); a LOW level produces an
asynchronous reset; connect to V
for power-on reset
CC
(internal POR circuit)
2
OPTION/SCL 18I/Omode selection input; also functions as I
C-bus clock output
(open-drain, 6 mA)
INDV/SDA19I/Oselects individual (HIGH) or global (LOW) power switching
and overcurrent detection; also functions as bidirectional
2
C-bus data line (open-drain, 6 mA)
I
DM520AI/Odownstream port 5 D− connection (analog)
DP521AI/Odownstream port 5 D+ connection (analog)
DM122AI/Odownstream port 1 D− connection (analog)
DP123AI/Odownstream port 1 D+ connection (analog)
[4]
[4]
[6]
[6]
DM024AI/Oupstream port D− connection (analog)
DP025AI/Oupstream port D+ connection (analog)
DM226AI/Odownstream port 2 D− connection (analog)
DP227AI/Odownstream port 2 D+ connection (analog)
PSW1/GL1
[1] Symbol names with an overscore (e.g. NAME) indicate active LOW signals.
[2] The voltage at pin V
[3] See Table 4 “Mode selection”.
[4] To disable a downstream port connect both D+ and D− to VCCvia a 1 MΩ resistor; unused ports must
[5] Analog detection circuit can be switched off using an external EEPROM, see Table 23; in this case,
[6] Downstream ports 1 and 2 cannot be disabled.
[1]
connecting RESET to V
be disabled in reverse order starting from port 5.
the pin functions as a logic input (TTL level).
6.Functional description
The ISP1122A is a stand-alone USB hub with up to 5 downstream ports. The number
of ports can be configured between 2 and 5. The downstream ports can be used to
connect low-speed or full-speed USB peripherals. All standard USB requests from
the host are handled by the hardware without the need for firmware intervention. The
block diagram is shown in Figure 1.
…continued
PinType Description
[6]
[6]
[3]
28Omodes 4 to 6: power switch control output for downstream
port 1 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 1 (open-drain, 6 mA); to connect an LED
use a 330 Ω series resistor
is gated by the RESET pin. This allows fully self-powered operation by
reg(3.3)
(+5 V USB supply). If V
BUS
is lost upstream port D+ will not be driven.
BUS
The ISP1122A requires only a single supply voltage. An internal 3.3 V regulator
provides the supply voltage for the analog USB data transceivers.
The ISP1122A supports both bus-powered and self-powered hub operation. When
using bus-powered operation a downstream port cannot supply more than 100 mA to
a peripheral. In case of self-powered operation an external supply is used to power
the downstream ports, allowing a current consumption of max. 500 mA per port.
A basic I2C-bus interface is provided for reading vendor ID, product ID and
configuration bits from an external EEPROM upon a reset.
6.1 Analog transceivers
The integrated transceiver interfaces directly to the USB cables through external
termination resistors. They are capable of transmitting and receiving serial data at
both ‘full-speed’ (12 Mbit/s) and ‘low-speed’ (1.5 Mbit/s) data rates. The slew rates
are adjusted according to the speed of the device connected and lie within the range
mentioned in the
The Philips SIE implements the full USB protocol layer. It is completely hardwired for
speed and needs no firmware intervention. The functions of this block include:
synchronization pattern recognition, parallel/serial conversion, bit (de-)stuffing, CRC
checking/generation, Packet IDentifier (PID) verification/generation, address
recognition, handshake evaluation/generation.
6.3 Hub repeater
The hub repeater is responsible for managing connectivity on a ‘per packet’ basis. It
implements ‘packet signalling’ and ‘resume’ connectivity. Low-speed devices can be
connected to downstream ports. If a low-speed device is detected the repeater will
not propagate upstream packets to the corresponding port, unless they are preceded
by a PREAMBLE PID.
6.4 End-of-frame timers
This block contains the specified EOF1 and EOF2 timers which are used to detect
‘loss-of-activity’ and ‘babble’ error conditions in the hub repeater. The timers also
maintain the low-speed keep-alive strobe which is sent at the beginning of a frame.
ISP1122A
USB stand-alone hub
6.5 General and individual port controller
The general and individual port controllers together provide status and control of
individual downstream ports. Any port status change will be reported to the host via
the hub status change (interrupt) endpoint.
6.6 GoodLink
Indication of a good USB connection is provided through GoodLink technology. An
LED can be directly connected via an external 330 Ω resistor.
During enumeration the LED blinks on momentarily. After successful configuration of
the ISP1122A, the LED is permanently on. The LED blinks off for 100 ms upon each
successful packet transfer (with ACK). The hub GoodLink indicator blinks when the
hub receives a packet addressed to it. Downstream GoodLink indicators blink upon
an acknowledgment from the associated port. In ‘suspend’ mode the LED is off.
This feature provides a user-friendly indication of the status of the hub, the connected
downstream devices and the USB traffic. It is a useful diagnostics tool to isolate faulty
USB equipment and helps to reduce field support and hotline costs.
6.7 Bit clock recovery
The bit clock recovery circuit recovers the clock from the incoming USB data stream
using a 4× oversampling principle. It is able to track jitter and frequency drift as
specified by the
USB Specification Rev. 1.1
.
6.8 Voltage regulator
A 5 to 3.3 V DC-DC regulator is integrated on-chip to supply the analog transceiver
and internal logic. This can also be used to supply the terminal 1.5 kΩ pull-up resistor
on the D+ line of the upstream connection.
A 6 to 48 MHz clock multiplier Phase-Locked Loop (PLL) is integrated on-chip. This
allows for the use of low-cost 6 MHz crystals. The low crystal frequency also
minimizes Electro-Magnetic Interference (EMI). The PLL requires no external
components.
6.10 Overcurrent detection
An overcurrent detection circuit for downstream ports has been integrated on-chip. It
is self-reporting, resets automatically, has a low trip time and requires no external
components. Both individual and global overcurrent detection are supported.
6.11 I2C-bus interface
A basic serial I2C-bus interface (single master, 100 kHz) is provided to read VID, PID
and configuration bits from an external I2C-bus EEPROM (e.g. Philips PCF8582 or
equivalent). At reset the ISP1122A reads 6 bytes of data from the external memory.
The I2C-bus interface timing complies with the standard mode of operation as
described in
The I2C-bus and how to use it
ISP1122A
USB stand-alone hub
, order number 9398 393 40011.
7.Modes of operation
The ISP1122A has several modes of operation, each corresponding with a different
pin configuration. Modes are selected by means of pins INDV, OPTION and SP/BP,
as shown in Table 4.
Each USB device is logically composed of several independent endpoints. An
endpoint acts as a terminus of a communication flow between the host and the
device. At design time each endpoint is assigned a unique number (endpoint
identifier, see Table 5). The combination of the device address (given by the host
during enumeration), the endpoint number and the transfer direction allows each
endpoint to be uniquely referenced.
The ISP1122A has two endpoints, endpoint 0 (control) and endpoint 1 (interrupt).
Table 5:Hub endpoints
FunctionPortsEndpoint
Hub
[1] IN: input for the USB host; OUT: output from the USB host.
0: upstream
1 to 5: downstream
ISP1122A
USB stand-alone hub
identifier
0control
1interruptIN1
Transfer
type
Direction
OUT64
IN64
[1]
Max. packet
size (bytes)
8.1 Hub endpoint 0 (control)
All USB devices and functions must implement a default control endpoint (ID = 0).
This endpoint is used by the host to configure the device and to perform generic USB
status and control access.
The ISP1122A hub supports the following USB descriptor information through its
control endpoint 0, which can handle transfers of 64 bytes maximum:
Device descriptor
•
Configuration descriptor
•
Interface descriptor
•
Endpoint descriptor
•
Hub descriptor
•
String descriptor.
•
8.2 Hub endpoint 1 (interrupt)
Endpoint 1 is used by the ISP1122A hub to provide status change information to the
host. This endpoint can be accessed only after the hub has been configured by the
host (by sending the Set Configuration command).
Endpoint 1 is an interrupt endpoint: the host polls it once every 255 ms by sending an
IN token. If the hub has detected no change in the port status it returns a NAK (Not
AcKnowledge) response to this request, otherwise it sends the Status Change byte
(see Table 6).
0Hub SCa logic 1 indicates a status change on the hub’s upstream port
1Port 1 SCa logic 1 indicates a status change on downstream port 1
2Port 2 SCa logic 1 indicates a status change on downstream port 2
3Port 3 SCa logic 1 indicates a status change on downstream port 3
4Port 4 SCa logic 1 indicates a status change on downstream port 4
5Port 5 SCa logic 1 indicates a status change on downstream port 5
6reservednot used
7reservednot used
9.Host requests
The ISP1122A handles all standard USB requests from the host via control
endpoint 0. The control endpoint can handle a maximum of 64 bytes per transfer.
Remark: Please note that the USB data transmission order is Least Significant Bit
(LSB) first. In the following tables multi-byte variables are displayed least significant
byte first.
ISP1122A
USB stand-alone hub
9.1 Standard requests
Table 7 shows the supported standard USB requests. Some requests are explicitly
unsupported. All other requests will be responded to with a STALL packet.
Table 7:Standard USB requests
Request namebmRequestType
Address
Set AddressX000 000005address
Configuration
Get Configuration1000 00000800, 0000, 0001, 00configuration
Set Configuration (0)X000 00000900, 0000, 0000, 00none
Set Configuration (1)X000 00000901, 0000, 0000, 00none
Descriptor
Get Configuration
Descriptor
Get Device Descriptor1000 00000600, 0100, 00length
Get String Descriptor (0)1000 00000603, 0000, 00length
Get String Descriptor (1)1000 00000603, 0100, 00length
Get String Descriptor (2)1000 00000603, 0200, 00length
Get Device Status1000 00000000, 0000, 0002, 00device status
Get Interface Status1000 00010000, 0000, 0002, 00zero
[3]
Get Endpoint (0) Status1000 00100000, 0000/80
, 0002, 00endpoint 0
status
Get Endpoint (1) Status1000 00100000, 0081, 0002, 00endpoint 1
status
Unsupported
Set Descriptor0000 000007XX, XXXX, XXXX, XXdescriptor;
STALL
Get Interface1000 00010A00, 00XX, XX01, 00STALL
Set InterfaceX000 00010BXX, XXXX, XX00, 00STALL
Synch Frame1000 00100C00, 00XX, XX02, 00STALL
[1] Device address: 0 to 127.
[2] Returned value in bytes.
[3] MSB specifies endpoint direction: 0 = OUT, 1 = IN. The ISP1122A accepts either value.
9.2 Hub specific requests
In Table 8 the supported hub specific requests are listed, as well as some
unsupported requests. Table 9 provides the feature selectors for setting or clearing
port features.
PORT_CONNECTION00not usednot used
PORT_ENABLE01not useddisables a port
PORT_SUSPEND02suspends a portresumes a port
PORT_OVERCURRENT03not usednot used
PORT_RESET04resets and enables a
not used
port
PORT_POWER08powers on a portpowers off a port
PORT_LOW_SPEED09not usednot used
C_PORT_CONNECTION10not usedclears port connection
change bit
C_PORT_ENABLE11not usedclears port enable
change bit
C_PORT_SUSPEND12not usedclears port suspend
change bit
C_PORT_OVERCURRENT 13not usedclears port overcurrent
The hub returns 4 bytes. The first 2 bytes contain the port status bits (wPortStatus,
see Table 20). The last 2 bytes hold the port status change bits (wPortChange, see
The hub returns 25 bytes containing the configuration descriptor (9 bytes, see
Table 11), the interface descriptor (9 bytes, see Table 12) and the endpoint descriptor
(7 bytes, see Table 13).
9.4.7 Get device descriptor
The hub returns 18 bytes containing the device descriptor, see Table 10.
9.4.8 Get hub descriptor
The hub returns 9 bytes containing the hub descriptor, see Table 14.
9.4.9 Get string descriptor (0)
The hub returns 4 bytes containing the language ID, see Table 15.
9.4.10 Get string descriptor (1)
The hub returns 46 bytes containing the manufacturer name, see Table 15.
9.4.11 Get string descriptor (2)
The hub returns 16 bytes containing the product name, see Table 15.
ISP1122A
USB stand-alone hub
10. I2C-bus interface
A simple I2C-bus interface is provided in the ISP1122A to read customized vendor ID,
product ID and some other configuration bits from an external EEPROM. The
interface supports single master operation at a nominal bus speed of 93.75 kHz.
The I2C-bus interface is intended for bidirectional communication between ICs via two
serial bus wires, SDA (data) and SCL (clock). Both lines are driven by open-drain
circuits and must be connected to the positive supply voltage via pull-up resistors.
10.1 Protocol
The I2C-bus protocol defines the following conditions:
•
•
•
•
Each device on the I2C-bus has a unique slave address, which the master uses to
select a device for access.
The master starts a data transfer using a START condition and ends it by generating
a STOP condition. Transfers can only be initiated when the bus is free. The receiver
must acknowledge each byte by means of a LOW level on SDA during the ninth clock
pulse on SCL.
Bus free: both SDA and SCL are HIGH
START: a HIGH-to-LOW transition on SDA, while SCL is HIGH
STOP: a LOW-to-HIGH transition on SDA, while SCL is HIGH
Data valid: after a START condition, data on SDA are stable during the HIGH
period of SCL; data on SDA may only change while SCL is LOW.
For detailed information please consult
9398 393 40011.
Via the I2C-bus interface the ISP1122A can be connected to an external EEPROM
(PCF8582 or equivalent). The hardware connections are shown in Figure 5.
The SCL and SDA pins are multiplexed with pins OPTION and INDV respectively.
ISP1122A
USB stand-alone hub
dth
Fig 5. EEPROM connection diagram.
The slaveaddress which ISP1122A uses to access the EEPROM is 1010000B. Page
mode addressing is not supported, so pins A0, A1 and A2 of the EEPROM must be
connected to GND (logic 0).
10.3 Data transfer
When the ISP1122A is reset, the I2C-bus interface tries to read 6 bytes of
configuration data from an external EEPROM. If no response is detected, the levels
on inputs SDA and SCL are interpreted as INDV and OPTION to select the operating
mode (see Table 4).
OPTION/SCL
INDV/SDA
ISP1122A
USB HUB
V
DD
R
2
I
P
C-bus
V
DD
R
P
SCL
SDA
PCF8582
EEPROM
equivalent
A0
A1
A2
or
MBL166
The data in the EEPROM memory are organized as shown in Table 22.
Table 22: EEPROM organization
Address
(Hex)
00CCidVendor
0104idVendor
0222idProduct
0311idProduct
04-configuration bits C7 to C0; see Table 23
05AAsignature
[1] Vendor ID code in the Device descriptor, seeTable 10.
[2] Product ID code in the Device descriptor, see Table 10.
00
1X500 mA (MaxPower= FAH)
010 mA (MaxPower= 00H)
Description
must always be programmed to logic 0
100 ms (bPwrOn2PwrGood = 32H)
string descriptors disabled
“Philips Semiconductors”, “ISP1122”)
circuit disabled; overcurrent pins
function as digital inputs (TTL level)
internal analog overcurrent detection
circuit enabled
100 mA (MaxPower= 32H)
OCn
[1] Default value at reset if no external EEPROM is present.
[2] Modifies the Hub Descriptor field ‘bPwrOn2PwrGood’, see Table 14.
[3] Modifies the Hub Descriptor field ‘MaxPower’, seeTable 14.
11. Hub power modes
USB hubs can either be self-powered or bus-powered.
Self-powered — Self-powered hubs have a 5 V local power supply on board which
provide power to the hub and the downstream ports. The
requires that these hubs limit the current to 500 mA per downstream port and report
overcurrent conditions to the host. The hub may optionally draw 100 mA from the
USB supply (V
Bus-powered — Bus-powered hubs obtain all power from the host or an upstream
self-powered hub. The maximum current is 100 mA per downstream port. Current
limiting and reporting of overcurrent conditions are both optional.
Power switching of downstream ports can be done individually or ganged, where all
ports are switched simultaneously with one power switch. The ISP1122A supports
both modes, which can be selected using input INDV (see Table 4).
11.1 Voltage drop requirements
USB Specification Rev. 1.1
) to power the interface functions (hybrid-powered).
BUS
11.1.1 Self-powered hubs
Self-powered hubs are required to provide a minimum of 4.75 V to its output port
connectors at all legal load conditions. To comply with Underwriters Laboratory Inc.
(UL) safety requirements, the power from any port must be limited to 25 W (5 A at
5 V). Overcurrent protection may be implemented on a global or individual basis.
Assuming a 5 V ± 3% power supply the worst case supply voltage is 4.85 V. This only
allows a voltage drop of 100 mV across the hub printed-circuit board (PCB) to each
downstream connector. This includes a voltage drop across:
•
•
•
•
PCB resistance and power supply connector resistance may cause a drop of 25 mV,
leaving only 75 mV as the voltage drop allowed across the power switch and
overcurrent sense device. The individual voltage drop components are shown in
Figure 6.
ISP1122A
USB stand-alone hub
Power supply connector
Hub PCB (power and ground traces, ferrite beads)
Power switch (FET on-resistance)
Overcurrent sense device.
voltage drop
25 mV
hub board
resistance
4.75 V(min)
(1)
V
BUS
D+
D−
GND
SHIELD
04aa03
downstream
port
connector
5 V
POWER SUPPLY
± 3% regulated
(1) Includes PCB traces, ferrite beads, etc.
+
−
4.85 V(min)
voltage drop
ISP1122A
power
switch
75 mV
low-ohmic
PMOS switch
Fig 6. Typical voltage drop components in self-powered mode using individual overcurrent detection.
In case of global overcurrent detection an increased voltage drop is needed for the
overcurrent sense device (in this case a low-ohmic resistor). This can be realized by
using a special power supply of 5.1 V ± 3%, as shown in Figure 7.
voltage drop
5.1 V KICK-UP
POWER SUPPLY
± 3% regulated
(1) Includes PCB traces, ferrite beads, etc.
4.95 V(min)
+
−
100 mV
low-ohmic
sense resistor
for overcurrent
detection
voltage drop
ISP1122A
power
switch
75 mV
low-ohmic
PMOS switch
Fig 7. Typical voltage drop components in self-powered mode using global overcurrent detection.
voltage drop
25 mV
hub board
resistance
4.75 V(min)
(1)
V
BUS
D+
D−
GND
SHIELD
04aa05
downstream
port
connector
11.1.2 Bus-powered hubs
Bus-powered hubs are guaranteed to receive a supply voltage of 4.5 V at the
upstream port connector and must provide a minimum of 4.4 V to the downstream
port connectors. The voltage drop of 100 mV across bus-powered hubs includes:
The PCB resistance may cause a drop of 25 mV, which leaves 75 mV for the power
switch and overcurrent sense device. The voltage drop components are shown in
Figure 8.
For bus-powered hubs overcurrent protection is optional. It may be implemented for
all downstream ports on a global or individual basis.
ISP1122A
USB stand-alone hub
voltage drop
25 mV
hub board
resistance
4.40 V(min)4.50 V(min)
(1)
V
BUS
upstream
port
connector
(1) Includes PCB traces, ferrite beads, etc.
D+
D−
GND
SHIELD
voltage drop
ISP1122A
power
switch
75 mV
low-ohmic
PMOS switch
Fig 8. Typical voltage drop components in bus-powered mode (no overcurrent detection).
12. Overcurrent detection
The ISP1122A has an analog overcurrent detection circuit for monitoring downstream
port lines. This circuit automatically reports an overcurrent condition to the host and
turns off the power to the faulty port. The host must reset the condition flag.
Pins OC1 to OC5/GOC are used for individual port overcurrent detection. Pin
OC5/GOC can also be used for global overcurrent detection. This is controlled by
input INDV (see Table 4).
The overcurrent detection circuit can be switched off using an external EEPROM (see
Table 23). In this case, the overcurrent pins OCn function as logic inputs (TTL level).
V
BUS
D+
D−
GND
SHIELD
04aa06
downstream
port
connector
12.1 Overcurrent circuit description
The integrated overcurrent detection circuit of ISP1122A senses the voltage drop
across the power switch or an extra low-ohmic sense resistor. When the port draws
too much current, the voltage drop across the power switch exceeds the trip voltage
threshold (∆V
switch control signal after a delay of 15 ms (t
). The overcurrent circuit detects this and switches off the power
trip
). This delay acts as a ‘debounce’
trip
period to minimize false tripping, especially during the inrush current produced by ‘hot
plugging’ of a USB device.
12.2 Power switch selection
From the voltage drop analysis given in Figure 6, Figure 7 and Figure 8, the power
switch has a voltage drop budget of 75 mV. For individual self-powered mode, the
current drawn per port can be up to 500 mA. Thus the power switch should have
maximum on-resistance of 150 mΩ.
If the voltage drop due to the hub board resistance can be minimized, the power
switch can have more voltage drop budget and therefore a higher on-resistance.
Power switches with a typical on-resistance of around 100 mΩ fit into this application.
The ISP1122A overcurrent detection circuit has been designed with a nominal trip
voltage (∆V
a power switch with an on-resistance of 100 mΩ1.
12.3 Tuning the overcurrent trip voltage
The ISP1122A trip voltage can optionally be adjusted through external components
to set the desired trip current. This is done by inserting tuning resistors at pins SP/BP
or OCn (see Figure 9). Rtu tunes up the trip voltage ∆V
according to Equation 1.
ISP1122A
USB stand-alone hub
) of 85 mV. This gives a typical trip current of approximately 850 mA for
trip
and Rtd tunes it down
trip
handbook, halfpage
V
CC
I
=5µA
ref(nom)
I
= 0.5 µA
OC(nom)
VCCSP/BP
∆V
with I
I
ref
R
tu
ISP1122A
trip
ref(nom)
low-ohmic
PMOS switch
OCn
∆V
trip intrinsic()IrefRtu
=5µA and I
I
OC
R
td
MBL167
OC(nom)
⋅IOCRtd⋅–+=
= 0.5 µA.
handbook, halfpage
V
BUS
I
OC(nom)
VCCSP/BP
= 0.5 µA
a. Self-powered mode.b. Bus-powered mode.
Fig 9. Tuning the overcurrent trip voltage.
12.4 Reference circuits
ISP1122A
low-ohmic
PMOS switch
R
OCn
MBL168
(1)
I
OC
td
Some typical examples of port power switching and overcurrent detection modes are
given in Figure 10 to Figure 13.
The RC circuit (47 kΩ and 0.1 µF) around the PMOS switch provides for soft turn-on.
The series resistor connecting the SP/BP pin to VCC tunes up the overcurrent trip
voltage slightly (see Figure 9). In the schematic diagram the resistor separates the
net names for pins VCC and SP/BP. This allows an automatic router to use a wide
trace for VCC and a narrow trace to connect pin SP/BP.
1.The following PMOS power switches have been tested to work well with the ISP1122A: Philips PHP109, Vishay Siliconix Si2301DS,
Fairchild FDN338P.
Table 29: Static characteristics: analog I/O pins (D+, D−)
VCC= 4.0 to 5.5 V; V
GND
=0V; T
=−40 to+85°C; unless otherwise specified.
amb
[1]
SymbolParameterConditionsMinTypMaxUnit
Input levels
V
DI
V
CM
differential input sensitivity|V
differential common mode
− V
I(D+)
|0.2--V
I(D−)
includes VDI range0.8-2.5V
voltage
V
IL
V
IH
LOW-level input voltage--0.8V
HIGH-level input voltage2.0--V
Output levels
V
OL
V
OH
LOW-level output voltageRL= 1.5 kΩ to +3.6V--0.3V
HIGH-level output voltageRL=15kΩ to GND2.8-3.6V
Leakage current
I
LZ
OFF-state leakage current--±10µA
Capacitance
C
IN
transceiver capacitancepin to GND--20pF
Resistance
[2]
Z
DRV
Z
INP
driver output impedancesteady-state drive28-44Ω
input impedance10--MΩ
Termination
V
TERM
[3]
termination voltage for
upstream port pull-up (R
PU
)
3.0
[4]
-3.6V
[1] D+ is the USB positive data pin (DPn); D− is the USB negative data pin (DMn).
[2] Includes external resistors of 20 Ω±1% on both D+ and D−.
[3] This voltage is available at pin V
[4] In ‘suspend’ mode the minimum voltage is 2.7 V.
reg(3.3)
.
15. Dynamic characteristics
Table 30: Dynamic characteristics
VCC= 4.0 to 5.5 V; V
SymbolParameterConditionsMinTypMaxUnit
Reset
t
W(RESET)
pulse width on input RESETcrystal oscillator running10--µs
Crystal oscillator
f
XTAL
[1] Dependent on the crystal oscillator start-up time.
The dynamic characteristics of the analog I/O ports (D+ and D−) as listed in Table 32
and Table 33, were determined using the circuit shown in Figure 22.
t
LOW
t
r
t
HD;STA
t
HIGH
D.U.T.
t
f
20 Ω
t
SU;DAT
test point
15 kΩ
t
SU;STA
C
t
HD;STA
P
t
SU;STO
MGR779
V
reg(3.3)
R
PU
S1
L
1.5 kΩ
test
D−/LS
D+/LS
D−/FS
D+/FS
S1
closed
open
open
closed
MGR775
Load capacitance:
CL= 50 pF (full-speed mode)
CL= 200 pF or 600 pF (low-speed mode, minimum or maximum timing).
Speed selection:
full-speed mode (FS): 1.5 kΩ pull-up resistor on D+
low-speed mode (LS): 1.5 kΩ pull-up resistor on D−.
This text gives a very brief insight to a complex technology. A more in-depth account
of soldering ICs can be found in our
Packages
There is no soldering method that is ideal for all IC packages. Wavesoldering is often
preferred when through-hole and surface mount components are mixed on one
printed-circuit board. Wave soldering can still be used for certain surface mount ICs,
but it is not suitable for fine pitch SMDs. In these situations reflow soldering is
recommended.
18.2 Surface mount packages
18.2.1 Reflow soldering
Reflow soldering requires solder paste (a suspension of fine solder particles, flux and
binding agent) to be applied to the printed-circuit board by screen printing, stencilling
or pressure-syringe dispensing before package placement.
ISP1122A
USB stand-alone hub
Data Handbook IC26; Integrated Circuit
(document order number 9398 652 90011).
Several methods exist for reflowing; for example, convection or convection/infrared
heating in a conveyor type oven. Throughput times (preheating, soldering and
cooling) vary between 100 and 200 seconds depending on heating method.
Typical reflow peak temperatures range from 215 to 250 °C. The top-surface
temperature of the packages should preferable be kept below 220 °C for thick/large
packages, and below 235 °C for small/thin packages.
18.2.2 Wave soldering
Conventional single wave soldering is not recommended for surface mount devices
(SMDs) or printed-circuit boards with a high component density, as solder bridging
and non-wetting can present major problems.
To overcome these problems the double-wave soldering method was specifically
developed.
If wave soldering is used the following conditions must be observed for optimal
results:
Use a double-wave soldering method comprising a turbulent wave with high
•
upward pressure followed by a smooth laminar wave.
For packages with leads on two sides and a pitch (e):
•
– larger than or equal to 1.27 mm, the footprint longitudinal axis is preferred to be
parallel to the transport direction of the printed-circuit board;
– smaller than 1.27 mm, the footprint longitudinal axis must be parallel to the
transport direction of the printed-circuit board.
The footprint must incorporate solder thieves at the downstream end.
During placement and before soldering, the package must be fixed with a droplet of
adhesive. The adhesive can be applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the adhesive is cured.
Typical dwell time is 4 seconds at 250 °C. A mildly-activated flux will eliminate the
need for removal of corrosive residues in most applications.
18.2.3 Manual soldering
Fix the component by first soldering two diagonally-opposite end leads. Use a low
voltage (24 V or less) soldering iron applied to the flat part of the lead. Contact time
must be limited to 10 seconds at up to 300 °C.
When using a dedicated tool, all other leads can be soldered in one operation within
2 to 5 seconds between 270 and 320 °C.
ISP1122A
USB stand-alone hub
For packages with leads on four sides, the footprint must be placed at a 45° angle
to the transport direction of the printed-circuit board. The footprint must
incorporate solder thieves downstream and at the side corners.
18.3 Through-hole mount packages
18.3.1 Soldering by dipping or by solder wave
The maximum permissible temperature of the solder is 260 °C; solder at this
temperature must not be in contact with the joints for more than 5 seconds. The total
contact time of successive solder waves must not exceed 5 seconds.
The device may be mounted up to the seating plane, but the temperature of the
plastic body must not exceed the specified maximum storage temperature (T
If the printed-circuit board has been pre-heated, forced cooling may be necessary
immediately after soldering to keep the temperature within the permissible limit.
18.3.2 Manual soldering
Apply the soldering iron (24 V or less) to the lead(s) of the package, either below the
seating plane or not more than 2 mm aboveit. If the temperature of the soldering iron
bit is less than 300 °C it may remain in contact for up to 10 seconds. If the bit
temperature is between 300 and 400 °C, contact may be up to 5 seconds.
maximum temperature (with respect to time) and body size of the package, there is a risk that internal
or external package cracks may occur due to vaporization of the moisture in them (the so called
popcorn effect). For details, refer to the Drypack information in the
Circuit Packages; Section: Packing Methods
printed-circuit board.
side, the solder cannot penetrate between the printed-circuit board and the heatsink. On versions with
the heatsink on the top side, the solder might be deposited on the heatsink surface.
direction. The package footprint must incorporate solder thieves downstream and at the side corners.
than 0.8 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.
0.65 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm.
ACPI — is an open industry specification for PC power management, co-developed by Intel Corp., Microsoft Corp. and
Toshiba
GoodLink — is a trademark of Koninklijke Philips Electronics N.V.
OnNow — is a trademark of Microsoft Corp.
SMBus — is a bus specification for PC power management, developed by Intel Corp. based on the I
Koninklijke Philips Electronics
SoftConnect — is a trademark of Koninklijke Philips Electronics
Objective dataDevelopmentThis data sheet contains data from theobjective specification for product development.Philips Semiconductors
Preliminary dataQualificationThis data sheet contains data from the preliminary specification. Supplementary data will be published at a
Product dataProductionThis data sheet contains data from the product specification. Philips Semiconductors reserves the right to
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at
URL http://www.semiconductors.philips.com.
[1]
Product status
[2]
Definition
reserves the right to change the specification in any manner without notice.
later date. Philips Semiconductors reserves the right to change the specification without notice, in order to
improve the design and supply the best possible product.
make changes at any time in order to improve the design, manufacturing and supply. Changes will be
communicated according to the Customer Product/Process Change Notification (CPCN) procedure
SNW-SQ-650A.
22. Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type
number and title. For detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System
(IEC 60134). Stress above one or more of the limiting values may cause permanent damage to the device. These are
stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics
sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes
only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified
use without further testing or modification.
23. Disclaimers
Life support — These products are not designed for use in life support appliances, devices, or systems where
malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers
using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips
Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products,
including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or
performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys
no licence or title under any patent, copyright, or mask work right to these products, and makes no representations or
warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise
specified.
24. Licenses
Purchase of Philips I2C components
2
Purchase of Philips I
under the Philips’ I
2
I
C system provided the system conforms to the I2C
specification defined by Philips. This specification can be
ordered using the code 9398 393 40011.
All rights are reserved. Reproduction in whole or in part is prohibited without the prior
written consent of the copyright owner.
The information presented in this document does not form part of any quotation or
contract, is believed to be accurate and reliable and may be changed without notice. No
liability will be accepted by the publisher for any consequence of its use. Publication
thereof does not convey nor imply any license under patent- or other industrial or
intellectual property rights.
Date of release: 30 October 2001Document order number: 9397 750 08958
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