IS31IO7325

IS31IO7325
MULTI-FUNCTION I/O DRIVER
January 2014
GENERAL DESCRIPTION
FEATURES
The IS31IO7325 2-wire serial-interfaced peripheral
features 16 I/O ports. Ports are divided into eight push
pull I/Os and eight open-drain I/Os and transition
detection.




Any of the 16 I/O ports can be configured as an input
or an output. All I/O ports configured as inputs are
continuously monitored for state changes (transition
detection). State changes are indicated by the INTB
output. The interrupt is latched, allowing detection of
transient changes. When the IS31IO7325 is
subsequently read through the serial interface, any
pending interrupt is cleared.
The open-drain outputs are rated to sink 20mA at
0.22V headroom, and are capable of driving LEDs.
The RSTB input clears the serial interface, terminating
any I2C communication to or from the IS31IO7325. The
IS31IO7325 uses two address inputs to allow 4 I2C
slave addresses. The slave address also determines
the power-up logic state for the I/O ports.




400kHz I2C serial interface
2.4V to 5.5V operation
8 push-pull I/O ports
8 open-drain I/O ports, rated to 20mA sink current
at 0.22V headroom
Selectable I/O port power-up default logic states
INTB output alerts change on inputs
Low 0.3μA (Typ.) standby current
-40°C ~ +125°C temperature range
APPLICATIONS






Cell phones
Notebooks
SAN/NAS
Satellite radio
Servers
Automotive
TYPICAL APPLICATION CIRCUIT
Figure 1
Typical Application Circuit
Note:
VBattery: 2.4V~5.5V, 2.8V is recommended.
VDD: 1.4V~5.5V, VDD ≤ VBattery, 2.8V is recommended.
VDD should be turned off when system power off because OD ports are open default.
VDD = VBattery is forbidden.
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Rev. C, 01/03/2014
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IS31IO7325
PIN CONFIGURATION
Package
QFN-24
Pin Configuration (Top View)
PP0 1
18 AD0
PP1 2
17 PP7
PP2 3
16 PP6
PP3 4
15 PP5
OD0 5
14 PP4
OD1 6
13 OD7
SOP-24
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IS31IO7325
PIN DESCRIPTION
No.
Pin
Description
1~4, 14~17
PP0~PP7
CMOS push-pull I/O ports.
5~8, 10~13
OD0~OD7
Open-drain I/O ports.
9
GND
Ground.
18
AD0
Address inputs. Select device slave address with AD0
and AD1.
19
SCL
I2C-compatible serial-clock input.
20
SDA
I2C-compatible serial-data I/O.
21
VCC
Positive supply voltage. Bypass VCC to GND with a
ceramic capacitor of at least 0.1μF.
22
INTB
Interrupt output, active low. This is an open-drain
output.
23
RSTB
Reset input, active low. Drive RSTB pin low to clear the
2-wire interface.
24
AD1
Address inputs. Select device slave address with AD0
and AD1.
Thermal Pad
Connect to GND.
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IS31IO7325
ORDERING INFORMATION
Industrial Range: -40°C to +125°C
Order Part No.
Package
QTY
IS31IO7325-QFLS4-TR
QFN-24, Lead-free
2500/Reel
IS31IO7325-GRLS4
SOP-24, Lead-free
30/Tube
Copyright © 2014 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances
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Rev. C, 01/03/2014
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IS31IO7325
ABSOLUTE MAXIMUM RATINGS
Supply voltage, VCC
SCL, SDA, AD, RSTB, INTB, OD0~OD7
PP0~PP7
PP source output current
PP/OD sink current
SDA sink current
INTB sink current
Maximum junction temperature, TJMAX
Storage temperature range, TSTG
Operating temperature range, TA
ESD (HBM)
ESD (CDM)
-0.3V ~ +6.0V
-0.3V ~ +6.0V
-0.3V ~ VCC+0.3V
±100mA
120mA
10mA
10mA
150°C
-65°C ~ +150°C
−40°C ~ +125°C
2kV
1kV
Note:
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only
and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is
not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
VCC = 2.4V ~ 5.5V, TA = -40°C ~ +125°C, unless otherwise noted. Typical values are VCC = 3.3V, TA = 25°C. (Note 1)
Symbol
Parameter
Condition
Min.
Typ.
Unit
5.5
V
VCC
Supply voltage
VPOR
Power-on-reset voltage
ISTB
Standby current
(Interface idle)
SCL and SDA and other digital inputs at
VCC
0.3
1.9
μA
I+
Supply current
(Interface running)
fSCL = 400kHz, other digital inputs at VCC
8
20
μA
VIH
Input high-voltage
SDA, SCL, AD0, AD1, RSTB,
OD0~OD7, PP0~PP7
VIL
Input low-voltage
SDA, SCL, AD0, AD1, RSTB,
OD0~OD7, PP0~PP7
Input leakage current
SDA, SCL, AD0, AD1, RSTB,
OD0~OD7, PP0~PP7 at VCC or GND
CIN
Input capacitance
SDA, SCL, AD0, AD1, RSTB,
OD0~OD7, PP0~PP7 (Note 3)
VOL
Output low voltage
PP0~PP7, OD0~OD7
IIH, IIL
VOH
Output high voltage
PP0~PP7
2.4
Max.
VCC falling, TA = -40°C
2.35
VCC falling, TA = -20°C
2.3
1.4
V
-0.2
0.4
V
+0.2
μA
10
pF
VCC = 2.5V, ISINK = 10mA
200
VCC = 3.3V, ISINK = 15mA
240
VCC = 5.0V, ISINK = 20mA
250
VCC = 2.5V, ISOURCE = 5mA
2.2
VCC = 3.3V, ISOURCE = 5mA
3.1
VCC = 5.0V, ISOURCE = 10mA
4.72
V
mV
V
VOLSDA
Output low-voltage SDA
ISINK = 6mA
180
mV
VOLINTB
Output low-voltage INTB
ISINK = 5mA
180
mV
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IS31IO7325
TIMING CHARACTERISTICS
VCC = 2.4V ~ 5.5V, TA = -40°C ~ +125°C, unless otherwise noted. Typical values are VCC = 3.3V, TA = 25°C. (Note 3)
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
400
kHz
fSCL
Serial-clock frequency
tBUF
Bus free time between a STOP and a
START condition
1.3
μs
tHD, STA
Hold time (repeated) START condition
0.6
μs
tSU, STA
Repeated START condition setup time
0.6
μs
tSU, STO
STOP condition setup time
0.6
μs
tHD, DAT
Data hold time
tSU, DAT
Data setup time
100
ns
tLOW
SCL clock low period
1.3
μs
tHIGH
SCL clock high period
0.7
μs
0.9
(Note 2)
μs
tR
Rise time of both SDA and SCL signals,
receiving
(Note 4)
20 + 0.1Cb
300
ns
tF
Fall time of both SDA and SCL signals,
receiving
(Note 4)
20 + 0.1Cb
300
ns
Fall time of SDA transmitting
(Note 4)
20 + 0.1Cb
250
ns
tSP
Pulse width of spike suppressed
(Note 5)
50
Cb
Capacitive load for each bus line
tW
RSTB pulse width
tF, TX
tRSTB
ns
400
RSTB rising to START condition setup
time
pF
500
ns
1
μs
Port and Interrupt INTB Timing Characteristic
VCC = 2.4V ~ 5.5V, TA = -40°C ~ +125°C, unless otherwise noted. Typical values are VCC = 3.3V, TA = 25°C. (Note 3)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Unit
Port output data valid
tPV
CL≤ 100pF
4
μs
Port input setup time
tPSU
CL≤ 100pF
0
μs
Port input hold time
tPH
CL≤ 100pF
4
μs
INTB input data valid time
tIV
CL≤ 100pF
4
μs
INTB reset delay time from acknowledge
tIR
CL≤ 100pF
4
μs
Note 1: All parameters are tested at TA = 25°C. Specifications over temperature are guaranteed by design.
Note 2: A master device must provide a hold time of at least 300ns for the SDA signal (referred to VIL of the SCL signal) in order to bridge the
undefined region of SCL’s falling edge.
Note 3: Guaranteed by design.
Note 4: Cb = total capacitance of one bus line in pF. ISINK ≤ 6mA. tR and tF measured between 0.3 × VCC and 0.7 × VCC.
Note 5: Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.
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IS31IO7325
Table 1 Power Up Default State for I/O Ports
Pin
Connection
Port Power Up Default
AD1
AD0
PP7 PP6 PP5 PP4 PP3 PP2 PP1 PP0 OD7
OD6
OD5
OD4
OD3
OD2
OD1
OD0
GND
GND
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
GND
VCC
0
0
0
0
1
1
1
1
0
0
0
0
Hi-Z
Hi-Z
Hi-Z
Hi-Z
VCC
GND
1
1
1
1
0
0
0
0
Hi-Z
Hi-Z
Hi-Z
Hi-Z
0
0
0
0
VCC
VCC
1
1
1
1
1
1
1
1
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Table 2 Command Byte Register
Command Byte Address(Hex)
Function
Power Up Default
Protocol
00
Input port A (OD0~OD7)
XXXX XXXX
R
01
Input port B (PP0~PP7)
XXXX XXXX
R
02
Output port A
Refer to Table 1
R/W
03
Output port B
Refer to Table 1
R/W
04
Port A configuration
0000 0000
R/W
05
Port B configuration
0000 0000
R/W
06
Port A interrupt control
0000 0000
R/W
07
Port B interrupt control
0000 0000
R/W
Figure 2 2-Wire Serial Interface Timing Details
Figure 3 START and STOP Conditions
Figure 4 Bit Transfer
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IS31IO7325
FUNCTIONAL BLOCK DIAGRAM
VCC
Power-on
Reset
RSTB
AD0
AD1
SCL
SDA
Input
Filter
I2C
Control
I/O
Ports
OD0~OD7
PP0~PP7
INTB
GND
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IS31IO7325
APPLICATION INFORMATION
FUNCTIONAL OVERVIEW
The IS31IO7325 is a Multi-function I/O driver operating
from a 2.4V to 5.5V supply with eight push-pull and
eight open-drain I/O ports. Each open-drain and
push-pull port is rated to sink 20mA at 0.22V
headroom, and the entire device is rated to sink
320mA at 0.22V headroom into all ports combined.
The outputs drive loads connected to supplies up to
+5.5V.
The IS31IO7325 is set to four I2C slave addresses
using the address select inputs AD0 and AD1, and is
accessed over an I2C serial interface up to 400kHz.
The RSTB input clears the serial interface in case of a
bus lockup, terminating any serial transaction to or
from the IS31IO7325.
The IS31IO7325 consists of input, output port registers,
configuration registers and interrupt control register. All
I/O ports offer latching transition detection when
configured as inputs. All input ports are continuously
monitored for changes.
A latching interrupt output, INTB, is programmed to
flag logic changes on ports used as inputs. Data
changes on any input port forces INTB to a logic-low.
Changing the I/O port level through the serial interface
does not cause an interrupt. The interrupt output INTB
is cleared successfully by reading the corresponding
input/output ports.
Ports default to logic-high or logic-low on power-up in
groups of four (see Table 1).
INITIAL POWER-UP
On power-up, the transition detection logic is reset,
and INTB is reset. The power-up default states of the
16 I/O ports are set according to the I2C slave address
selection inputs, AD0 and AD1 (see Table 1). For I/O
ports used as inputs, ensure that the default states are
logic-high so that the I/O ports power up in the high
impedance state.
POWER-ON RESET
The IS31IO7325 contains an integral power-on-reset
(POR) circuit that ensures all registers are reset to a
known state on power-up. When VCC rises above VPOR
(2.3V max), the POR circuit releases the registers and
2-wire interface for normal operation. When VCC drops
to less than VPOR, the IS31IO7325 resets all register
contents to the POR defaults.
RSTB Input
The active-low RSTB input voids any I2C transaction
involving the IS31IO7325, forcing the IS31IO7325 into
the I2C STOP condition. A reset does not affect the
interrupt output.
STANDBY MODE
automatically enters standby mode, drawing minimal
supply current.
I/O PORT INPUT TRANSITION DETECTION
All I/O ports configured as inputs are monitored for
changes since the expander was last accessed
through the serial interface. The open-drain interrupt
output, INTB, activates when one of the port pins
changes states and only when the pin is configured as
an input. The interrupt deactivates when the
input/output register is read. A pin configured as an
output does not cause an interrupt. Each 8-bit port
register is read independently; therefore, an interrupt
caused by port A (OD0~OD7) is not cleared by a read
of port B (PP0~PP7)’s register.
Changing an I/O from an output to an input may cause
a false interrupt to occur if the state of that I/O does not
match the content of output port register. The
IS31IO7325 has interrupt control register to avoid false
interrupt by setting the interrupt control register bit high
firstly, when the I/O state is stable, clear the interrupt
control register to enable the input transition detection
function.
ACCESSING THE IS31IO7325
Serial Addressing
The IS31IO7325 operates as a slave that sends and
receives data through a 2-wire interface. The interface
uses a serial data line (SDA) and a serial clock line
(SCL) to achieve bidirectional communication between
master(s) and slave(s). A master, typically a
microcontroller, initiates all data transfers to and from
the IS31IO7325, and generates the SCL clock that
synchronizes the data transfer (see Figure 2).
SDA operates as both an input and an open-drain
output. A pull up resistor, typically 4.7kΩ, is required on
SDA. SCL operates only as an input. A pull up resistor,
typically 4.7kΩ, is required on SCL if there are multiple
masters on the 2-wire interface, or if the master in a
single-master system has an open-drain SCL output.
Each transmission consists of a START condition sent
by a master, followed by the IS31IO7325’s 7-bit slave
addresses plus R/W bits, 1 or more data bytes, and
finally a STOP condition (see Figure 3).
START and STOP Conditions
Both SCL and SDA remain high when the interface is
not busy. A master signals the beginning of a
transmission with a START (S) condition by
transitioning SDA from high to low while SCL is high.
When the master has finished communicating with the
slave, the master issues a STOP (P) condition by
transitioning SDA from low to high while SCL is high.
The bus is then free for another transmission (see
Figure 3)
When the serial interface is idle, the IS31IO7325
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IS31IO7325
Bit Transfer
One data bit is transferred during each clock pulse.
The data on SDA must remain stable while SCL is high
(Figure 4).
Figure 5 Acknowledge
Figure 6
Writing to the IS31IO7325
Reading I/O Ports of IS31IO7325
Figure 7
Slave Address
The IS31IO7325 has a 7-bit slave address. The 8th bit
____
following the 7-bit slave address is the R/W bit. Set
this bit low for a write command and high for a read
command.
The complete slave address is:
A6:A2
A1
A0
R/W
10110
AD1
AD0
0/1
Data Bus Transaction
The command byte is the first byte to follow the 8-bit
device slave address during a write transmission (see
Table 2). The command byte is used to determine
which of the following registers are written or read.
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Acknowledge
The acknowledge bit is a clocked 9th bit the recipient
uses to acknowledge receipt of each byte of data (see
Figure 5). Each byte transferred effectively requires
9bits. The master generates the 9th clock pulse, and
the recipient pulls down SDA during the acknowledge
clock pulse, such that the SDA line is stable low during
the high period of the clock pulse. When the master is
transmitting to the IS31IO7325, the device generates
the acknowledge bit because the IS31IO7325 is the
recipient. When the IS31IO7325 is transmitting to the
master, the master generates the acknowledge bit
because the master is the recipient.
10
IS31IO7325
Configuration Registers
Port Output Signal-Level Translation
The configuration registers configure the directions of
the I/O pins. Set the bit in the respective configuration
register to enable the corresponding port as an input.
Clear the bit in the configuration register to enable the
corresponding port as an output.
The open-drain output architecture allows for level
translation to higher or lower voltages than the
IS31IO7325’s supply. Each of the push-pull output
ports has protection diodes to V+ and GND. When a
port output is driven to a voltage higher than V+ or
lower than GND, the appropriate protection diode
clamps the output to a diode drop above V+ or below
GND. When the IS31IO7325 is powered down (V+ =
0V), every output port’s protection diodes to V+ and
GND continue to appear as a diode clamp from each
output to GND (Figure 8). Each of the I/O ports
OD0~OD7 has a protection diode to GND (Figure 9).
When a port is driven to a voltage lower than GND, the
protection diode clamps the port to a diode drop below
GND. To obtain a high voltage, Open-drain I/O Ports
should connect a resistance to VCC (Figure 9).
Interrupt Control Registers
The interrupt control registers control the interrupt
function of I/O ports when the I/O port used as input.
Set the bit in the respective interrupt control register to
disable the corresponding port’s interrupt function.
Clear the bit in the interrupt control register to enable
the corresponding port’s interrupt function.
Writing to Port Registers
Transmit data to the IS31IO7325 by sending the
device slave address and setting the LSB to a logic
zero. The command byte is sent after the address and
determines which registers receive the data following
the command byte.
A write to either output port groups of the IS31IO7325
starts with the master transmitting the group’s slave
____
address with the R/W bit set low. The master can now
transmit the command byte and data byte.
In the case of LED load at OD outputs, the voltage at
OD is between VCC and GND when OD is intended
high to turn off the LED, causing ICC leakage current. A
100K pull-up resistor will force OD high at VCC and
eliminate the leakage current. PP outputs can be set
high at VCC with LED load, resulting in no leakage
current without any pull-up resistor.
Reading Port Registers
To read the device data, the bus master must first send
____
the IS31IO7325 address with the R/W bit set to zero,
followed by the command byte, which determines
which register is accessed. After a restart, the bus
master must then send the IS31IO7325 address with
____
the R/W bit set to 1. Data from the register defined by
the command byte is then sent from the IS31IO7325 to
the master.
The IS31IO7325 acknowledges the slave address, and
samples the ports during the acknowledge bit. INTB
desserts during the slave address acknowledge. When
the master reads one byte from the I/O ports of the
IS31IO7325 and subsequently issues a STOP
condition (Figure 7), the IS31IO7325 transmits the
current port data, clears the change flags, and resets
the transition detection. INTB desserts during the slave
acknowledge. The new snapshot data is the current
port data transmitted to the master, and therefore, port
changes occurring during the transmission are
detected.
Figure 8
Figure 9
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IS31IO7325 Push-Pull I/O Ports Structure
IS31IO7325 Open-Drain I/O Ports Structure
11
IS31IO7325
CLASSIFICATION REFLOW PROFILES
Profile Feature
Pb-Free Assembly
Preheat & Soak
Temperature min (Tsmin)
Temperature max (Tsmax)
Time (Tsmin to Tsmax) (ts)
150°C
200°C
60-120 seconds
Average ramp-up rate (Tsmax to Tp)
3°C/second max.
Liquidous temperature (TL)
Time at liquidous (tL)
217°C
60-150 seconds
Peak package body temperature (Tp)*
Max 260°C
Time (tp)** within 5°C of the specified
classification temperature (Tc)
Max 30 seconds
Average ramp-down rate (Tp to Tsmax)
6°C/second max.
Time 25°C to peak temperature
8 minutes max.
Figure 10
Classification Profile
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IS31IO7325
PACKAGE INFORMATION
QFN-24
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Rev. C, 01/03/2014
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IS31IO7325
SOP-24
Note: All dimensions in millimeters unless otherwise stated.
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