Data Sheet

PCAL6408A
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
with interrupt output, reset, and configuration registers
Rev. 3 — 18 September 2013
Product data sheet
1. General description
The PCAL6408A is an 8-bit general-purpose I/O expander that provides remote I/O
expansion for most microcontroller families via the I2C-bus interface.
NXP I/O expanders provide a simple solution when additional I/Os are needed while
keeping interconnections to a minimum, for example, in battery-powered mobile
applications for interfacing to sensors, push buttons, keypad, etc. In addition to providing
a flexible set of GPIOs, it simplifies interconnection of a processor running at one voltage
level to I/O devices operating at a different (usually higher) voltage level. The PCAL6408A
has built-in level shifting feature that makes these devices extremely flexible in mixed
signal environments where communication between incompatible I/O voltages is required.
Its wide VDD range of 1.65 V to 5.5 V on the dual power rail allows seamless
communications with next-generation low voltage microprocessors and microcontrollers
on the interface side (SDA/SCL) and peripherals at a higher voltage on the port side.
There are two supply voltages for PCAL6408A: VDD(I2C-bus) and VDD(P). VDD(I2C-bus)
provides the supply voltage for the interface at the master side (for example, a
microcontroller) and the VDD(P) provides the supply for core circuits and Port P. The
bidirectional voltage level translation in the PCAL6408A is provided through VDD(I2C-bus).
VDD(I2C-bus) should be connected to the VDD of the external SCL/SDA lines. This indicates
the VDD level of the I2C-bus to the PCAL6408A, while the voltage level on Port P of the
PCAL6408A is determined by the VDD(P).
The PCAL6408A contains the PCA6408A register set of 8-bit Configuration, Input, Output,
and Polarity Inversion registers and additionally, the PCAL6408A has Agile I/O, which are
additional features specifically designed to enhance the I/O. These additional features
are: programmable output drive strength, latchable inputs, programmable
pull-up/pull-down resistors, maskable interrupt, interrupt status register, programmable
open-drain or push-pull outputs. The PCAL6408A is a pin-to-pin replacement to the
PCA6408A, however, the PCAL6408A powers up with all I/O interrupts masked. This
mask default allows for a board bring-up free of spurious interrupts at power-up.
At power-on, the I/Os are configured as inputs. However, the system master can enable
the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for
each input or output is kept in the corresponding input or output register. The polarity of
the Input Port register can be inverted with the Polarity Inversion register, saving external
logic gates. Programmable pull-up and pull-down resistors eliminate the need for discrete
components.
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
The system master can reset the PCAL6408A in the event of a time-out or other improper
operation by asserting a LOW in the RESET input. The power-on reset puts the registers
in their default state and initializes the I2C-bus/SMBus state machine. The RESET pin
causes the same reset/initialization to occur without de-powering the part.
The PCAL6408A open-drain interrupt (INT) output is activated when any input state differs
from its corresponding Input Port register state and is used to indicate to the system
master that an input state has changed.
INT can be connected to the interrupt input of a microcontroller. By sending an interrupt
signal on this line, the remote I/O can inform the microcontroller if there is incoming data
on its ports without having to communicate via the I2C-bus. Thus, the PCAL6408A can
remain a simple slave device. The input latch feature holds or latches the input pin state
and keeps the logic values that created the interrupt until the master can service the
interrupt. This minimizes the host’s interrupt service response for fast moving inputs.
The device Port P outputs have 25 mA sink capabilities for directly driving LEDs while
consuming low device current.
One hardware pin (ADDR) can be used to program and vary the fixed I2C-bus address
and allow up to two devices to share the same I2C-bus or SMBus.
2. Features and benefits
 I2C-bus to parallel port expander
 Operating power supply voltage range of 1.65 V to 5.5 V
 Allows bidirectional voltage-level translation and GPIO expansion between:
 1.8 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V or 5 V Port P
 2.5 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V or 5 V Port P
 3.3 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V or 5 V Port P
 5 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V or 5 V Port P
 Low standby current consumption of 1 A
 Schmitt-trigger action allows slow input transition and better switching noise immunity
at the SCL and SDA inputs
 Vhys = 0.18 V (typical) at 1.8 V
 Vhys = 0.25 V (typical) at 2.5 V
 Vhys = 0.33 V (typical) at 3.3 V
 Vhys = 0.5 V (typical) at 5 V
 5 V tolerant I/O ports
 Active LOW reset input (RESET)
 Open-drain active LOW interrupt output (INT)
 400 kHz Fast-mode I2C-bus
 Internal power-on reset
 Power-up with all channels configured as inputs
 No glitch on power-up
 Noise filter on SCL/SDA inputs
 Latched outputs with 25 mA drive maximum capability for directly driving LEDs
 Latch-up performance exceeds 100 mA per JESD 78, Class II
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
2 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
 ESD protection exceeds JESD 22
 2000 V Human-Body Model (A114-A)
 1000 V Charged-Device Model (C101)
 Packages offered: HVQFN16, TSSOP16, XQFN16,
XFBGA16 (1.6 mm  1.6 mm  0.5 mm)
2.1 Agile I/O features





Software backward compatible with PCA6408A with interrupts disabled at power-up
Pin-to-pin drop-in replacement for PCA6408A
Output port configuration: bank selectable push-pull or open-drain output stages
Interrupt status: read-only register identifies the source of an interrupt
Bit-wise I/O programming features:
 Output drive strength: four programmable drive strengths to reduce rise and fall
times in low-capacitance applications
 Input latch: Input Port register values changes are kept until the Input Port register
is read
 Pull-up/pull-down enable: floating input or pull-up/pull-down resistor enable
 Pull-up/pull-down selection: 100 k pull-up/pull-down resistor selection
 Interrupt mask: mask prevents the generation of the interrupt when input changes
state to prevent spurious interrupts
3. Ordering information
Table 1.
Ordering information
Type number
Topside
marking
Package
Name
Description
Version
PCAL6408ABS
L8A
HVQFN16
plastic thermal enhanced very thin quad flat package; no leads;
16 terminals; body 3  3  0.85 mm
SOT758-1
PCAL6408APW PL6408A
TSSOP16
plastic thin shrink small outline package; 16 leads;
body width 4.4 mm
SOT403-1
PCAL6408AHK
L8
XQFN16
plastic, extremely thin quad flat package; no leads; 16 terminals;
body 1.80  2.60  0.50 mm
SOT1161-1
PCAL6408AEX
L8
XFBGA16
plastic, extremely thin fine-pitch ball grid array package; 16 balls; SOT1354-1
body 1.6  1.6  0.5 mm
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
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3 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
3.1 Ordering options
Table 2.
Ordering options
Type number
Orderable
part number
Package
Packing method
Minimum
order quantity
Temperature
PCAL6408ABS
PCAL6408ABSHP
HVQFN16
Reel 13” Q2/T3
*standard mark SMD
6000
Tamb = 40 C to +85 C
PCAL6408APW
PCAL6408APWJ
TSSOP16
Reel 13” Q1/T1
*standard mark SMD
2500
Tamb = 40 C to +85 C
PCAL6408AHK
PCAL6408AHKX
XQFN16
Reel 7” Q1/T1
*standard mark SMD
4000
Tamb = 40 C to +85 C
PCAL6408AEX
PCAL6408AEXX
XFBGA16
Reel 7” Q1/T1
*standard mark SMD
5000
Tamb = 40 C to +85 C
4. Block diagram
PCAL6408A
INT
INTERRUPT
LOGIC
LP FILTER
ADDR
SCL
SDA
INPUT
FILTER
I2C-BUS
CONTROL
VDD(I2C-bus)
VDD(P)
RESET
POWER-ON
RESET
SHIFT
REGISTER
8 BITS
I/O
PORT
P0 to P7
write pulse
read pulse
I/O control
VSS
002aah085
All I/Os are set to inputs at reset.
Fig 1.
PCAL6408A
Product data sheet
Block diagram (positive logic)
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© NXP B.V. 2013. All rights reserved.
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
5. Pinning information
13 SDA
2
15 SDA
P0
3
14 SCL
P1
3
10 P7
P0
4
13 INT
P1
5
P2
4
9
P2
6
11 P6
8
P3
7
10 P5
P5
11 INT
ADDR
RESET
7
2
12 SCL
P4
1
6
RESET
VSS
8
VSS
16 VDD(P)
5
1
P3
VDD(I2C-bus)
14 VDD(P)
terminal 1
index area
15 VDD(I2C-bus)
16 ADDR
5.1 Pinning
PCAL6408APW
PCAL6408ABS
12 P7
9
P4
P6
002aah087
Transparent top view
002aah086
The exposed center pad, if used, must be
connected only as a secondary VSS or
must be left electrically open.
Fig 2.
Pin configuration for TSSOP16
Fig 3.
Pin configuration for HVQFN16
13 SDA
14 VDD(P)
15 VDD(I2C-bus)
terminal 1
index area
16 ADDR
PCAL6408AHK
RESET 1
12 SCL
P2 4
9 P6
P5 8
10 P7
P4 7
P1 3
VSS 6
11 INT
P3 5
P0 2
002aah088
Transparent top view
Fig 4.
PCAL6408A
Product data sheet
Pin configuration for XQFN16
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
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Fig 5.
3
DDK
Pin configuration for
1.6 mm  1.6 mm XFBGA16
Fig 6.
Ball mapping for
1.6 mm  1.6 mm XFBGA16
5.2 Pin description
Table 3.
Symbol
Pin description
Pin
Description
TSSOP16
HVQFN16
XQFN16
XFBGA16
VDD(I2C-bus)
1
15
15
A2
Supply voltage of I2C-bus. Connect directly to the VDD of
the external I2C master. Provides voltage-level
translation.
ADDR
2
16
16
B2
Address input. Connect directly to VDD(P) or ground.
RESET
3
1
1
A1
Active LOW reset input. Connect to VDD(I2C-bus) through a
pull-up resistor if no active connection is used.
P0[1]
4
2
2
B1
Port P input/output 0.
P1[1]
5
3
3
C2
Port P input/output 1.
P2[1]
6
4
4
C1
Port P input/output 2.
P3[1]
7
5
5
D1
Port P input/output 3.
VSS
8
6
6
D2
Ground.
P4[1]
9
7
7
D3
Port P input/output 4.
P5[1]
10
8
8
D5
Port P input/output 5.
P6[1]
11
9
9
C4
Port P input/output 6.
P7[1]
12
10
10
C3
Port P input/output 7.
INT
13
11
11
B4
Interrupt output. Connect to VDD(I2C-bus) through a pull-up
resistor.
SCL
14
12
12
A4
Serial clock bus. Connect to VDD(I2C-bus) through a pull-up
resistor.
SDA
15
13
13
B3
Serial data bus. Connect to VDD(I2C-bus) through a pull-up
resistor.
VDD(P)
16
14
14
A3
Supply voltage of PCAL6408A for Port P.
[1]
All I/O are configured as input at power-on.
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
6. Voltage translation
Table 4 shows how to set up VDD levels for the necessary voltage translation between the
I2C-bus and the PCAL6408A.
Table 4.
Voltage translation
VDD(I2C-bus) (SDA and SCL of I2C master)
VDD(P) (Port P)
1.8 V
1.8 V
1.8 V
2.5 V
1.8 V
3.3 V
1.8 V
5V
2.5 V
1.8 V
2.5 V
2.5 V
2.5 V
3.3 V
2.5 V
5V
3.3 V
1.8 V
3.3 V
2.5 V
3.3 V
3.3 V
3.3 V
5V
5V
1.8 V
5V
2.5 V
5V
3.3 V
5V
5V
7. Functional description
Refer to Figure 1 “Block diagram (positive logic)”.
7.1 Device address
The address of the PCAL6408A is shown in Figure 7.
slave address
0
1
0
0
0
0
fixed
AD
R/W
DR
programmable
002aaf539
Fig 7.
PCAL6408A address
ADDR is the hardware address package pin and is held to either HIGH (logic 1) or LOW
(logic 0) to assign one of the two possible slave addresses. The last bit of the slave
address defines the operation (read or write) to be performed. A HIGH (logic 1) selects a
read operation, while a LOW (logic 0) selects a write operation.
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
7.2 Interface definition
Table 5.
Interface definition
Byte
I2C-bus
Bit
slave address
I/O data bus
7 (MSB)
6
5
4
3
2
1
0 (LSB)
L
H
L
L
L
L
ADDR
R/W
P7
P6
P5
P4
P3
P2
P1
P0
7.3 Pointer register and command byte
Following the successful acknowledgement of the address byte, the bus master sends a
command byte, which is stored in the Pointer register in the PCAL6408A. 2 bits of this
data byte state the operation (read or write) and the internal registers (Input, Output,
Polarity Inversion, or Configuration) that are affected. Bit 6 in conjunction with the lower
3 bits of the Command byte are used to point to the extended features of the device
(Agile I/O). This register is ‘write only’.
B7
B6
B5
B4
B3
B2
B1
B0
002aaf540
Fig 8.
Table 6.
Pointer register bits
Command byte
Pointer register bits
Command byte Register
Protocol
Power-up
default
read byte
xxxx xxxx[1]
B7
B6
B5
B4
B3
B2
B1
B0
0
0
0
0
0
0
0
0
00h
Input port
0
0
0
0
0
0
0
1
01h
Output port
read/write byte
1111 1111
0
0
0
0
0
0
1
0
02h
Polarity Inversion
read/write byte
0000 0000
0
0
0
0
0
0
1
1
03h
Configuration
read/write byte
1111 1111
0
1
0
0
0
0
0
0
40h
Output drive strength 0
read/write byte
1111 1111
0
1
0
0
0
0
0
1
41h
Output drive strength 1
read/write byte
1111 1111
0
1
0
0
0
0
1
0
42h
Input latch
read/write byte
0000 0000
0
1
0
0
0
0
1
1
43h
Pull-up/pull-down enable
read/write byte
0000 0000
0
1
0
0
0
1
0
0
44h
Pull-up/pull-down selection read/write byte
1111 1111
0
1
0
0
0
1
0
1
45h
Interrupt mask
read/write byte
1111 1111
0
1
0
0
0
1
1
0
46h
Interrupt status
read byte
0000 0000
0
1
0
0
1
1
1
1
4Fh
Output port configuration
read/write byte
0000 0000
[1]
Undefined.
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
7.4 Register descriptions
7.4.1 Input port register (00h)
The Input port register (register 0) reflects the incoming logic levels of the pins, regardless
of whether the pin is defined as an input or an output by the Configuration register. The
Input port register is read only; writes to this register have no effect. The default value ‘X’
is determined by the externally applied logic level. An Input port register read operation is
performed as described in Section 8.2 “Read commands”.
Table 7.
Input port register (address 00h)
Bit
7
6
5
4
3
2
1
0
Symbol
I7
I6
I5
I4
I3
I2
I1
I0
Default
X
X
X
X
X
X
X
X
7.4.2 Output port register (01h)
The Output port register (register 1) shows the outgoing logic levels of the pins defined as
outputs by the Configuration register. Bit values in these registers have no effect on pins
defined as inputs. In turn, reads from this register reflect the value that was written to this
register, not the actual pin value.
Table 8.
Bit
Output port register (address 01h)
7
6
5
4
3
2
1
0
Symbol
O7
O6
O5
O4
O3
O2
O1
O0
Default
1
1
1
1
1
1
1
1
7.4.3 Polarity inversion register (02h)
The Polarity inversion register (register 2) allows polarity inversion of pins defined as
inputs by the Configuration register. If a bit in this register is set (written with ‘1’), the
corresponding port pin’s polarity is inverted. If a bit in this register is cleared (written with a
‘0’), the corresponding port pin’s original polarity is retained.
Table 9.
Bit
Polarity inversion register (address 02h)
7
6
5
4
3
2
1
0
Symbol
N7
N6
N5
N4
N3
N2
N1
N0
Default
0
0
0
0
0
0
0
0
7.4.4 Configuration register (03h)
The Configuration register (register 3) configures the direction of the I/O pins. If a bit in this
register is set to 1, the corresponding port pin is enabled as a high-impedance input. If a
bit in this register is cleared to 0, the corresponding port pin is enabled as an output.
Table 10.
Bit
PCAL6408A
Product data sheet
Configuration register (address 03h)
7
6
5
4
3
2
1
0
Symbol
C7
C6
C5
C4
C3
C2
C1
C0
Default
1
1
1
1
1
1
1
1
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
7.4.5 Output drive strength registers (40h, 41h)
The Output drive strength registers control the output drive level of the GPIO. Each GPIO
can be configured independently to a certain output current level by two register control
bits. For example, Port 7 is controlled by register 41 CC7 (bits [7:6]), Port 6 is controlled
by register 41 CC6 (bits [5:4]). The output drive level of the GPIO is programmed
00b = 0.25, 01b = 0.5, 10b = 0.75 or 11b = 1 of the drive capability of the I/O.
See Section 9.2 “Output drive strength control” for more details.
Table 11.
Bit
Current control register (address 40h)
7
Symbol
Default
Table 12.
Bit
5
CC3
1
4
3
CC2
1
1
2
1
CC1
1
0
CC0
1
1
1
1
3
2
1
0
Current control register (address 41h)
7
Symbol
Default
6
6
5
CC7
1
4
CC6
1
1
CC5
1
1
CC4
1
1
1
7.4.6 Input latch register (42h)
The Input latch register enables and disables the input latch of the I/O pins. These
registers are effective only when the pin is configured as an input port. When an input
latch register bit is 0, the corresponding input pin state is not latched. A state change in
the corresponding input pin generates an interrupt. A read of the input port register clears
the interrupt. If the input goes back to its initial logic state before the input port register is
read, then the interrupt is cleared. See Figure 13.
When an input latch register bit is 1, the corresponding input pin state is latched. A change
of state of the input generates an interrupt and the input logic value is loaded into the
corresponding bit of the input port register (registers 0). A read of the input port register
clears the interrupt. If the input pin returns to its initial logic state before the input port
register is read, then the interrupt is not cleared and the corresponding bit of the input port
register keeps the logic value that initiated the interrupt. See Figure 14. For example, if the
P4 input was as logic 0 and the input goes to logic 1 then back to logic 0, the input port
register captures this change and an interrupt is generated (if unmasked). When the read
is performed on the input port register, the interrupt is cleared, assuming there were no
additional input(s) that have changed, and bit 4 of the input port register reads ‘1’. The
next read of the input port register bit 4 should now read ‘0’.
An interrupt remains active when a non-latched input simultaneously switches state with a
latched input and then returns to its original state. A read of the input port register reflects
only the change of state of the latched input and also clears the interrupt. The interrupt is
not cleared if the input latch register changes from latched to non-latched configuration.
If the input pin is changed from latched to non-latched input, a read from the input port
register reflects the current port logic level. If the input pin is changed from non-latched to
latched input, the read from the input port register reflects the latched logic level.
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Table 13.
Input latch register (address 42h)
Bit
7
6
5
4
3
2
1
0
Symbol
L7
L6
L5
L4
L3
L2
L1
L0
Default
0
0
0
0
0
0
0
0
7.4.7 Pull-up/pull-down enable register (43h)
This register allows the user to enable or disable pull-up/pull-down resistors on the I/O
pins. Setting the bit to logic 1 enables the selection of pull-up/pull-down resistors. Setting
the bit to logic 0 disconnects the pull-up/pull-down resistors from the I/O pins. Also, the
resistors are disconnected when the outputs are configured as open-drain outputs (see
Section 7.4.11). Use the pull-up/pull-down selection registers to select either a pull-up or
pull-down resistor.
Table 14.
Bit
Pull-up/pull-down enable register (address 43h)
7
6
5
4
3
2
1
0
Symbol
PE7
PE6
PE5
PE4
PE3
PE2
PE1
PE0
Default
0
0
0
0
0
0
0
0
7.4.8 Pull-up/pull-down selection register (44h)
The I/O port can be configured to have pull-up or pull-down resistor by programming the
pull-up/pull-down selection register. Setting a bit to logic 1 selects a 100 k pull-up
resistor for that I/O pin. Setting a bit to logic 0 selects a 100 k pull-down resistor for that
I/O pin. If the pull-up/down feature is disconnected, writing to this register has no effect on
I/O pin. Typical value is 100 k with minimum of 50 k and maximum of 150 k.
Table 15.
Bit
Pull-up/pull-down selection register (address 44h)
7
6
5
4
3
2
1
0
Symbol
PUD7
PUD6
PUD5
PUD4
PUD3
PUD2
PUD1
PUD0
Default
1
1
1
1
1
1
1
1
7.4.9 Interrupt mask register (45h)
Interrupt mask register is set to logic 1 upon power-on, disabling interrupts during system
start-up. Interrupts may be enabled by setting corresponding mask bits to logic 0. If an
input changes state and the corresponding bit in the Interrupt mask register is set to 1, the
interrupt is masked and the interrupt pin (INT) is not asserted. If the corresponding bit in
the Interrupt mask register is set to 0, the interrupt pin is asserted.
When an input changes state and the resulting interrupt is masked (interrupt mask bit
is 1), setting the input mask register bit to 0 causes the interrupt pin to be asserted. If the
interrupt mask bit of an input that is currently the source of an interrupt is set to 1, the
interrupt pin is de-asserted.
Table 16.
Bit
PCAL6408A
Product data sheet
Interrupt mask register (address 45h)
7
6
5
4
3
2
1
0
Symbol
M7
M6
M5
M4
M3
M2
M1
M0
Default
1
1
1
1
1
1
1
1
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
7.4.10 Interrupt status register (46h)
This read-only register is used to identify the source of an interrupt. When read, a logic 1
indicates that the corresponding input pin was the source of the interrupt. A logic 0
indicates that the input pin is not the source of an interrupt.
When a corresponding bit in the interrupt mask register is set to 1 (masked), the interrupt
status bit returns logic 0.
Table 17.
Bit
Interrupt status register (address 46h)
7
6
5
4
3
2
1
0
Symbol
S7
S6
S5
S4
S3
S2
S1
S0
Default
0
0
0
0
0
0
0
0
7.4.11 Output port configuration register (4Fh)
The output port configuration register selects port-wise push-pull or open-drain I/O stage.
A logic 0 configures the I/O as push-pull (Q1 and Q2 are active, see Figure 9). A logic 1
configures the I/O as open-drain (Q1 is disabled, Q2 is active) and the recommended
command sequence is to program this register (4Fh) before the Configuration register
(03h) sets the port pins as outputs.
Table 18.
Bit
Output port configuration register (address 4Fh)
7
6
5
0
0
0
Symbol
Default
PCAL6408A
Product data sheet
4
3
2
1
0
0
0
reserved
0
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0
ODEN
0
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
7.5 I/O port
When an I/O is configured as an input, FETs Q1 and Q2 are off, which creates a
high-impedance input. The input voltage may be raised above VDD to a maximum of 5.5 V.
If the I/O is configured as an output, Q1 or Q2 is enabled, depending on the state of the
Output port register. In this case, there are low-impedance paths between the I/O pin and
either VDD(P) or VSS. The external voltage applied to this I/O pin should not exceed the
recommended levels for proper operation.
data from
shift register
data from
shift register
write
configuration
pulse
output port
register data
configuration
register
D
VDD(P)
Q
Q1
ESD
protection
diode
Q2
ESD
protection
diode
FF
CK
Q
D
Q
P0 to P7
FF
write pulse
CK
output port
register
VSS
D
Q
input port
register data
FF
read pulse
CK
VDD(P)
PULL-UP/PULL-DOWN
CONTROL
INTERRUPT
MASK
input port
register
100 kΩ
D
input latch
register
data from
shift register
D
data from
shift register
CK
Q
LATCH
Q
read pulse
FF
write input
latch pulse
to INT
polarity inversion
register
D
EN
input port
latch
Q
FF
write polarity
pulse
CK
002aah089
On power-up or reset, all registers return to default values.
Fig 9.
PCAL6408A
Product data sheet
Simplified schematic of the I/Os (P0 to P7)
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PCAL6408A
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Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
7.6 Power-on reset
When power (from 0 V) is applied to VDD(P), an internal power-on reset holds the
PCAL6408A in a reset condition until VDD(P) has reached VPOR. At that time, the reset
condition is released and the PCAL6408A registers and I2C-bus/SMBus state machine
initialize to their default states. After that, VDD(P) must be lowered to below VPOR and back
up to the operating voltage for a power-reset cycle. See Section 9.3 “Power-on reset
requirements”.
7.7 Reset input (RESET)
The RESET input can be asserted to initialize the system while keeping the VDD(P) at its
operating level. A reset can be accomplished by holding the RESET pin LOW for a
minimum of tw(rst). The PCAL6408A registers and I2C-bus/SMBus state machine are
changed to their default state once RESET is LOW (0). When RESET is HIGH (1), the I/O
levels at the P port can be changed externally or through the master. This input requires a
pull-up resistor to VDD(I2C-bus) if no active connection is used.
7.8 Interrupt output (INT)
An interrupt is generated by any rising or falling edge of the port inputs in the Input mode.
After time tv(INT), the signal INT is valid. Resetting the interrupt circuit is achieved when
data on the port is changed to the original setting or when data is read from the port that
generated the interrupt (see Figure 13). Resetting occurs in the Read mode at the
acknowledge (ACK) or not acknowledge (NACK) bit after the rising edge of the SCL
signal. Interrupts that occur during the ACK or NACK clock pulse can be lost (or be very
short) due to the resetting of the interrupt during this pulse. Each change of the I/Os after
resetting is detected and is transmitted as INT.
A pin configured as an output cannot cause an interrupt. Changing an I/O from an output
to an input may cause a false interrupt to occur, if the state of the pin does not match the
contents of the Input port register.
The INT output has an open-drain structure and requires a pull-up resistor to VDD(P) or
VDD(I2C-bus) depending on the application. INT should be connected to the voltage source
of the device that requires the interrupt information. When using the input latch feature,
the input pin state is latched. The interrupt is reset only when data is read from the port
that generated the interrupt. The reset occurs in the Read mode at the acknowledge
(ACK) or not acknowledge (NACK) bit after the rising edge of the SCL signal.
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
8. Bus transactions
The PCAL6408A is an I2C-bus slave device. Data is exchanged between the master and
PCAL6408A through write and read commands using I2C-bus. The two communication
lines are a serial data line (SDA) and a serial clock line (SCL). Both lines must be
connected to a positive supply via a pull-up resistor when connected to the output stages
of a device. Data transfer may be initiated only when the bus is not busy.
8.1 Write commands
Data is transmitted to the PCAL6408A by sending the device address and setting the
Least Significant Bit (LSB) to a logic 0 (see Figure 7 for device address). The command
byte is sent after the address and determines which register receives the data that follows
the command byte. There is no limitation on the number of data bytes sent in one write
transmission.
SCL
1
2
3
4
5
6
7
8
9
slave address
SDA S
1
0
0
0
AD
0
0 DR 0
START condition
A
R/W
0
0
0
0
0
0
STOP
condition
data to port
command byte
0
acknowledge
from slave
1
A
DATA 1
A
P
acknowledge
from slave
acknowledge
from slave
write to port
tv(Q)
data out from port
DATA 1 VALID
002aaf825
Fig 10. Write to Output port register
SCL
1
2
3
4
5
6
7
8
9
slave address
SDA S
0
1
0
0
START condition
0
AD
0 DR 0
R/W
A
0 1/0 0
0
0 1/0 1/0 1/0 A
acknowledge
from slave
STOP
condition
data to register
command byte
acknowledge
from slave
DATA 1
A
P
acknowledge
from slave
002aah090
Fig 11. Write to Configuration or Polarity inversion registers
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
8.2 Read commands
To read data from the PCAL6408A, the bus master must first send the PCAL6408A
address with the least significant bit set to a logic 0 (see Figure 7 for device address). The
command byte is sent after the address and determines which register is to be accessed.
After a restart the device address is sent again, but this time the LSB is set to a logic 1.
Data from the register defined by the command byte then is sent by the PCAL6408A (see
Figure 12 and Figure 13).
Data is clocked into the register on the rising edge of the ACK clock pulse. There is no
limit on the number of data bytes received in one read transmission, but on the final byte
received the bus master must not acknowledge the data.
slave address
SDA S
0
1
0
0
0
command byte
AD
DR
0
START condition
0
A
0
0
0
0
R/W
slave address
0
1
0
0
0
(repeated)
START condition
0
1 1/0 A
(cont.)
acknowledge
from slave
acknowledge
from slave
(cont.) S
0
data from register
0 AD 1
A
DR
DATA (first byte)
R/W
data from register
A
DATA (last byte)
acknowledge
from master
acknowledge
from slave
NA P
STOP
condition
no acknowledge
from master
at this moment master-transmitter becomes master-receiver
and slave-receiver becomes slave-transmitter
002aaf827
Fig 12. Read from register
SCL
1
2
3
4
5
6
7
8
9
slave address
SDA S
0
1
0
0
START condition
0
data from port
0
AD
DR
1
R/W
DATA 1
A
data from port
A
acknowledge from slave
DATA 4
acknowledge from master
read from
port
data into
port
DATA 1
DATA 2
th(D)
DATA 3
tsu(D)
INT
tv(INT)
trst(INT)
DATA 4
no acknowledge
from master
1
P
STOP
condition
DATA 5
INT is cleared by
read from port
STOP not needed
to clear INT
002aaf828
Transfer of data can be stopped at any time by a STOP condition. When this occurs, data present at the latest acknowledge
phase is valid (output mode). It is assumed that the command byte has previously been programmed with 00h (read Input port
register).
This figure eliminates the command byte transfer, a restart, and slave address call between the initial slave address call and
actual data transfer from P port (see Figure 12).
Fig 13. Read Input port register (non-latched)
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
SCL
1
2
3
4
5
6
7
8
9
slave address
SDA S
0
1
0
0
START condition
0
data from port
0 AD 1
DR
R/W
DATA 1
A
data from port
A
acknowledge from slave
DATA 2
acknowledge from master
read from
port
data into
port
DATA 1
tsu(D)
INT
tv(INT)
1
P
STOP
condition
DATA 1
DATA 2
th(D)
no acknowledge
from master
trst(INT)
INT is cleared by
read from port
STOP not needed
to clear INT
002aah091
Transfer of data can be stopped at any time by a STOP condition. When this occurs, data present at the latest acknowledge
phase is valid (output mode). It is assumed that the command byte has previously been programmed with 00h (read Input port
register).
This figure eliminates the command byte transfer, a restart, and slave address call between the initial slave address call and
actual data transfer from P port (see Figure 12).
Fig 14. Read Input port register (latch enabled)
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
9. Application design-in information
VDD(I2C-bus)
VDD(P)
VDD(I2C-bus) = 1.8 V
10 kΩ
10 kΩ
10 kΩ
10 kΩ
VDD
10 kΩ (× 3)
VDD(I2C-bus) VDD(P)
MASTER
CONTROLLER
SCL
SDA
P0
SCL
SDA
INT
RESET
SUBSYSTEM 1
(e.g., alarm system)
A
INT
RESET
VSS
ALARM(1)
P1
controlled
switch
enable
B
PCAL6408A
P2
P3
ADDR
P4
P5
KEYPAD
P6
VSS
P7
002aah092
Device address configured as 0100 000x for this example.
P0 and P2 through P4 are configured as inputs.
P1 and P5 through P7 are configured as outputs.
(1) Resistors are required for inputs (on P port) that may float. If a driver to an input will never let the input float, a resistor is not
needed. Outputs (in the P port) do not need pull-up resistors.
Fig 15. Typical application
9.1 Minimizing IDD when I/Os control LEDs
When the I/Os are used to control LEDs, normally they are connected to VDD through a
resistor as shown in Figure 15. The LED acts as a diode, so when the LED is off, the I/O
VI is about 1.2 V less than VDD. The IDD parameter in Table 23 “Static characteristics”
shows how IDD increases as VI becomes lower than VDD. Designs that must minimize
current consumption, such as battery power applications, should consider maintaining the
I/O pins greater than or equal to VDD when the LED is off.
Figure 16 shows a high-value resistor in parallel with the LED. Figure 17 shows VDD less
than the LED supply voltage by at least 1.2 V. Both of these methods maintain the I/O VI
at or above VDD and prevent additional supply current consumption when the LED is off.
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
3.3 V
VDD
VDD(P)
LED
5V
VDD(P)
100 kΩ
LED
Pn
Pn
002aah278
Fig 16. High-value resistor in parallel
with the LED
002aah279
Fig 17. Device supplied by a lower voltage
9.2 Output drive strength control
The Output drive strength registers allow the user to control the output drive level of the
GPIO. Each GPIO can be configured independently to one of the four possible output
current levels. By programming these bits the user is changing the number of transistor
pairs or ‘fingers’ that drive the I/O pad.
Figure 18 shows a simplified output stage. The behavior of the pad is affected by the
Configuration register, the output port data, and the current control register. When the
Current Control register bits are programmed to 10b, then only two of the fingers are
active, reducing the current drive capability by 50 %.
PMOS_EN0
VDD(P)
PMOS_EN1
Current Control
register
PMOS_EN[3:0]
DECODER
NMOS_EN[3:0]
PMOS_EN2
Configuration
register
PMOS_EN3
P0 to P7
Output port
register
NMOS_EN3
NMOS_EN2
NMOS_EN1
NMOS_EN0
002aah093
Fig 18. Simplified output stage
PCAL6408A
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Reducing the current drive capability may be desirable to reduce system noise. When the
output switches (transitions from H/L), there is a peak current that is a function of the
output drive selection. This peak current runs through VDD and VSS package inductance
and creates noise (some radiated, but more critically Simultaneous Switching Noise
(SSN)). In other words, switching many outputs at the same time creates ground and
supply noise. The output drive strength control through the Output Drive Strength
registers allows the user to mitigate SSN issues without the need of additional external
components.
9.3 Power-on reset requirements
In the event of a glitch or data corruption, PCAL6408A can be reset to its default
conditions by using the power-on reset feature. Power-on reset requires that the device
go through a power cycle to be completely reset. This reset also happens when the device
is powered on for the first time in an application.
The two types of power-on reset are shown in Figure 19 and Figure 20.
VDD(P)
ramp-up
ramp-down
re-ramp-up
td(rst)
time
(dV/dt)r
(dV/dt)f
time to re-ramp
when VDD(P) drops
below 0.2 V or to VSS
(dV/dt)r
002aag960
Fig 19. VDD is lowered below 0.2 V or 0 V and then ramped up to VDD
VDD(P)
ramp-down
ramp-up
td(rst)
VI drops below POR levels
(dV/dt)f
time to re-ramp
when VDD(P) drops
to VPOR(min) − 50 mV
time
(dV/dt)r
002aag961
Fig 20. VDD is lowered below the POR threshold, then ramped back up to VDD
Table 19 specifies the performance of the power-on reset feature for PCAL6408A for both
types of power-on reset.
PCAL6408A
Product data sheet
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Table 19. Recommended supply sequencing and ramp rates
Tamb = 25 C (unless otherwise noted). Not tested; specified by design.
Symbol
Parameter
Condition
Min
Typ
Max
Unit
(dV/dt)f
fall rate of change of voltage
Figure 19
0.1
-
2000
ms
(dV/dt)r
rise rate of change of voltage
Figure 19
0.1
-
2000
ms
td(rst)
reset delay time
Figure 19; re-ramp time when
VDD(P) drops below 0.2 V or to VSS
1
-
-
s
Figure 20; re-ramp time when
VDD(P) drops to VPOR(min)  50 mV
1
-
-
s
VDD(gl)
glitch supply voltage difference
Figure 21
[1]
-
-
1.0
V
[2]
-
-
10
s
tw(gl)VDD
supply voltage glitch pulse width
Figure 21
VPOR(trip)
power-on reset trip voltage
falling VDD(P)
0.7
-
-
V
rising VDD(P)
-
-
1.4
V
[1]
Level that VDD(P) can glitch down to with a ramp rate of 0.4 s/V, but not cause a functional disruption when tw(gl)VDD < 1 s.
[2]
Glitch width that will not cause a functional disruption when VDD(gl) = 0.5  VDD(P).
Glitches in the power supply can also affect the power-on reset performance of this
device. The glitch width (tw(gl)VDD) and glitch height (VDD(gl)) are dependent on each
other. The bypass capacitance, source impedance, and device impedance are factors that
affect power-on reset performance. Figure 21 and Table 19 provide more information on
how to measure these specifications.
VDD(P)
∆VDD(gl)
tw(gl)VDD
time
002aag962
Fig 21. Glitch width and glitch height
VPOR is critical to the power-on reset. VPOR is the voltage level at which the reset condition
is released and all the registers and the I2C-bus/SMBus state machine are initialized to
their default states. The value of VPOR differs based on the VDD being lowered to or from
0 V. Figure 22 and Table 19 provide more details on this specification.
VDD(P)
VPOR (rising VDD(P))
VPOR (falling VDD(P))
time
POR
time
002aag963
Fig 22. Power-on reset voltage (VPOR)
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
9.4 Device current consumption with internal pull-up and pull-down
resistors
The PCAL6408A integrates programmable pull-up and pull-down resistors to eliminate
external components when pins are configured as inputs and pull-up or pull-down
resistors are required (for example, nothing is driving the inputs to the power supply rails.
Since these pull-up and pull-down resistors are internal to the device itself, they contribute
to the current consumption of the device and must be considered in the overall system
design.
The pull-up or pull-down function is selected in register 44h, while the resistor is
connected by the enable register 43h. The configuration of the resistors is shown in
Figure 9.
If the resistor is configured as a pull-up, that is, connected to VDD, a current flows from the
VDD(P) pin through the resistor to ground when the pin is held LOW. This current appears
as additional IDD upsetting any current consumption measurements.
In the same manner, if the resistor is configured as a pull-down and the pin is held HIGH,
current flows from the power supply through the pin to the VSS pin. While this current is
not measured as part of IDD, one must be mindful of the 200 mA limiting value through
VSS.
The pull-up and pull-down resistors are simple resistors and the current is linear with
voltage. The resistance specification for these devices spans from 50 k with a nominal
100 k value. Any current flow through these resistors is additive by the number of pins
held HIGH or LOW and the current can be calculated by Ohm’s law. See Figure 26 for a
graph of supply current versus the number of pull-up resistors.
PCAL6408A
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
10. Limiting values
Table 20. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
VDD(I2C-bus)
I2C-bus
Conditions
Min
Max
Unit
0.5
+6.5
V
VDD(P)
supply voltage port P
VI
input voltage
[1]
0.5
+6.5
V
0.5
+6.5
VO
output voltage
[1]
V
0.5
+6.5
V
IIK
input clamping current
ADDR, RESET, SCL; VI < 0 V
-
20
mA
IOK
IIOK
output clamping current
INT; VO < 0 V
-
20
mA
input/output clamping current
P port; VO < 0 V or VO > VDD(P)
-
20
mA
SDA; VO < 0 V or VO > VDD(I2C-bus)
-
20
mA
supply voltage
IOL
LOW-level output current
continuous; P port; VO = 0 V to VDD(P)
-
50
mA
continuous; SDA, INT; VO = 0 V to VDD(I2C-bus)
-
25
mA
IOH
HIGH-level output current
continuous; P port; VO = 0 V to VDD(P)
-
25
mA
IDD
supply current
continuous through VSS
-
200
mA
IDD(P)
supply current port P
continuous through VDD(P)
-
160
mA
IDD(I2C-bus)
I2C-bus
continuous through VDD(I2C-bus)
-
10
mA
Tstg
storage temperature
65
+150
C
[1]
supply current
The input negative-voltage and output voltage ratings may be exceeded if the input and output current ratings are observed.
11. Recommended operating conditions
Table 21.
Operating conditions
Symbol
Parameter
VDD(I2C-bus)
I2C-bus
VDD(P)
supply voltage port P
VIH
HIGH-level input voltage
VIL
Conditions
supply voltage
LOW-level input voltage
Min
Max
Unit
1.65
5.5
V
1.65
5.5
V
SCL, SDA, RESET
0.7  VDD(I2C-bus)
5.5
V
ADDR, P7 to P0
0.7  VDD(P)
5.5
V
SCL, SDA, RESET
0.5
0.3  VDD(I2C-bus)
V
ADDR, P7 to P0
0.5
0.3  VDD(P)
V
IOH
HIGH-level output current
P7 to P0
-
10
mA
IOL
LOW-level output current
P7 to P0
-
25
mA
Tamb
ambient temperature
operating in free air
40
+85
C
PCAL6408A
Product data sheet
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23 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
12. Thermal characteristics
Table 22.
Symbol
Zth(j-a)
[1]
Thermal characteristics
Parameter
Conditions
transient thermal impedance from junction to ambient
Max
Unit
TSSOP16 package
[1]
108
K/W
HVQFN16 package
[1]
53
K/W
XQFN16 package
[1]
184
K/W
The package thermal impedance is calculated in accordance with JESD 51-7.
13. Static characteristics
Table 23. Static characteristics
Tamb = 40 C to +85 C; VDD(I2C-bus) = 1.65 V to 5.5 V; unless otherwise specified.
Min
Typ[1] Max
Unit
1.2
-
-
V
-
1
1.4
V
VDD(P) = 1.65 V
1.2
-
-
V
VDD(P) = 2.3 V
1.8
-
-
V
VDD(P) = 3 V
2.6
-
-
V
VDD(P) = 4.5 V
4.1
-
-
V
VDD(P) = 1.65 V
1.1
-
-
V
VDD(P) = 2.3 V
1.7
-
-
V
VDD(P) = 3 V
2.5
-
-
V
VDD(P) = 4.5 V
4.0
-
-
V
VDD(P) = 1.65 V
-
-
0.45
V
VDD(P) = 2.3 V
-
-
0.25
V
VDD(P) = 3 V
-
-
0.25
V
VDD(P) = 4.5 V
-
-
0.2
V
VDD(P) = 1.65 V
-
-
0.5
V
VDD(P) = 2.3 V
-
-
0.3
V
VDD(P) = 3 V
-
-
0.25
V
VDD(P) = 4.5 V
-
-
0.2
V
Symbol
Parameter
Conditions
VIK
input clamping voltage
II = 18 mA; VDD(P) = 1.65 V to 5.5 V
VPOR
power-on reset voltage
VI = VDD(P) or VSS; IO = 0 mA;
VDD(P) = 1.65 V to 5.5 V
VOH
HIGH-level output
voltage[3]
P port; IOH = 8 mA; CCX = 11b
[2]
P port; IOH = 2.5 mA and CCX = 00b;
IOH = 5 mA and CCX = 01b;
IOH = 7.5 mA and CCX = 10b;
IOH = 10 mA and CCX = 11b;
VOL
LOW-level
output voltage[3]
P port; IOL = 8 mA; CCX = 11b
P port; IOL = 2.5 mA and CCX = 00b;
IOL = 5 mA and CCX = 01b;
IOL = 7.5 mA and CCX = 10b;
IOL = 10 mA and CCX = 11b;
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
24 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Table 23. Static characteristics …continued
Tamb = 40 C to +85 C; VDD(I2C-bus) = 1.65 V to 5.5 V; unless otherwise specified.
Symbol
IOL
Parameter
LOW-level output current
Min
Typ[1] Max
Unit
3
-
-
mA
3
15[5]
-
mA
SCL, SDA, RESET; VI = VDD(I2C-bus) or VSS
-
-
1
A
ADDR; VI = VDD(P) or VSS
-
-
1
A
Conditions
VOL = 0.4 V; VDD(P) = 1.65 V to 5.5 V
SDA
INT
II
input current
[4]
VDD(P) = 1.65 V to 5.5 V
IIH
HIGH-level input current
P port; VI = VDD(P); VDD(P) = 1.65 V to 5.5 V
-
-
1
A
IIL
LOW-level input current
P port; VI = VSS; VDD(P) = 1.65 V to 5.5 V
-
-
1
A
IDD
supply current
IDD(I2C-bus) + IDD(P); Operating mode;
SDA, P port, ADDR, RESET;
VI on SDA and RESET = VDD(I2C-bus) or VSS;
VI on P port and ADDR = VDD(P) or VSS;
IO = 0 mA; I/O = inputs; fSCL = 400 kHz
VDD(P) = 3.6 V to 5.5 V
-
10
25
A
VDD(P) = 2.3 V to 3.6 V
-
6.5
15
A
VDD(P) = 1.65 V to 2.3 V
-
4
9
A
VDD(P) = 3.6 V to 5.5 V
-
1.5
7
A
VDD(P) = 2.3 V to 3.6 V
-
1
3.2
A
VDD(P) = 1.65 V to 2.3 V
-
0.5
1.7
A
IDD(I2C-bus) + IDD(P); Standby mode;
SCL, SDA, P port, ADDR, RESET;
VI on SCL, SDA and RESET = VDD(I2C-bus) or VSS;
VI on P port and ADDR = VDD(P);
IO = 0 mA; I/O = inputs; fSCL = 0 kHz
Active mode; IDD(I2C-bus) + IDD(P);
P port, ADDR, RESET;
VI on RESET = VDD(I2C-bus);
VI on P port and ADDR = VDD(P);
IO = 0 mA; I/O = inputs;
fSCL = 400 kHz, continuous register read
VDD(P) = 3.6 V to 5.5 V
-
60
125
A
VDD(P) = 2.3 V to 3.6 V
-
40
75
A
VDD(P) = 1.65 V to 2.3 V
-
20
45
A
-
0.55
0.75
mA
with pull-ups enabled;
IDD(I2C-bus) + IDD(P); P port, ADDR, RESET;
VI on SCL, SDA and RESET = VDD(I2C-bus) or VSS;
VI on P port = VSS;
VI on ADDR = VDD(I2C-bus) or VSS;
IO = 0 mA; I/O = inputs with pull-up enabled;
fSCL = 0 kHz
VDD(P) = 1.65 V to 5.5 V
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
25 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Table 23. Static characteristics …continued
Tamb = 40 C to +85 C; VDD(I2C-bus) = 1.65 V to 5.5 V; unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ[1] Max
Unit
IDD
additional quiescent
supply current[6]
SCL, SDA, RESET;
one input at VDD(I2C-bus)  0.6 V,
other inputs at VDD(I2C-bus) or VSS;
VDD(P) = 1.65 V to 5.5 V
-
-
25
A
P port, ADDR;
one input at VDD(P)  0.6 V,
other inputs at VDD(P) or VSS;
VDD(P) = 1.65 V to 5.5 V
-
-
80
A
Ci
input capacitance
SCL; VI = VDD(I2C-bus) or VSS;
VDD(P) = 1.65 V to 5.5 V
-
6
7
pF
Cio
input/output capacitance
SDA; VI/O = VDD(I2C-bus) or VSS;
VDD(P) = 1.65 V to 5.5 V
-
7
8
pF
P port; VI/O = VDD(P) or VSS;
VDD(P) = 1.65 V to 5.5 V
-
7.5
8.5
pF
Rpu(int)
internal pull-up resistance input/output
50
100
150
k
Rpd(int)
internal pull-down
resistance
50
100
150
k
input/output
[1]
All typical values are at nominal supply voltage (1.8 V, 2.5 V, 3.3 V or 5 V VDD) and Tamb = 25 C.
[2]
When power (from 0 V) is applied to VDD(P), an internal power-on reset holds the PCAL6408A in a reset condition until VDD(P) has
reached VPOR. At that time, the reset condition is released, and the PCAL6408A registers and I2C-bus/SMBus state machine initialize to
their default states. After that, VDD(P) must be lowered to below 0.2 V and back up to the operating voltage for a power-reset cycle.
[3]
The total current sourced by all I/Os must be limited to 80 mA.
[4]
Each I/O must be externally limited to a maximum of 25 mA, for a device total of 200 mA.
[5]
Typical value for Tamb = 25 C. VOL = 0.4 V and VDD = 3.3 V. Typical value for VDD < 2.5 V, VOL = 0.6 V.
[6]
Internal pull-up/pull-down resistor disabled.
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
26 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
13.1 Typical characteristics
002aag973
20
IDD
(μA)
002aag974
1400
IDD(stb)
(nA)
16
VDD(P) = 5.5 V
5.0 V
3.6 V
12
3.3 V
2.5 V
2.3 V
8
VDD(P) = 5.5 V
5.0 V
3.6 V
3.3 V
1000
800
600
400
2.5 V
2.3 V
1.8 V
1.65 V
4
0
−40
200
VDD(P) = 1.8 V
1.65 V
−15
10
35
60
85
Tamb (°C)
Fig 23. Supply current versus ambient temperature
002aag975
20
IDD
(μA)
16
0
−40
−15
10
35
60
85
Tamb (°C)
Fig 24. Standby supply current versus
ambient temperature
002aah245
600
Tamb = −40 °C
25 °C
85 °C
IDD(P)
(μA)
400
12
8
200
4
0
1.5
0
2.5
3.5
4.5
5.5
VDD(P) (V)
Tamb = 25 C
Product data sheet
2
4
6
8
number of I/O held LOW
VDD(P) = 5 V
Fig 25. Supply current versus supply voltage
PCAL6408A
0
Fig 26. Supply current versus number of I/O held LOW
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
27 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Isink
(mA)
002aaf578
35
Isink
(mA)
30
Tamb = −40 °C
25 °C
85 °C
25
002aaf579
35
30
Tamb = −40 °C
25 °C
85 °C
25
20
20
15
15
10
10
5
5
0
0
0
0.1
0.2
0.3
0
0.1
0.2
VOL (V)
a. VDD(P) = 1.65 V
Isink
(mA)
b. VDD(P) = 1.8 V
002aaf580
50
002aaf581
60
Isink
(mA)
40
Tamb = −40 °C
25 °C
85 °C
30
0.3
VOL (V)
Tamb = −40 °C
25 °C
85 °C
40
20
20
10
0
0
0
0.1
0.2
0.3
0
0.1
0.2
VOL (V)
c. VDD(P) = 2.5 V
Isink
(mA)
d. VDD(P) = 3.3 V
002aaf582
70
Isink
(mA)
Tamb = −40 °C
25 °C
85 °C
60
50
0.3
VOL (V)
002aaf583
70
Tamb = −40 °C
25 °C
85 °C
60
50
40
40
30
30
20
20
10
10
0
0
0
0.1
0.2
0.3
0
0.1
VOL (V)
e. VDD(P) = 5.0 V
0.2
0.3
VOL (V)
f. VDD(P) = 5.5 V
Fig 27. I/O sink current versus LOW-level output voltage with CCX.X = 11b
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
28 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
002aaf561
30
Isource
(mA)
Isource
(mA)
Tamb = −40 °C
25 °C
85 °C
20
002aaf562
35
Tamb = −40 °C
25 °C
85 °C
30
25
20
15
10
10
5
0
0
0
0.2
0.4
0.6
VDD(P) − VOH (V)
a. VDD(P) = 1.65 V
0
002aaf563
Isource
(mA)
Tamb = −40 °C
25 °C
85 °C
40
0.4
0.6
VDD(P) − VOH (V)
b. VDD(P) = 1.8 V
60
Isource
(mA)
0.2
002aaf564
70
Tamb = −40 °C
25 °C
85 °C
60
50
40
30
20
20
10
0
0
0
0.2
0.4
0.6
VDD(P) − VOH (V)
c. VDD(P) = 2.5 V
002aaf565
0.4
0.6
VDD(P) − VOH (V)
002aaf566
90
Isource
(mA)
Tamb = −40 °C
25 °C
85 °C
60
0.2
d. VDD(P) = 3.3 V
90
Isource
(mA)
0
Tamb = −40 °C
25 °C
85 °C
60
30
30
0
0
0
0.2
e. VDD(P) = 5.0 V
0.4
0.6
VDD(P) − VOH (V)
0
0.2
0.4
0.6
VDD(P) − VOH (V)
f. VDD(P) = 5.5 V
Fig 28. I/O source current versus HIGH-level output voltage with CCX.X = 11b
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
29 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
VOL
(mV)
002aah056
120
100
002aah057
200
VDD(P) − VOH (mV)
160
(1)
80
120
VDD(P) = 1.8 V
5V
60
(2)
80
40
(4)
20
0
−40
40
(3)
−15
10
35
60
85
Tamb (°C)
0
−40
−15
10
35
60
85
Tamb (°C)
Isource = 10 mA
(1) VDD(P) = 1.8 V; Isink = 10 mA
(2) VDD(P) = 5 V; Isink = 10 mA
(3) VDD(P) = 1.8 V; Isink = 1 mA
(4) VDD(P) = 5 V; Isink = 1 mA
Fig 29. LOW-level output voltage versus temperature
PCAL6408A
Product data sheet
Fig 30. I/O high voltage versus temperature
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
30 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
14. Dynamic characteristics
Table 24. I2C-bus interface timing requirements
Over recommended operating free air temperature range, unless otherwise specified. See Figure 31.
Conditions
Standard-mode
I2C-bus
Fast-mode I2C-bus
Symbol
Parameter
Unit
Min
Max
Min
Max
fSCL
SCL clock frequency
0
100
0
400
tHIGH
HIGH period of the SCL clock
4
-
0.6
-
s
tLOW
LOW period of the SCL clock
4.7
-
1.3
-
s
tSP
pulse width of spikes that must
be suppressed by the input filter
0
50
0
50
ns
tSU;DAT
data set-up time
250
-
100
-
ns
tHD;DAT
data hold time
0
-
0
-
ns
kHz
tr
rise time of both SDA and SCL signals
-
1000
20
300
ns
tf
fall time of both SDA and SCL signals
-
300
20 
(VDD / 5.5 V)
300
ns
tBUF
bus free time between a STOP and
START condition
4.7
-
1.3
-
s
tSU;STA
set-up time for a repeated START
condition
4.7
-
0.6
-
s
tHD;STA
hold time (repeated) START condition
4
-
0.6
-
s
tSU;STO
set-up time for STOP condition
4
-
0.6
-
s
tVD;DAT
data valid time
SCL LOW to
SDA output valid
-
3.45
-
0.9
s
tVD;ACK
data valid acknowledge time
ACK signal from
SCL LOW to
SDA (out) LOW
-
3.45
-
0.9
s
Table 25. Reset timing requirements
Over recommended operating free air temperature range, unless otherwise specified. See Figure 34.
Symbol
Parameter
Conditions
Standard-mode
I2C-bus
Fast-mode
I2C-bus
Min
Max
Min
Max
Unit
tw(rst)
reset pulse width
30
-
30
-
ns
trec(rst)
reset recovery time
200
-
200
-
ns
trst
reset time
600
-
600
-
ns
PCAL6408A
Product data sheet
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© NXP B.V. 2013. All rights reserved.
31 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Table 26. Switching characteristics
Over recommended operating free air temperature range; CL  100 pF; unless otherwise specified. See Figure 33.
Symbol
Parameter
Conditions
Standard-mode
I2C-bus
Fast-mode
I2C-bus
Min
Max
Min
Max
Unit
tv(INT)
valid time on pin INT
from P port to INT
-
1
-
1
s
trst(INT)
reset time on pin INT
from SCL to INT
-
1
-
1
s
tv(Q)
data output valid time
from SCL to P port
-
400
-
400
ns
tsu(D)
data input set-up time
from P port to SCL
0
-
0
-
ns
th(D)
data input hold time
from P port to SCL
300
-
300
-
ns
15. Parameter measurement information
VDD(I2C-bus)
RL = 1 kΩ
DUT
SDA
CL = 50 pF
002aag977
a. SDA load configuration
two bytes for read Input port register(1)
STOP
START
condition condition
(P)
(S)
Address
Bit 7
(MSB)
Address
Bit 1
R/W
Bit 0
(LSB)
ACK
(A)
Data
Bit 7
(MSB)
Data
Bit 0
(LSB)
STOP
condition
(P)
002aag952
b. Transaction format
tHIGH
tLOW
tSP
0.7 × VDD(I2C-bus)
0.3 × VDD(I2C-bus)
SCL
tBUF
tVD;DAT
tr
tf
tf(o)
tVD;ACK
tSU;STA
0.7 × VDD(I2C-bus)
SDA
tf
tHD;STA
tr
0.3 × VDD(I2C-bus)
tVD;ACK
tSU;DAT
tSU;STO
tHD;DAT
repeat START condition
STOP condition
002aag978
c. Voltage waveforms
CL includes probe and jig capacitance.
All inputs are supplied by generators having the following characteristics: PRR  10 MHz; Zo = 50 ; tr/tf  30 ns.
All parameters and waveforms are not applicable to all devices.
Byte 1 = I2C-bus address; Byte 2, byte 3 = P port data.
(1) See Figure 13.
Fig 31. I2C-bus interface load circuit and voltage waveforms
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
32 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
VDD(I2C-bus)
RL = 4.7 kΩ
INT
DUT
CL = 100 pF
002aag979
a. Interrupt load configuration
acknowledge
from slave
START condition
R/W
8 bits (one data byte)
from port
slave address
SDA S
SCL
0
1
0
1
2
3
0
4
0
5
0 AD 1
DR
6
7
8
acknowledge
from slave
DATA 1
A
no acknowledge
from master
STOP
condition
data from port
A
DATA 2
1
P
9
B
trst(INT) B
trst(INT)
INT
tv(INT)
data into
port
A
A
tsu(D)
ADDRESS
INT
DATA 1
0.5 × VDD(I2C-bus)
SCL
DATA 2
R/W
0.3 × VDD(I2C-bus)
tv(INT)
trst(INT)
0.5 × VDD(P)
Pn
0.7 × VDD(I2C-bus)
A
0.5 × VDD(I2C-bus)
INT
View A - A
View B - B
002aag980
b. Voltage waveforms
CL includes probe and jig capacitance.
All inputs are supplied by generators having the following characteristics: PRR  10 MHz; Zo = 50 ; tr/tf  30 ns.
All parameters and waveforms are not applicable to all devices.
Fig 32. Interrupt load circuit and voltage waveforms
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
33 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
500 Ω
Pn
DUT
2 × VDD(P)
CL = 50 pF
500 Ω
002aag981
a. P port load configuration
SCL
P0
A
P7
0.7 × VDD(I2C-bus)
0.3 × VDD(I2C-bus)
SDA
tv(Q)
Pn
unstable
data
last stable bit
A
P7
002aag982
b. Write mode (R/W = 0)
SCL
P0
0.7 × VDD(I2C-bus)
0.3 × VDD(I2C-bus)
tsu(D)
th(D)
Pn
0.5 × VDD(P)
002aag983
c. Read mode (R/W = 1)
CL includes probe and jig capacitance.
tv(Q) is measured from 0.7  VDD(I2C-bus) on SCL to 50 % I/O (Pn) output.
All inputs are supplied by generators having the following characteristics: PRR  10 MHz; Zo = 50 ; tr/tf  30 ns.
The outputs are measured one at a time, with one transition per measurement.
All parameters and waveforms are not applicable to all devices.
Fig 33. P port load circuit and voltage waveforms
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
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PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
VDD(I2C-bus)
RL = 1 kΩ
SDA
DUT
500 Ω
Pn
DUT
CL = 50 pF
2 × VDD(P)
CL = 50 pF
500 Ω
002aag977
002aag981
a. SDA load configuration
b. P port load configuration
START
SCL
ACK or read cycle
SDA
0.3 × VDD(I2C-bus)
trst
RESET
0.5 × VDD(I2C-bus)
trec(rst)
tw(rst)
trec(rst)
trst
Pn
0.5 × VDD(P)
002aag984
c. RESET timing
CL includes probe and jig capacitance.
All inputs are supplied by generators having the following characteristics: PRR  10 MHz; Zo = 50 ; tr/tf  30 ns.
The outputs are measured one at a time, with one transition per measurement.
I/Os are configured as inputs.
All parameters and waveforms are not applicable to all devices.
Fig 34. Reset load circuits and voltage waveforms
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
35 of 49
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NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
16. Package outline
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
36 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
37 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
38 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
39 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
17. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note AN10365 “Surface mount reflow
soldering description”.
17.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
17.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
• Through-hole components
• Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
•
•
•
•
•
•
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
17.3 Wave soldering
Key characteristics in wave soldering are:
• Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
• Solder bath specifications, including temperature and impurities
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
40 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
17.4 Reflow soldering
Key characteristics in reflow soldering are:
• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 39) than a SnPb process, thus
reducing the process window
• Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
• Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 27 and 28
Table 27.
SnPb eutectic process (from J-STD-020D)
Package thickness (mm)
Package reflow temperature (C)
Volume (mm3)
< 350
 350
< 2.5
235
220
 2.5
220
220
Table 28.
Lead-free process (from J-STD-020D)
Package thickness (mm)
Package reflow temperature (C)
Volume (mm3)
< 350
350 to 2000
> 2000
< 1.6
260
260
260
1.6 to 2.5
260
250
245
> 2.5
250
245
245
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 39.
PCAL6408A
Product data sheet
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Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
41 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
temperature
maximum peak temperature
= MSL limit, damage level
minimum peak temperature
= minimum soldering temperature
peak
temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 39. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365
“Surface mount reflow soldering description”.
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
42 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
18. Soldering: PCB footprints
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
43 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
44 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
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PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
45 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
19. Abbreviations
Table 29.
Abbreviations
Acronym
Description
ESD
ElectroStatic Discharge
FET
Field-Effect Transistor
GPIO
General-Purpose Input/Output
I2C-bus
Inter-Integrated Circuit bus
I/O
Input/Output
LED
Light-Emitting Diode
LSB
Least Significant Bit
MSB
Most Significant Bit
PCB
Printed-Circuit Board
POR
Power-On Reset
SMBus
System Management Bus
20. Revision history
Table 30.
Revision history
Document ID
Release date
Data sheet status
Change notice
Supersedes
PCAL6408A v.3
20130918
Product data sheet
-
PCAL6408A v.2
Modifications:
•
•
•
•
•
•
•
Section 2 “Features and benefits”, 17th bullet item: added “XFBGA16”
Table 1 “Ordering information”: added Type number PCAL6408AEX
Table 2 “Ordering options”: added Type number PCAL6408AEX
Added (new) Figure 5 “Pin configuration for 1.6 mm  1.6 mm XFBGA16”
Added (new) Figure 6 “Ball mapping for 1.6 mm  1.6 mm XFBGA16”
Table 3 “Pin description”: added column “XFBGA16”
Table 6 “Command byte”, register “Output port configuration”:
– Pointer register bits corrected from “0100 0111” to “0100 1111” (correction to documentation,
no functional change to device)
– Command byte corrected from “47h” to “4Fh” (correction to documentation, no functional
change to device)
•
Section 7.4.11 “Output port configuration register (4Fh)”:
– register number corrected from “47h” to “4Fh” in Section title (correction to documentation,
no functional change to device)
– first paragraph, third sentence: register number corrected from “(47h)” to “(4Fh)” (correction
to documentation, no functional change to device)
– register number corrected from “47h” to “4Fh” in title of Table 18 (correction to
documentation, no functional change to device)
•
Added (new) Figure 38 “Package outline SOT1354-1 (XFBGA16)”
PCAL6408A v.2
20121206
Product data sheet
-
PCAL6408A v.1
PCAL6408A v.1
20120906
Product data sheet
-
-
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
46 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
21. Legal information
21.1 Data sheet status
Document status[1][2]
Product status[3]
Definition
Objective [short] data sheet
Development
This document contains data from the objective specification for product development.
Preliminary [short] data sheet
Qualification
This document contains data from the preliminary specification.
Product [short] data sheet
Production
This document contains the product specification.
[1]
Please consult the most recently issued document before initiating or completing a design.
[2]
The term ‘short data sheet’ is explained in section “Definitions”.
[3]
The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
21.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
Product specification — The information and data provided in a Product
data sheet shall define the specification of the product as agreed between
NXP Semiconductors and its customer, unless NXP Semiconductors and
customer have explicitly agreed otherwise in writing. In no event however,
shall an agreement be valid in which the NXP Semiconductors product is
deemed to offer functions and qualities beyond those described in the
Product data sheet.
21.3 Disclaimers
Limited warranty and liability — Information in this document is believed to
be accurate and reliable. However, NXP Semiconductors does not give any
representations or warranties, expressed or implied, as to the accuracy or
completeness of such information and shall have no liability for the
consequences of use of such information. NXP Semiconductors takes no
responsibility for the content in this document if provided by an information
source outside of NXP Semiconductors.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
PCAL6408A
Product data sheet
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in life support, life-critical or
safety-critical systems or equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors and its suppliers accept no liability for
inclusion and/or use of NXP Semiconductors products in such equipment or
applications and therefore such inclusion and/or use is at the customer’s own
risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Customers are responsible for the design and operation of their applications
and products using NXP Semiconductors products, and NXP Semiconductors
accepts no liability for any assistance with applications or customer product
design. It is customer’s sole responsibility to determine whether the NXP
Semiconductors product is suitable and fit for the customer’s applications and
products planned, as well as for the planned application and use of
customer’s third party customer(s). Customers should provide appropriate
design and operating safeguards to minimize the risks associated with their
applications and products.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on any weakness or default in the
customer’s applications or products, or the application or use by customer’s
third party customer(s). Customer is responsible for doing all necessary
testing for the customer’s applications and products using NXP
Semiconductors products in order to avoid a default of the applications and
the products or of the application or use by customer’s third party
customer(s). NXP does not accept any liability in this respect.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) will cause permanent
damage to the device. Limiting values are stress ratings only and (proper)
operation of the device at these or any other conditions above those given in
the Recommended operating conditions section (if present) or the
Characteristics sections of this document is not warranted. Constant or
repeated exposure to limiting values will permanently and irreversibly affect
the quality and reliability of the device.
Terms and conditions of commercial sale — NXP Semiconductors
products are sold subject to the general terms and conditions of commercial
sale, as published at http://www.nxp.com/profile/terms, unless otherwise
agreed in a valid written individual agreement. In case an individual
agreement is concluded only the terms and conditions of the respective
agreement shall apply. NXP Semiconductors hereby expressly objects to
applying the customer’s general terms and conditions with regard to the
purchase of NXP Semiconductors products by customer.
No offer to sell or license — Nothing in this document may be interpreted or
construed as an offer to sell products that is open for acceptance or the grant,
conveyance or implication of any license under any copyrights, patents or
other industrial or intellectual property rights.
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
47 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from competent authorities.
Non-automotive qualified products — Unless this data sheet expressly
states that this specific NXP Semiconductors product is automotive qualified,
the product is not suitable for automotive use. It is neither qualified nor tested
in accordance with automotive testing or application requirements. NXP
Semiconductors accepts no liability for inclusion and/or use of
non-automotive qualified products in automotive equipment or applications.
In the event that customer uses the product for design-in and use in
automotive applications to automotive specifications and standards, customer
(a) shall use the product without NXP Semiconductors’ warranty of the
product for such automotive applications, use and specifications, and (b)
whenever customer uses the product for automotive applications beyond
NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any
liability, damages or failed product claims resulting from customer design and
use of the product for automotive applications beyond NXP Semiconductors’
standard warranty and NXP Semiconductors’ product specifications.
Translations — A non-English (translated) version of a document is for
reference only. The English version shall prevail in case of any discrepancy
between the translated and English versions.
21.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP B.V.
22. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
PCAL6408A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 18 September 2013
© NXP B.V. 2013. All rights reserved.
48 of 49
PCAL6408A
NXP Semiconductors
Low-voltage translating, 8-bit I2C-bus/SMBus I/O expander
23. Contents
1
General description . . . . . . . . . . . . . . . . . . . . . . 1
2
Features and benefits . . . . . . . . . . . . . . . . . . . . 2
2.1
Agile I/O features . . . . . . . . . . . . . . . . . . . . . . . 3
3
Ordering information . . . . . . . . . . . . . . . . . . . . . 3
3.1
Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 4
4
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5
Pinning information . . . . . . . . . . . . . . . . . . . . . . 5
5.1
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.2
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 6
6
Voltage translation . . . . . . . . . . . . . . . . . . . . . . . 7
7
Functional description . . . . . . . . . . . . . . . . . . . 7
7.1
Device address . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.2
Interface definition . . . . . . . . . . . . . . . . . . . . . . 8
7.3
Pointer register and command byte . . . . . . . . . 8
7.4
Register descriptions . . . . . . . . . . . . . . . . . . . . 9
7.4.1
Input port register (00h) . . . . . . . . . . . . . . . . . . 9
7.4.2
Output port register (01h) . . . . . . . . . . . . . . . . . 9
7.4.3
Polarity inversion register (02h) . . . . . . . . . . . . 9
7.4.4
Configuration register (03h) . . . . . . . . . . . . . . . 9
7.4.5
Output drive strength registers (40h, 41h) . . . 10
7.4.6
Input latch register (42h). . . . . . . . . . . . . . . . . 10
7.4.7
Pull-up/pull-down enable register (43h) . . . . . 11
7.4.8
Pull-up/pull-down selection register (44h). . . . 11
7.4.9
Interrupt mask register (45h) . . . . . . . . . . . . . 11
7.4.10
Interrupt status register (46h) . . . . . . . . . . . . . 12
7.4.11
Output port configuration register (4Fh) . . . . . 12
7.5
I/O port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.6
Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . 14
7.7
Reset input (RESET) . . . . . . . . . . . . . . . . . . . 14
7.8
Interrupt output (INT) . . . . . . . . . . . . . . . . . . . 14
8
Bus transactions . . . . . . . . . . . . . . . . . . . . . . . 15
8.1
Write commands. . . . . . . . . . . . . . . . . . . . . . . 15
8.2
Read commands . . . . . . . . . . . . . . . . . . . . . . 16
9
Application design-in information . . . . . . . . . 18
9.1
Minimizing IDD when I/Os control LEDs . . . . . 18
9.2
Output drive strength control . . . . . . . . . . . . . 19
9.3
Power-on reset requirements . . . . . . . . . . . . . 20
9.4
Device current consumption with internal
pull-up and pull-down resistors . . . . . . . . . . . . 22
10
Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 23
11
Recommended operating conditions. . . . . . . 23
12
Thermal characteristics . . . . . . . . . . . . . . . . . 24
13
Static characteristics. . . . . . . . . . . . . . . . . . . . 24
13.1
Typical characteristics . . . . . . . . . . . . . . . . . . 27
14
Dynamic characteristics . . . . . . . . . . . . . . . . . 31
15
16
17
17.1
17.2
17.3
17.4
18
19
20
21
21.1
21.2
21.3
21.4
22
23
Parameter measurement information . . . . . .
Package outline. . . . . . . . . . . . . . . . . . . . . . . .
Soldering of SMD packages . . . . . . . . . . . . . .
Introduction to soldering. . . . . . . . . . . . . . . . .
Wave and reflow soldering. . . . . . . . . . . . . . .
Wave soldering . . . . . . . . . . . . . . . . . . . . . . .
Reflow soldering . . . . . . . . . . . . . . . . . . . . . .
Soldering: PCB footprints . . . . . . . . . . . . . . .
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . .
Revision history . . . . . . . . . . . . . . . . . . . . . . .
Legal information . . . . . . . . . . . . . . . . . . . . . .
Data sheet status . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . .
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . .
Contact information . . . . . . . . . . . . . . . . . . . .
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
36
40
40
40
40
41
43
46
46
47
47
47
47
48
48
49
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2013.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
Date of release: 18 September 2013
Document identifier: PCAL6408A
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