pca9535ecmttxg ON Semiconductor, pca9535ecmttxg Datasheet - Page 13

• Manufacturer Part Number: pca9535ecmttxg
• Description: Pca9535e, Pca9535ec 16-bit Low-power I/o Expander For I2c Bus With Interrupt
• Manufacturer: ON Semiconductor

Interrupt Output
pin configured as an input changes state. The interrupt is
deactivated when the input pin returns to its previous state
or when the Input Port register is read (see Figure 9). A pin
configured as an output cannot cause an interrupt. Since
Minimizing I
LEDs
normally connected to V
Figure 11. The LED acts as a diode. When the LED is off,
the I/O V
I
as battery power applications, it is recommended that the I/O
DD
(5 V)
V
The open−drain interrupt output is activated when an I/O
To use the PCA9535E I/Os to control LEDs, the I/Os are
For applications requiring low current consumption, such
DD
, increases as V
IO0_0, IO0_2, IO0_3 configured as outputs.
IO0_1, IO0_4, IO0_5 configured as inputs.
IO0_6, IO0_7, and IO1_0 to IO1_7 configured as inputs.
Device address configured as 0100 000xb for this example.
CONTROLLER
I
MASTER
is about 1.2 V less than V
GND
V
DD
DD
When the I/Os are Used to Control
SCL
SDA
INT
I
becomes lower than V
DD
10 kW
through a resistor as shown in
10 kW
DD
. The supply current,
10 kW
DD
APPLICATION INFORMATION
Figure 11. Typical Application
.
AD2
AD1
AD0
INT
SCL
SDA
PCA9535E
http://onsemi.com
V
V
DD
SS
IO0_0
IO0_1
IO0_2
IO0_3
IO0_4
IO0_5
IO0_6
IO0_7
IO1_0
IO1_1
IO1_2
IO1_3
IO1_4
IO1_5
IO1_6
IO1_7
13
each 8−bit port is read independently, the interrupt caused by
Port 0 will not be cleared by a read of Port 1 or the other way
around.
Remark: 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.
pin voltages be greater than or equal to V
is off. This would minimize current consumption. Figure 12
shows a high value resistor in parallel with the LED.
Figure 13 shows V
at least 1.2 V. Both of these methods maintain the I/O V
or above V
consumption when the LED is off.
the PCA9535EC I/O pins are open−drain.
This concern does not occur for the PCA9535EC because
2 kW
NUMERIC
KEYPAD
10 DIGIT
DD
and prevents additional supply current
100 kW
(x3)
DD
less than the LED supply voltage by
ENABLE
INT
RESET
ALARM
(e.g., alarm system)
(e.g., temp sensor)
A
B
SUB−SYSTEM 1
SUB−SYSTEM 2
SUB−SYSTEM 3
(e.g., counter)
DD
controlled
switch
(e.g., 7SB or FST)
when the LED
V
DD
I
at