pca9538d NXP Semiconductors, pca9538d Datasheet - Page 8

• Manufacturer Part Number: pca9538d
• Description: 8-bit I2c And Smbus Low Power I/o Port With Interrupt And Reset
• Manufacturer: NXP Semiconductors

Philips Semiconductors
TYPICAL APPLICATION
Minimizing I
When the I/Os are used to control LEDs, they are normally connected to V
diode, when the LED is off the I/O V
specified as I
Designs needing to minimize current consumption, such as battery power applications, should consider maintaining the I/O pins greater than or
equal to V
voltage by at least 1.2 V. Both of these methods maintain the I/O V
the LED is off.
2006 Sep 21
8-bit I
I/O port with interrupt and reset
(5 V)
V
Figure 11. High value resistor in parallel with the LED
DD
NOTE: Device address configured as 1110000 for this example
DD
2
C-bus and SMBus low power
CONTROLLER
I/O
I/O
I/O
when the LED is off. Figure 11 shows a high value resistor in parallel with the LED. Figure 12 shows V
DD
0
1
06
MASTER
, I/O
, I/O
DD
, I/O
in the DC characteristics table.
2
4
, I/O
, I/O
7
GND
when the I/O is used to control LEDs
V
, are not used and need 100 k pull-up resistors to protect them from floating.
DD
V
LEDx
DD
3
5
, configured as outputs
, configured as inputs
IRESET
INT
SDA
SCL
10 k
LED
IN
is about 1.2 V less than V
10 k
100 k
V
DD
10 k
Figure 10. Typical application
SW02086
10 k
DD
IN
. The supply current , I
at or above V
8
A1
A0
SDA
INT
IRESET
SCL
DD
PCA9538
V
through a resistor as shown in Figure 10. Since the LED acts as a
DD
V
SS
DD
Figure 12. Device supplied by a lower voltage
and prevents additional supply current consumption when
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
0
1
2
3
4
5
6
7
DD
, increases as V
2 k
V
3.3 V
DD
LEDx
IN
becomes lower than V
100 k
( 3)
ENABLE
LED
DD
5 V
less than the LED supply
A
B
(e.g. temp sensor)
INT
RESET
ALARM
SUBSYSTEM 1
SUBSYSTEM 3
SUBSYSTEM 2
PCA9538
(e.g. counter)
(e.g. alarm
Product data sheet
system)
Controlled Switch
(e.g. CBT device)
SW02180
DD
V
SW02087
DD
and is