PCA9555AHF,128 NXP Semiconductors, PCA9555AHF,128 Datasheet - Page 14

• Manufacturer Part Number: PCA9555AHF,128
• Description: Interface - I/O Expanders
• Manufacturer: NXP Semiconductors

Specifications of PCA9555AHF,128

• Rohs: yes
• Maximum Operating Frequency: 100 kHz
• Operating Supply Voltage: 1.65 V to 5.5 V
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: HWQFN-24
• Operating Current: 160 mA
• Output Current: 25 mA
• Power Dissipation: 200 mW
• Product Type: I/O Expanders

NXP Semiconductors
8. Application design-in information
PCA9555A
Product data sheet
Fig 12. Typical application
(3.3 V)
(1) External resistors are required for inputs (on P port) that may float. Also, internal pull-up may be used to eliminate external
V
DD
Device address configured as 0100 000X for this example.
P0_0, P0_2, P0_3 configured as outputs.
P0_1, P0_4, P0_5 configured as inputs.
P0_6, P0_7 and (P1_0 to P1_7) configured as inputs.
components. If a driver to an input will never let the input float, a resistor is not needed. If an output in the P port is configured
as a push-pull output there is no need for external pull-up resistors. If an output in the P port is configured as an open-drain
output, external pull-up resistors are required.
CONTROLLER
MASTER
V
V
DD
SS
8.1 Minimizing I
SDA
SCL
INT
When the I/Os are used to control LEDs, they are normally connected to V
resistor as shown in
V
than V
Designs needing to minimize current consumption, such as battery power applications,
should consider maintaining the I/O pins greater than or equal to V
Figure 13
than the LED supply voltage by at least 1.2 V. Both of these methods maintain the I/O V
at or above V
I
is about 1.2 V less than V
10 kΩ
DD
.
shows a high value resistor in parallel with the LED.
10 kΩ
DD
DD
All information provided in this document is subject to legal disclaimers.
and prevents additional supply current consumption when the LED is off.
10 kΩ
Low-voltage 16-bit I
when the I/Os are used to control LEDs
Figure
Rev. 1 — 11 September 2012
SCL
SDA
INT
A2
A1
A0
PCA9555A
12. Since the LED acts as a diode, when the LED is off the I/O
V
V
DD
DD
SS
. The supply current, I
P0_0
P0_1
P0_2
P0_3
P0_4
P0_5
P0_6
P0_7
P1_0
P1_1
P1_2
P1_3
P1_4
P1_5
P1_6
P1_7
2
C-bus I/O port with interrupt and weak pull-up
2 kΩ
NUMERIC
10 DIGIT
KEYPAD
100 kΩ
(×3)
DD
, increases as V
enable
Figure 14
DD
INT
RESET
(e.g., alarm system)
ALARM
SUB-SYSTEM 1
(e.g., temp sensor)
SUB-SYSTEM 3
PCA9555A
A
B
SUB-SYSTEM 2
(e.g., counter)
when the LED is off.
© NXP B.V. 2012. All rights reserved.
I
controlled
switch
(e.g., CBT device)
becomes lower
shows V
DD
through a
002aaf847
(1)
(1)
V
DD
DD
14 of 39
less
I