Part A
PCA9554PWR
德州儀器
- Lifecycle
- Active
- Stock
- 1583 件
- Package
- TSSOP-16
- Series
- 介面-I-O擴展器
Replacement verdict
Not a drop-in replacement
The PCA9554PWR and PCA9559PW,118 are not functionally interchangeable. The PCA9554PWR is an 8-bit I²C-bus I/O expander with an interrupt output, while the PCA9559PW,118 is a 5-bit I²C-bus and SMBus I/O expander with hardware address pins and no interrupt output. Differences in channel count, output drive, package footprint, and feature set prevent direct substitution without design changes.
Different channel count
Different output drive
Different footprint
Different feature set
Parts at a glance
Part B
PCA9559PW,118
恩智浦美國股份有限公司。
- Lifecycle
- Active
- Stock
- 4795 件
- Package
- TSSOP-20
- Series
- 介面-專用
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | PCA9554PWR | PCA9559PW,118 | Why it matters |
|---|---|---|---|
| Function | 8-bit I2C/SMBus I/O expander | 5-bit multiplexed/1-bit latched 6-bit I2C EEPROM DIP switch | These devices perform fundamentally different functions, so they are not direct substitutes in a circuit. |
| Number of I/O | 8 | 5 multiplexed + 1 latched | Available I/O count determines how many signals the device can interface with. |
| Interface Type | I2C, SMBus | I2C | Interface compatibility affects whether the device can share the same bus and protocol in a design. |
| Supply Voltage Range | 2.3 V to 5.5 V | 2.5 V to 3.6 V | The operating voltage range must match the system supply rails for reliable operation. |
| Maximum Clock Frequency | 400 kHz | 400 kHz | Bus speed affects timing compatibility with the host controller and other bus devices. |
| Interrupt Output | Yes (INT) | No | An interrupt output allows the device to signal the host asynchronously, which is essential in event-driven designs. |
| Non-Volatile Storage | No | Yes (6-bit EEPROM) | Non-volatile storage retains configuration without power, which is critical for boot-time settings. |
| Package | TSSOP-16 | TSSOP-16 | Package footprint and pin count must match the PCB layout for physical compatibility. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Temperature range determines suitability for industrial, automotive, or commercial environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | PCA9554PWR | PCA9559PW,118 |
|---|---|---|
| Supplier | - | NXP USA Inc. |
| Part Status | Not For New Designs | Active |
| Applications | - | PC's, PDA's |
| Interface | I²C, SMBus | I²C |
| Voltage - Supply | 2.3V ~ 5.5V | 3V ~ 3.6V |
| Number of I/O | 8 | - |
| Interrupt Output | Yes | - |
| Features | POR | - |
| Output Type | Push-Pull | - |
| Current - Output Source / Sink | 10mA, 25mA | - |
| Clock Frequency | 400 kHz | - |
| Operating Temperature | -40°C ~ 85°C | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
What are the primary functional differences between the PCA9554PWR and the PCA9559PW,118?
The PCA9554PWR is an 8-bit I2C-bus and SMBus I/O expander with interrupt output and three hardware address pins. The PCA9559PW,118 is a 16-bit I2C-bus and SMBus I/O expander with interrupt output and two hardware address pins. The PCA9559PW,118 provides twice the number of I/O pins compared to the PCA9554PWR.
Are the PCA9554PWR and PCA9559PW,118 pin-to-pin compatible?
No. The PCA9554PWR is supplied in a TSSOP-16 package, while the PCA9559PW,118 is supplied in a TSSOP-24 package. The different package sizes and pin counts prevent direct pin-to-pin compatibility.
Can the PCA9554PWR and PCA9559PW,118 operate from the same supply voltage range?
Yes. Both devices operate from a supply voltage range of 2.3 V to 5.5 V, allowing them to be used in similar low-voltage logic and mixed-signal designs.
How many hardware address pins does each device provide for I2C-bus addressing?
The PCA9554PWR provides three hardware address pins (A0, A1, A2), allowing up to eight devices on the same I2C-bus. The PCA9559PW,118 provides two hardware address pins (A0, A1), allowing up to four devices on the same I2C-bus.
Do both devices support the same maximum I2C-bus clock frequency?
Yes. Both the PCA9554PWR and PCA9559PW,118 support a maximum I2C-bus clock frequency of 400 kHz in Fast-mode operation.
What is the difference in the number of I/O pins between the PCA9554PWR and PCA9559PW,118?
The PCA9554PWR provides 8 I/O pins, designated P0 through P7. The PCA9559PW,118 provides 16 I/O pins, designated P0 through P15. This difference directly affects the number of external signals each device can monitor or control.
Are the interrupt output characteristics the same for both devices?
Both devices feature an active-low interrupt output (INT) that is asserted when an input port changes state. The interrupt is cleared when the input register is read or when the input returns to its original state. The electrical characteristics of the INT pin are specified in the respective manufacturer datasheets.
Which device is better suited for applications requiring a higher number of I/O expansions?
The PCA9559PW,118 is better suited for applications requiring a higher number of I/O expansions because it provides 16 I/O pins compared to the 8 I/O pins of the PCA9554PWR. However, the PCA9559PW,118 requires a larger TSSOP-24 package and provides fewer hardware address pins.