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NXP Semiconductors PCA9538PW,118
- Part No.:
- PCA9538PW,118
- Manufacturer:
- NXP Semiconductors
- Category:
- I/O Expanders
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
PCA9538PW,118.pdf
- Description:
- IC XPND 400KHZ I2C SMBUS 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,655
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Product details
Overview
PCA9538PW,118 from NXP Semiconductors is an 8-bit I²C-bus/SMBus GPIO expander with interrupt and active-low reset, housed in a TSSOP16 package. It provides configurable input/output pins, polarity inversion, and low-power standby operation (0.25 µA typical), enabling expansion of microcontroller I/O for sensor interfaces, LED control, and push-button monitoring in industrial and embedded systems.
For engineers reviewing the PCA9538PW,118 datasheet, PCA9538PW,118 pinout, PCA9538PW,118 application, or PCA9538PW,118 equivalent, this device delivers verified I²C address flexibility (4 options via A0/A1), 5 V-tolerant I/Os, 0–400 kHz clock support, and deterministic reset/interrupt timing - critical for reliable system-level I/O management in space-constrained designs.
Technical Context
The PCA9538PW,118 implements a register-mapped I²C slave interface with four dedicated 8-bit registers: Input Port (read-only), Output Port (read/write), Polarity Inversion (read/write), and Configuration (read/write). Its internal state machine initializes all I/Os as inputs on power-on reset or active-low RESET assertion, ensuring predictable startup behavior without external initialization firmware.
Interrupt generation is edge-triggered and asynchronous: the open-drain INT output activates when any configured input pin's logic level differs from its corresponding Input Port register value. The INT signal deasserts only upon reading the Input Port register or when the pin returns to its prior state - enabling precise change-of-state detection without polling overhead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| I²C Clock Frequency | 0 Hz to 400 kHz - supports standard- and fast-mode I²C buses without external clock conditioning. |
| Supply Voltage Range | 2.3 V to 5.5 V - interoperable with 3.3 V and 5 V host controllers and peripheral logic families. |
| Standby Current | 0.25 µA typical at 5.5 V - enables battery-backed or energy-sensitive applications with minimal quiescent drain. |
| I/O Voltage Tolerance | 5.5 V max on I/O pins - allows safe interfacing with 5 V sensors or actuators even when VDD = 3.3 V. |
| Interrupt Output | Open-drain, active-low - simplifies wired-OR interrupt bus sharing across multiple expanders or peripherals. |
| Reset Input | Active-low, asynchronous - permits system-level reset coordination without cycling VDD or disrupting I²C bus traffic. |
| ESD Protection | 2000 V HBM, 1000 V CDM - meets industrial-grade robustness requirements for board-level handling and field operation. |
Pinout & Package
TSSOP16 package (SOT403-1), 4.4 mm body width, 0.65 mm lead pitch, surface-mount compatible with standard reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0 | Hardware I²C address bit 0 | Configures LSB of 7-bit slave address (11100xx); enables up to four PCA9538 devices on same bus. |
| A1 | Hardware I²C address bit 1 | Configures MSB of address bits xx; combined with A0, selects one of four fixed addresses (1110000–1110011). |
| RESET | Active-low asynchronous reset | Forces all registers to default values and reinitializes I/O direction to input without power cycle. |
| IO0–IO7 | Configurable bidirectional I/O | Each pin independently set as input (high-Z) or output (push-pull) via Configuration register; defaults to input at reset. |
| INT | Open-drain interrupt output | Asserts low when input state changes differ from Input Port register; requires external pull-up resistor. |
| SCL/SDA | I²C serial clock/data lines | Compliant with I²C-bus and SMBus electrical specifications; includes noise filtering on both inputs. |
| VDD/VSS | Power supply and ground | VDD accepts 2.3–5.5 V; VSS must be connected to system ground; no internal regulator or LDO. |
Key Features
| Feature | Design Value |
|---|---|
| Polarity Inversion Register | Per-pin inversion of Input Port data enables direct logic-level matching to active-HIGH or active-LOW sensors without external inverters. |
| No Glitch on Power-Up | Internal power-on reset ensures all I/Os start in high-impedance input mode - prevents spurious outputs during boot. |
| Input Noise Filtering | Digital filtering on SCL/SDA pins suppresses pulses ≤50 ns, improving immunity to EMI in noisy industrial environments. |
| 5 V-Tolerant I/Os | Allows connection to 5 V peripherals while operating from 3.3 V VDD - eliminates level-shifter components in mixed-voltage systems. |
| Low Standby Current | 0.25 µA typical at 5.5 V with all I/Os as inputs - extends battery life in always-on monitoring nodes. |
Applications
| Industrial Sensor Interface | LED Status Panel Control |
|---|---|
|
Use Scenario: Monitoring temperature, humidity, and door-switch status in programmable logic controller (PLC) backplanes. IC Role / Device Role / Timing Role: I/O expander providing isolated, interrupt-driven input sampling for eight discrete sensors. Use Value: Reduces host MCU GPIO usage by 8 pins while enabling immediate notification of state changes via INT line. |
Use Scenario: Driving 8-channel status LEDs on a network switch front panel with brightness control via PWM from host. IC Role / Device Role / Timing Role: Output port buffer with 5 V-tolerant drive capability, supporting direct LED anode connection to 5 V rail. Use Value: Eliminates discrete transistors and current-limiting resistors per LED; simplifies PCB layout and BOM. |
| Push-Button Keypad Interface | Alarm System Input Aggregation |
|
Use Scenario: Scanning 8 mechanical push-buttons in a medical device user interface with debounce handled in firmware. IC Role / Device Role / Timing Role: Parallel input capture with interrupt-on-change to wake host MCU from low-power sleep mode. Use Value: Achieves <1 µA system standby current by disabling host I/O ports while retaining responsive button detection. |
Use Scenario: Consolidating intrusion detection signals from motion, glass-break, and door-contact sensors in a security panel. IC Role / Device Role / Timing Role: Fault-tolerant input aggregator with polarity inversion to normalize active-LOW alarm triggers. Use Value: Enables single-interrupt reporting of any alarm event without host polling, reducing firmware complexity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I²C GPIO expander applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCA9554PW,118 | Includes internal 100 kΩ I/O pull-up resistors; higher standby current (1.5 µA vs. 0.25 µA). | Better suited for open-collector sensor interfaces requiring weak pull-ups; less optimal for ultra-low-power battery use. | Select PCA9554PW,118 if internal pull-ups eliminate need for external resistors and power budget allows ~6× higher standby draw. |
| TCA6408APWR | TI part with identical 8-bit I/O, interrupt, and reset; wider VDD range (1.65–5.5 V); no AEC-Q100 variant. | Supports 1.8 V host systems where PCA9538PW,118 minimum is 2.3 V; lacks automotive qualification option. | Choose TCA6408APWR for 1.8 V designs or when TI supply chain preference applies; verify INT timing compatibility. |
Compared with PCA9538PW,118, the PCA9554PW,118 trades lower design component count for higher quiescent power, while the TCA6408APWR extends voltage compatibility downward but omits automotive-grade qualification - making PCA9538PW,118 optimal for cost-sensitive, 2.3–5.5 V industrial applications requiring proven low-power operation.
Availability
PCA9538PW,118 is available at Aetrix Electronics and suitable for industrial automation, embedded sensor hubs, and LED control panels requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for PCA9538PW,118 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in interface and power management ICs.
The PCA9538 belongs to NXP's I²C-bus I/O expander product line, designed specifically to simplify GPIO expansion in resource-constrained embedded systems while maintaining robust bus communication and low-power operation.
FAQ
What is the maximum I²C clock frequency supported by PCA9538PW,118?
The PCA9538PW,118 supports I²C-bus operation up to 400 kHz (fast-mode), as confirmed in the dynamic characteristics table. This allows high-speed register access without compromising timing margins, and it remains fully compatible with standard-mode (100 kHz) controllers for backward integration.
Does PCA9538PW,118 require external pull-up resistors on SCL and SDA lines?
Yes, PCA9538PW,118 requires external pull-up resistors on both SCL and SDA lines to ensure proper I²C bus operation. The device does not include internal pull-ups on these lines, and the datasheet specifies typical values of 10 kΩ for 5 V systems and 2.2 kΩ for 3.3 V systems.
Can PCA9538PW,118 drive LEDs directly, and what current limits apply?
PCA9538PW,118 can sink up to 24 mA per I/O pin (at VDD = 4.5 V, VOL = 0.7 V) and source up to 85 mA total across all pins. For LED driving, configure pins as outputs and connect LEDs between VDD and the I/O - ensuring per-pin current stays within 25 mA and total sourced current remains ≤85 mA.
How does the RESET pin function on PCA9538PW,118, and what is the minimum pulse width?
The RESET pin on PCA9538PW,118 is active-low and asynchronous. Holding it low for ≥4 ns (tw(rst)) forces all registers to default values and reinitializes the I/O direction to input. The pin requires an external pull-up resistor to VDD if not actively driven, and release timing is specified as 400 ns (trst).
Is PCA9538PW,118 pin-compatible with PCA9538PW/Q900?
Yes, PCA9538PW,118 and PCA9538PW/Q900 share identical TSSOP16 pinout and footprint (SOT403-1), but differ in temperature rating and qualification: PCA9538PW,118 is rated for –40 °C to +85 °C, while PCA9538PW/Q900 is AEC-Q100 qualified for –40 °C to +125 °C operation.
PCA9538PW,118 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Number of I/O:
- 8
- Interface:
- I2C, SMBus
- Interrupt Output:
- Yes
- Features:
- POR
- Output Type:
- Push-Pull
- Current - Output Source/Sink:
- 10mA, 25mA
- Clock Frequency:
- 400 kHz
- Voltage - Supply:
- 2.3V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
PCA9538PW,118 FAQ
1.How can I place an order for PCA9538PW,118 through Aetrix?
Please submit a Request for Quotation (RFQ) for PCA9538PW,118 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for PCA9538PW,118 reliable?
The price and inventory of PCA9538PW,118 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCA9538PW,118 is usually 5 days.
3.What payment methods are accepted for PCA9538PW,118?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCA9538PW,118 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCA9538PW,118?
PCA9538PW,118 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCA9538PW,118 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for PCA9538PW,118?
For technical support, including PCA9538PW,118 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCA9538PW,118 requirements.
6.How does Aetrix verify that PCA9538PW,118 is sourced from the original manufacturer or authorized distributors?
All PCA9538PW,118 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that PCA9538PW,118 meets industry standards.
7.What is the process for return or replacement of PCA9538PW,118?
All PCA9538PW,118 units undergo pre-shipment inspection (PSI). If there is an issue with PCA9538PW,118, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The PCA9538PW,118 part is unused and in its original packaging.
Return procedure for PCA9538PW,118:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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