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NXP Semiconductors PCA9539BSHP
- Part No.:
- PCA9539BSHP
- Manufacturer:
- NXP Semiconductors
- Category:
- I/O Expanders
- Package:
- 24-VFQFN Exposed Pad
- Datasheet:
-
PCA9539BSHP.pdf
- Description:
- IC XPNDR 400KHZ I2C 24HVQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,507
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Product details
Overview
PCA9539BSHP from NXP Semiconductors is a 24-pin HVQFN-packaged 16-bit I²C/SMBus GPIO expander with active-low interrupt and hardware reset, operating from 2.3 V to 5.5 V, featuring 5 V-tolerant I/Os and polarity inversion registers. It serves as a low-power I/O extension solution in embedded control systems requiring remote sensor monitoring, LED driving, and push-button interfacing.
For engineers reviewing the PCA9539BSHP datasheet, PCA9539BSHP pinout, PCA9539BSHP application, or PCA9539BSHP equivalent, this page delivers verified technical context, validated pin functions, confirmed register-level behavior, and real-world use-case implementation guidance for industrial and consumer I²C-bus expansion designs.
Technical Context
The PCA9539BSHP implements two independent 8-bit I/O ports (Port 0 and Port 1), each with configurable direction via dedicated configuration registers (defaulting to input at power-on reset). Its interrupt output activates only on state changes of input-configured pins and clears upon reading the corresponding input port register.
It uses a fixed 7-bit I²C address (11101xx) determined by A0/A1 pins, supports standard/fast-mode I²C up to 400 kHz, and includes noise filtering on SCL/SDA inputs. The RESET pin performs full register + state machine reset in PCA9539 variants - matching PCA9539BSHP's behavior per ordering code and datasheet revision.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| I/O Count | 16 bidirectional GPIOs grouped as two 8-bit ports (IO0_0–IO0_7, IO1_0–IO1_7) |
| Supply Voltage | 2.3 V to 5.5 V - enables direct interface with 3.3 V and 5 V microcontrollers without level shifting |
| I/O Tolerance | 5 V tolerant - allows safe connection to 5 V peripherals even when VDD = 3.3 V |
| Interrupt Output | Active-low open-drain INT - requires external pull-up; asserts when input pin state differs from input register value |
| Reset Function | Active-low RESET - triggers full register and I²C state machine reset, restoring default configuration (all I/Os as inputs) |
| I²C Speed | 0 Hz to 400 kHz - compatible with standard- and fast-mode I²C buses without timing constraints |
| ESD Rating | >2000 V HBM - ensures robustness during handling and board assembly |
Pinout & Package
HVQFN24 package (SOT616-1), 4 mm × 4 mm × 0.85 mm body, thermally enhanced exposed pad requiring PCB thermal vias and solder connection to ground for optimal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| INT (Pin 22) | Interrupt output | Open-drain signal indicating change in any input-configured I/O state; must be pulled up externally |
| A1 (Pin 23) | Address input | LSB of device address (11101A1A0); sets one of four possible I²C addresses on shared bus |
| RESET (Pin 24) | Hardware reset | Active-low input that resets all registers and I²C state machine to defaults; requires external pull-up to VDD |
| IO0_0–IO0_7 (Pins 1–8) | Port 0 I/O | Eight general-purpose pins individually configurable as input or output via Configuration Port 0 register |
| VSS (Pin 9) | Ground | Primary supply return; must be connected to system ground; exposed pad also tied to VSS |
| IO1_0–IO1_7 (Pins 10–17) | Port 1 I/O | Eight general-purpose pins individually configurable as input or output via Configuration Port 1 register |
| A0 (Pin 18) | Address input | LSB of device address (11101A1A0); selects among four I²C addresses with A1 |
| SCL (Pin 19) | I²C clock | Input-only serial clock line; includes internal noise filter for reliable operation in noisy environments |
| SDA (Pin 20) | I²C data | Open-drain bidirectional serial data line; includes internal noise filter and 5 V tolerance |
| VDD (Pin 21) | Power supply | Core supply input (2.3–5.5 V); powers logic and I/O circuitry; decoupling capacitor required near pin |
Key Features
| Feature | Design Value |
|---|---|
| Polarity inversion registers | Per-port 8-bit registers (Ports 0/1) allow software-defined active-HIGH or active-LOW interpretation of input states |
| No-glitch power-up | Internal power-on reset ensures all I/Os default to high-impedance inputs before firmware initialization |
| Low standby current | Reduces system power consumption in battery-operated applications where I/Os are held LOW |
| Configurable I²C address | A0/A1 pins enable up to four PCA9539BSHP devices on same I²C bus without address conflict |
| Latch-up immunity | Exceeds JEDEC JESD78 (≥100 mA), ensuring reliability under transient overvoltage conditions |
Applications
| Industrial Control Panel Interface | Smart Home Sensor Hub |
|---|---|
Use Scenario: Expanding MCU GPIO count to manage 16 discrete signals including push buttons, status LEDs, and relay controls on a factory HMI panel. IC Role / Device Role / Timing Role: I²C slave GPIO expander providing synchronized input sampling and output drive capability with interrupt-driven button detection. Use Value: Reduces host MCU pin count burden while enabling responsive, low-latency user interaction via INT-triggered polling instead of continuous bus scanning. | Use Scenario: Centralized aggregation of temperature, motion, and door/window sensor inputs across multiple rooms in a residential automation gateway. IC Role / Device Role / Timing Role: Low-power I/O hub translating analog/digital sensor events into I²C-readable status bits with polarity inversion support for mixed-signal sensor logic levels. Use Value: Enables single I²C transaction to read all 16 sensor states; INT pin alerts host only when change occurs, minimizing background polling overhead. |
| LED Matrix Driver Support | ACPI Power Management Subsystem |
Use Scenario: Driving 16-channel LED indicators in medical equipment where brightness consistency and low quiescent current are critical. IC Role / Device Role / Timing Role: Constant-current-capable GPIO expander configured as current-sinking outputs with programmable polarity inversion for common-anode LED arrays. Use Value: Eliminates need for external transistor arrays; 5 V-tolerant I/Os simplify interface to higher-voltage LED supplies while maintaining 3.3 V MCU compatibility. | Use Scenario: Managing power sequencing signals, thermal shutdown flags, and fan speed control lines in laptop or embedded PC power management IC subsystems. IC Role / Device Role / Timing Role: ACPI-compliant I/O extension device providing standardized wake-event signaling (via INT) and hardware reset coordination (via RESET) with host EC or PMIC. Use Value: Supports OS-level suspend/resume transitions through reliable interrupt assertion and deterministic register reset behavior on power rail fluctuations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar GPIO expander applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCA9555BS | Includes internal 100 kΩ I/O pull-up resistors; otherwise identical register map and pinout | Higher quiescent current when I/Os driven LOW; less suitable for ultra-low-power battery systems | Select PCA9539BSHP when minimizing standby current is critical; choose PCA9555BS if internal pull-ups simplify BOM and layout |
| TCA9539PWR | TI variant with identical 16-bit I/O, interrupt, reset, and HVQFN24 package; supports same voltage range and I²C speed | Minor register bit definitions differ in polarity inversion behavior; requires firmware validation for drop-in replacement | Use TCA9539PWR only after verifying interrupt clearing sequence and polarity register compatibility in target firmware |
Compared with PCA9555BS and TCA9539PWR, the PCA9539BSHP offers the lowest standby current due to absence of internal pull-ups, making it optimal for energy-sensitive designs - while retaining full functional equivalence for most I²C GPIO expansion use cases.
Availability
PCA9539BSHP is available at Aetrix Electronics and suitable for industrial control panels, smart home sensor hubs, LED matrix interfaces, and ACPI power management subsystems requiring stable component supply and long-term production continuity.
Supply support for PCA9539BSHP 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 company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.
The PCA9539 product line delivers scalable, low-power I²C GPIO expansion for resource-constrained embedded systems - designed specifically to reduce MCU pin count pressure while maintaining robust interrupt-driven responsiveness and industrial-grade reliability.
FAQ
What is the function of the RESET pin on the PCA9539BSHP?
The RESET pin on the PCA9539BSHP is an active-low hardware input that triggers a full reset of all internal registers and the I²C-bus state machine, restoring default values (all I/Os as inputs, output registers = 0xFF, configuration registers = 0xFF). It requires an external pull-up resistor to VDD and must be held LOW for minimum tw(rst) to initiate reset. This behavior matches the PCA9539 (not PCA9539R) variant specified in the PCA9539BSHP ordering code.
Does the PCA9539BSHP support 5 V logic levels on its I/O pins?
Yes, the PCA9539BSHP features 5 V-tolerant I/O pins, meaning it can safely accept input voltages up to 5.5 V regardless of whether VDD is 2.3 V, 3.3 V, or 5.5 V. This allows direct interfacing with 5 V sensors, switches, or LEDs without external level-shifting circuitry - a key design advantage confirmed in Section 2 Features and Benefits of the datasheet.
How does the interrupt output (INT) behave on the PCA9539BSHP?
The INT pin on the PCA9539BSHP is an active-low open-drain output that asserts when any I/O pin configured as an input changes state relative to its corresponding bit in the input port register. It de-asserts automatically upon reading the relevant input port register (Port 0 or Port 1), and cannot be triggered by output-configured pins. This behavior is explicitly defined in Section 6.6.3 of the PCA9539; PCA9539R datasheet.
What package type is used for the PCA9539BSHP?
The PCA9539BSHP uses the HVQFN24 package (SOT616-1): a 4 mm × 4 mm × 0.85 mm thermally enhanced quad flat no-lead package with 24 terminals and an exposed center pad. Per datasheet Section 3.1, Pin 1 is located in Quadrant 2, and the exposed pad must be soldered to a grounded thermal pad on the PCB with thermal vias for proper electrical and thermal performance.
Can the PCA9539BSHP operate with a 3.3 V microcontroller?
Yes, the PCA9539BSHP operates across a supply range of 2.3 V to 5.5 V, making it fully compatible with 3.3 V microcontrollers. Its I²C interface (SCL/SDA) includes noise filters and supports standard/fast-mode speeds up to 400 kHz. Additionally, its 5 V-tolerant I/Os allow connection to higher-voltage peripherals while powered from 3.3 V - a capability verified in Table 2 and Section 2 of the official NXP datasheet.
PCA9539BSHP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 24-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Number of I/O:
- 16
- Interface:
- I2C
- Interrupt Output:
- Yes
- Features:
- POR
- Output Type:
- Open Drain
- Current - Output Source/Sink:
- 50mA
- 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:
- 24-HVQFN (4x4)
PCA9539BSHP FAQ
1.How can I place an order for PCA9539BSHP through Aetrix?
Please submit a Request for Quotation (RFQ) for PCA9539BSHP 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 PCA9539BSHP reliable?
The price and inventory of PCA9539BSHP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCA9539BSHP is usually 5 days.
3.What payment methods are accepted for PCA9539BSHP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCA9539BSHP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCA9539BSHP?
PCA9539BSHP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCA9539BSHP 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 PCA9539BSHP?
For technical support, including PCA9539BSHP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCA9539BSHP requirements.
6.How does Aetrix verify that PCA9539BSHP is sourced from the original manufacturer or authorized distributors?
All PCA9539BSHP 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 PCA9539BSHP meets industry standards.
7.What is the process for return or replacement of PCA9539BSHP?
All PCA9539BSHP units undergo pre-shipment inspection (PSI). If there is an issue with PCA9539BSHP, 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 PCA9539BSHP part is unused and in its original packaging.
Return procedure for PCA9539BSHP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
PCA9539BSHP Tags
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TCA9535RTWR
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FXL6408UMX
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PCF8574ADWR
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PCF8574APWR
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TCA9555PWR
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TCA9554PWR
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TCA9554APWR
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TCA9539PWR
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TCA9534PWR
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TCA9555RTWR
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TCA9535PWR
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