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NXP Semiconductors PCA9539BS,115
- Part No.:
- PCA9539BS,115
- Manufacturer:
- NXP Semiconductors
- Category:
- I/O Expanders
- Package:
- 24-VFQFN Exposed Pad
- Datasheet:
-
PCA9539BS,115.pdf
- Description:
- IC XPND 400KHZ I2C SMBUS 24HVQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,396
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Product details
Overview
PCA9539BS,115 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, supporting up to 400 kHz clock frequency, and featuring 5 V tolerant I/Os for mixed-voltage system interfacing - used in industrial control panels requiring remote sensor/LED/fan I/O expansion.
For engineers reviewing the PCA9539BS,115 datasheet, PCA9539BS,115 pinout, PCA9539BS,115 application, or PCA9539BS,115 equivalent, this device delivers deterministic interrupt-driven input monitoring, polarity-invertible register reads, low-standby-current I/O control, and dual-port configuration flexibility without internal pull-ups - critical for battery-sensitive and noise-prone embedded interfaces.
Technical Context
The PCA9539BS,115 implements two independent 8-bit I/O ports (Port 0 and Port 1), each with dedicated configuration, input, output, and polarity inversion registers - enabling per-pin direction control and active-HIGH/LOW input interpretation. Its interrupt logic triggers only on state changes of input-configured pins and clears upon reading the corresponding input port register.
It uses a fixed I²C target address (11101xxX) set 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, distinguishing it from the PCA9539R's state-machine-only reset behavior.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| I/O Count | 16 bidirectional GPIOs, split across two 8-bit ports with independent configuration registers |
| Supply Voltage | 2.3 V to 5.5 V - enables direct interface with 3.3 V and 5 V microcontrollers without level shifters |
| I²C Speed | 0 Hz to 400 kHz - compatible with standard and fast-mode I²C buses; no high-speed mode support |
| I/O Tolerance | 5 V tolerant - allows safe connection to 5 V peripherals while powered from 3.3 V supply |
| Interrupt Output | Active-low open-drain INT - asserts when any input pin state differs from its input port register value |
| Reset Function | Active-low RESET pin resets registers and I²C state machine - required pull-up to VDD for proper operation |
| ESD Rating | >2000 V HBM - robust against handling-induced electrostatic discharge during assembly |
Pinout & Package
HVQFN24 package (SOT616-1), 4 × 4 × 0.85 mm body, thermally enhanced with exposed center pad requiring PCB thermal vias and solder connection to ground for optimal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IO0_0–IO0_7 | Port 0 I/O pins | Individually configurable as input or output; default to high-impedance inputs at power-on reset |
| IO1_0–IO1_7 | Port 1 I/O pins | Independent 8-bit port with identical register mapping and polarity inversion capability |
| A0, A1 | I²C address inputs | Set LSBs of 7-bit slave address (11101xxX); enable up to four devices on same bus |
| RESET | Active-low hardware reset | Resets all registers and I²C state machine; requires external pull-up to VDD |
| INT | Open-drain interrupt output | Asserts LOW when input pin state changes; cleared by reading corresponding input port register |
| SCL / SDA | I²C bus interface | Compatible with SMBus timing; includes internal noise filters on both lines |
| VDD / VSS | Power and ground | VSS connects to both pin 9 and exposed thermal pad; pad must be soldered to ground plane |
Key Features
| Feature | Design Value |
|---|---|
| 16-bit GPIO expansion | Two independent 8-bit ports with separate configuration, input, output, and polarity registers - enables asymmetric I/O setup per subsystem |
| No internal pull-up resistors | Eliminates standby current path when I/Os are held LOW - reduces quiescent power vs. PCA9555 in battery-critical applications |
| Polarity inversion register | Per-bit inversion of input port data - avoids software-level bit-flipping for active-LOW sensors or switches |
| Interrupt-on-change logic | Hardware-generated INT signal triggered only by input pin transitions - offloads polling burden from host controller |
| Power-on reset + hardware RESET | Guaranteed known initial state at power-up; external RESET allows runtime reinitialization without cycling VDD |
Applications
| Industrial Control Panel | Smart HVAC Controller |
|---|---|
|
Use Scenario: Remote monitoring of push buttons, temperature sensors, and status LEDs across distributed cabinet zones. IC Role / Device Role / Timing Role: I/O expander providing interrupt-driven input capture and LED drive outputs via I²C, reducing MCU GPIO load. Use Value: Enables single I²C bus to manage 16 discrete signals with deterministic edge-triggered notification - eliminating scan-loop latency. |
Use Scenario: Centralized fan speed control, airflow sensor readout, and alarm indicator management in wall-mounted HVAC units. IC Role / Device Role / Timing Role: GPIO hub interfacing 5 V analog sensors and 3.3 V MCU; uses polarity inversion for direct active-LOW switch integration. Use Value: 5 V tolerant I/Os eliminate external level shifters; low standby current extends battery backup runtime during power loss. |
| Medical Device Front Panel | POS Terminal Keypad Interface |
|
Use Scenario: Safe, ESD-hardened interface for membrane keypads and status indicators in Class II medical equipment. IC Role / Device Role / Timing Role: Isolated I/O extension with >2000 V HBM protection; INT pin alerts host MCU only on actual keypress events. Use Value: Reduces firmware polling overhead and improves ESD resilience over direct MCU GPIO routing - meeting IEC 60601-1 requirements. |
Use Scenario: Scanning 10-digit numeric keypad and driving bi-color status LEDs in retail point-of-sale terminals. IC Role / Device Role / Timing Role: Configurable port 0 as keypad row drivers, port 1 as column inputs with interrupt-on-change detection. Use Value: Hardware-accelerated key detection via INT eliminates continuous scanning; 400 kHz I²C supports rapid UI response under heavy bus load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar GPIO expansion applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCA9539D,112 | SO24 package (7.5 mm width), same electrical specs and register map as PCA9539BS,115 | Preferred for through-hole prototyping or legacy board designs with SOIC footprints | Select when board layout requires larger pitch, manual soldering, or thermal mass tolerance over HVQFN |
| PCA9539PW,112 | TSSOP24 package (4.4 mm width), identical functionality and timing, same 2.3–5.5 V range | Suitable for space-constrained PCBs where HVQFN reflow is not available but finer pitch than SO24 is acceptable | Choose for mid-density layouts needing better thermal performance than SO24 but simpler assembly than HVQFN |
Compared with PCA9539D,112 and PCA9539PW,112, the PCA9539BS,115 offers superior thermal dissipation and smallest footprint via HVQFN24, making it optimal for high-reliability, high-density industrial modules where board area and junction temperature are critical.
Availability
PCA9539BS,115 is available at Aetrix Electronics and suitable for industrial control panels, smart HVAC systems, medical front panels, and POS terminal designs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for PCA9539BS,115 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 I²C ecosystem IP and low-power interface ICs.
The PCA9539 product line was developed to extend NXP's I²C-bus I/O expander family with ultra-low-power operation and interrupt-driven responsiveness - targeting resource-constrained embedded systems needing reliable peripheral expansion.
FAQ
What is the function of the RESET pin on the PCA9539BS,115?
The RESET pin on the PCA9539BS,115 is an active-low input that fully resets the device's internal registers and I²C-bus state machine to their power-on defaults. It requires an external pull-up resistor to VDD and must be held LOW for a minimum duration (tw(rst)) to initiate reset. Unlike the PCA9539R variant, the PCA9539BS,115 resets both registers and state logic - ensuring deterministic startup behavior in safety-critical applications.
Does the PCA9539BS,115 support 5 V logic levels on its I/O pins?
Yes, the PCA9539BS,115 features 5 V tolerant I/Os, allowing its GPIO pins to safely interface with 5 V peripherals even when powered from a 2.3 V to 5.5 V supply. This eliminates the need for external level-shifting circuitry in mixed-voltage systems - a key advantage over non-tolerant expanders like the MCP23017 when connecting to legacy 5 V sensors or indicators.
How does the interrupt output (INT) behave on the PCA9539BS,115?
The INT pin on the PCA9539BS,115 is an open-drain output that asserts LOW when any input-configured I/O pin changes state relative to its stored value in the input port register. The interrupt remains active until the corresponding input port register (Port 0 or Port 1) is read - meaning reading Port 0 clears only Port 0 interrupts, not Port 1. This ensures precise source identification in multi-sensor systems.
What is the I²C address range supported by the PCA9539BS,115?
The PCA9539BS,115 uses a fixed 7-bit I²C address prefix of 11101xx, where the two LSBs (xx) are set by the A0 and A1 pins - enabling four unique addresses (0x74, 0x75, 0x76, 0x77) on the same bus. No software-configurable address bits exist; address selection is strictly hardware-based via these two pins, simplifying multi-device arbitration in compact designs.
Can the PCA9539BS,115 drive LEDs directly?
Yes, the PCA9539BS,115 can drive LEDs directly using its I/O pins configured as outputs, but design caution is required: since it lacks internal pull-up resistors, sinking current (LED anode to VDD, cathode to I/O) is preferred. For lowest IDD in battery-powered use, maintain I/O voltage ≥ VDD when LED is OFF - achievable via parallel high-value resistors or external VDD offset, as detailed in NXP Application Note AN10364.
PCA9539BS,115 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, 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:
- 24-HVQFN (4x4)
PCA9539BS,115 FAQ
1.How can I place an order for PCA9539BS,115 through Aetrix?
Please submit a Request for Quotation (RFQ) for PCA9539BS,115 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 PCA9539BS,115 reliable?
The price and inventory of PCA9539BS,115 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCA9539BS,115 is usually 5 days.
3.What payment methods are accepted for PCA9539BS,115?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCA9539BS,115 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCA9539BS,115?
PCA9539BS,115 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCA9539BS,115 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 PCA9539BS,115?
For technical support, including PCA9539BS,115 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCA9539BS,115 requirements.
6.How does Aetrix verify that PCA9539BS,115 is sourced from the original manufacturer or authorized distributors?
All PCA9539BS,115 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 PCA9539BS,115 meets industry standards.
7.What is the process for return or replacement of PCA9539BS,115?
All PCA9539BS,115 units undergo pre-shipment inspection (PSI). If there is an issue with PCA9539BS,115, 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 PCA9539BS,115 part is unused and in its original packaging.
Return procedure for PCA9539BS,115:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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