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NXP Semiconductors PCAL6408AEXX
- Part No.:
- PCAL6408AEXX
- Manufacturer:
- NXP Semiconductors
- Category:
- I/O Expanders
- Package:
- 16-XFBGA
- Datasheet:
-
PCAL6408AEXX.pdf
- Description:
- IC XPND 400KHZ I2C SMBUS 16XFBGA
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
PCAL6408AEXX from NXP Semiconductors is an 8-bit I²C-bus/SMBus I/O expander with bidirectional voltage-level translation, programmable pull-up/pull-down resistors, latchable inputs, and open-drain interrupt output. It operates across dual supply rails (VDD(I2C-bus): 1.65–5.5 V; VDD(P): 1.65–5.5 V), supports 400 kHz Fast-mode I²C, and delivers 25 mA sink capability per port pin for direct LED driving - used in battery-powered mobile sensor interfaces and mixed-voltage microcontroller peripheral expansion.
For engineers reviewing the PCAL6408AEXX datasheet, PCAL6408AEXX pinout, PCAL6408AEXX application, or PCAL6408AEXX equivalent, key selection criteria include dual-rail level-shifting capability, interrupt masking and status reporting, Agile I/O features (drive strength, input latching), and XFBGA16 package compatibility with 1.6 mm × 1.6 mm footprint and 0.5 mm height.
Technical Context
The PCAL6408AEXX implements a register-mapped I²C slave interface with dedicated Agile I/O control registers (e.g., 40h–46h, 4Fh) enabling per-pin configuration of drive strength, input latch enable, pull-up/pull-down selection (100 kΩ), and interrupt masking. Its internal power-on reset initializes all I/Os as inputs and masks interrupts by default to prevent spurious wakeups during board bring-up.
Voltage translation is achieved via VDD(I2C-bus)-referenced I²C interface logic and VDD(P)-referenced port drivers, supporting combinations including 1.8 V SCL/SDA with 3.3 V or 5 V Port P. Schmitt-trigger inputs on SCL/SDA provide noise immunity (Vhys = 0.18–0.5 V depending on VDD(I2C-bus)), and ESD protection meets 2000 V HBM and 1000 V CDM standards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| I²C Bus Speed | 400 kHz Fast-mode - enables high-speed host communication without timing margin compromise in compact embedded systems. |
| VDD(I2C-bus) Range | 1.65 V to 5.5 V - sets I²C interface logic level and defines voltage reference for bidirectional level translation to Port P. |
| VDD(P) Range | 1.65 V to 5.5 V - powers Port P drivers and determines output voltage swing and sink capability (25 mA max per pin). |
| Interrupt Output | Open-drain, active LOW - requires external pull-up; asserts when masked/unmasked input state change differs from Input Port register value. |
| Input Latch Function | Bit-wise enable via register 42h - holds interrupt-causing logic state until Input Port register is read, reducing host ISR latency for fast edge events. |
| Output Drive Strength | Four programmable levels (0.25× to 1× full drive) per pin via registers 40h/41h - optimizes rise/fall times in low-capacitance PCB traces. |
| ESD Protection | 2000 V HBM, 1000 V CDM - ensures robustness against handling and system-level electrostatic discharge in portable electronics. |
Pinout & Package
XFBGA16 package: 1.6 mm × 1.6 mm × 0.5 mm body, 16-ball land grid array, 0.4 mm pitch, exposed center pad (optional VSS or floating).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 | RESET | Active LOW asynchronous reset - initializes registers and I²C state machine without power cycle; requires pull-up to VDD(I2C-bus). |
| A2 | VDD(I2C-bus) | I²C interface supply - defines SCL/SDA logic levels and enables voltage translation to Port P. |
| A3 | VDD(P) | Port P supply - sets output voltage range, sink current capability (25 mA), and pull-up/pull-down resistor bias. |
| A4 | SCL | I²C serial clock - Schmitt-triggered input with 0.18–0.5 V hysteresis; requires pull-up to VDD(I2C-bus). |
| B1 | P0 | Programmable I/O port 0 - configurable as input (high-Z) or output (push-pull/open-drain); supports latching and polarity inversion. |
| B2 | ADDR | Hardware I²C address select - tied HIGH/LOW to set LSB of 7-bit slave address (0x20 or 0x21). |
| B3 | SDA | I²C serial data - bidirectional, Schmitt-triggered, requires pull-up to VDD(I2C-bus). |
| B4 | INT | Open-drain interrupt output - asserts LOW when unmasked input state change occurs; requires external pull-up. |
| C1 | P2 | Programmable I/O port 2 - identical functionality to P0; supports Agile I/O features including drive strength control. |
| C2 | P1 | Programmable I/O port 1 - bit-wise latchable input or push-pull/open-drain output; polarity invertible via register 02h. |
| C3 | P7 | Programmable I/O port 7 - supports 25 mA sink for LED drive; configured via Output Port (01h) and Configuration (03h) registers. |
| C4 | P6 | Programmable I/O port 6 - pull-up/pull-down enabled via register 43h/44h; 100 kΩ default resistor value. |
| D1 | P3 | Programmable I/O port 3 - interrupt mask controlled per-pin via register 45h; status readable in register 46h. |
| D2 | VSS | Ground reference - common return for both I²C interface and Port P circuits; center pad may be connected to VSS. |
| D3 | P4 | Programmable I/O port 4 - input latch enabled via register 42h bit L4; retains state until Input Port register is read. |
| D4 | P5 | Programmable I/O port 5 - output drive strength selected via register 40h/41h bits CC5[1:0]; reduces signal distortion on long traces. |
Key Features
| Feature | Design Value |
|---|---|
| Agile I/O Register Set | Eight extended control registers (40h–46h, 4Fh) enable per-pin drive strength, latch enable, pull-up/down selection, and interrupt masking - eliminating discrete logic and firmware overhead. |
| Power-Up Interrupt Masking | All eight interrupt mask bits default to 1 at power-on - prevents spurious INT assertion during system initialization and simplifies boot sequence design. |
| Programmable Pull-Up/Pull-Down | 100 kΩ resistors (±50%) selectable per pin via registers 43h/44h - replaces external components and supports floating, weak-pull, or strong-pull configurations. |
| Input Latch with Status Reporting | Latched input states persist until Input Port register read; interrupt source identified unambiguously via read-only status register (46h) - critical for reliable edge detection in real-time systems. |
| Dual-Rail Level Translation | VDD(I2C-bus) and VDD(P) independently set from 1.65 V to 5.5 V - enables seamless interfacing between 1.8 V microcontrollers and 5 V peripherals without external translators. |
| Low Standby Current | 1 µA typical quiescent current - extends battery life in always-on sensor nodes and portable devices where I/O expander remains powered during sleep modes. |
Applications
| Mobile Keypad Interface | Industrial Sensor Hub |
|---|---|
Use Scenario: Compact smartphone or wearable device requiring GPIO expansion for mechanical keypad scanning under tight PCB area constraints. IC Role / Device Role / Timing Role: I/O expander providing 8-bit parallel interface over I²C, with built-in Schmitt-trigger inputs to reject contact bounce noise on keypress signals. Use Value: Eliminates need for external debounce circuitry and discrete level shifters; 1.6 mm × 1.6 mm XFBGA16 package saves >60% board space versus TSSOP16 alternatives. |
Use Scenario: Programmable logic controller (PLC) module aggregating analog and digital sensor inputs across multiple voltage domains (e.g., 3.3 V MCU + 24 V field sensors). IC Role / Device Role / Timing Role: Voltage-translating I/O hub managing isolated digital inputs with interrupt-driven event notification to reduce polling overhead. Use Value: Dual-supply operation allows direct connection to 24 V optocoupler outputs via level-shifted P0–P7 pins; INT output triggers MCU ISR only on state change, cutting CPU load by ~90% vs. polling. |
| LED Backlight Driver | IoT Edge Node Expansion |
Use Scenario: Smart display backlight control in medical handhelds where each LED string requires independent on/off and brightness modulation. IC Role / Device Role / Timing Role: Constant-current sink driver using P0–P7 as 25 mA capable outputs, configured via I²C write to Output Port register (01h). Use Value: Direct LED drive eliminates external MOSFETs and current-limiting resistors; programmable drive strength (registers 40h/41h) minimizes EMI during PWM dimming transitions. |
Use Scenario: Battery-powered environmental monitor collecting temperature, humidity, and motion data while maintaining multi-year operational life. IC Role / Device Role / Timing Role: Low-power I/O expander enabling wake-on-event functionality via latched interrupt inputs connected to PIR and door sensors. Use Value: 1 µA standby current and interrupt masking prevent false wakeups; input latch (register 42h) captures transient motion pulses missed by shallow-sleep MCU polling cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I/O expansion applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCA6408APW | Lacks Agile I/O features: no input latching, no programmable drive strength, no interrupt status register; fixed push-pull outputs only. | Requires external debounce logic for noisy inputs; cannot support low-latency edge detection or mixed-voltage sensor hubs with latch requirements. | Select PCA6408APW only for cost-sensitive, static I/O expansion where advanced interrupt handling and voltage translation flexibility are unnecessary. |
| TCA6408APWR | TI part with identical 8-bit I²C I/O count and 1.65–5.5 V VDD range, but no input latch or programmable pull-up/pull-down; interrupt mask register present but no status register. | Supports basic interrupt-driven I/O but cannot retain input state across reads; lacks per-pin drive tuning for EMI-sensitive layouts. | Choose TCA6408APWR when migrating TI-based designs or when sourcing diversity is required, accepting trade-offs in debuggability and signal integrity control. |
Compared with PCA6408APW and TCA6408APWR, PCAL6408AEXX provides unique Agile I/O capabilities - specifically input latching with status reporting and per-pin drive strength control - making it the only option among the three that supports deterministic interrupt handling and optimized signal integrity in space-constrained, mixed-voltage embedded systems.
Availability
PCAL6408AEXX is available at Aetrix Electronics and suitable for battery-powered mobile interfaces, industrial sensor aggregation, LED backlight control, and IoT edge node expansion requiring stable component supply and long-term lifecycle support.
Supply support for PCAL6408AEXX 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 mixed-signal interface ICs and embedded processing.
The PCAL6408AEXX belongs to NXP's Agile I/O expander product line, designed specifically to simplify mixed-voltage peripheral interfacing and reduce bill-of-materials count in resource-constrained embedded systems.
FAQ
What is the package type and dimensions of PCAL6408AEXX?
The PCAL6408AEXX uses the XFBGA16 package: a 1.6 mm × 1.6 mm × 0.5 mm fine-pitch ball grid array with 16 solder balls arranged in a 4×4 grid and 0.4 mm pitch. The exposed center pad is optional and may be left floating or connected to VSS. This package was discontinued for new designs after November 2016; PCAL6408AEXX remains available for legacy support and existing production runs.
How does PCAL6408AEXX handle voltage level translation between I²C and Port P?
The PCAL6408AEXX achieves bidirectional level translation using two independent supplies: VDD(I2C-bus) sets the logic threshold for SCL/SDA (1.65–5.5 V), while VDD(P) powers the Port P drivers (1.65–5.5 V). This allows combinations such as 1.8 V microcontroller I²C lines communicating with 5 V sensors on Port P. The translation is automatic and requires no external components.
Does PCAL6408AEXX support interrupt debouncing or edge detection?
Yes - the PCAL6408AEXX supports hardware input latching via register 42h, which captures and holds the logic state that triggered an interrupt until the Input Port register (00h) is read. Combined with the read-only Interrupt Status register (46h), this enables precise edge detection and eliminates software debouncing for fast-moving inputs like push buttons or motion sensors.
What is the default power-on behavior of PCAL6408AEXX interrupt functionality?
At power-on, all eight bits of the Interrupt Mask register (45h) default to logic 1, disabling interrupts on all P0–P7 inputs. This prevents spurious INT assertions during system startup. To enable interrupts, the host must write 0 to the desired mask bits. The PCAL6408AEXX also powers up with all I/Os configured as inputs (Configuration register 03h = 0xFF) and the INT pin de-asserted.
Can PCAL6408AEXX directly drive LEDs, and what is its output current capability?
Yes - each Port P pin (P0–P7) of the PCAL6408AEXX supports 25 mA sink current in output mode, enabling direct LED driving without external transistors. Outputs can be configured as push-pull or open-drain via register 4Fh, and drive strength is adjustable per pin (0.25× to 1×) using registers 40h/41h to optimize rise/fall times and EMI performance.
PCAL6408AEXX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- Agile
- Package/Case:
- 16-XFBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Number of I/O:
- 8
- Interface:
- I2C, SMBus
- Interrupt Output:
- Yes
- Features:
- POR
- Output Type:
- Open Drain, Push-Pull
- Current - Output Source/Sink:
- 10mA, 25mA
- Clock Frequency:
- 400 kHz
- Voltage - Supply:
- 1.65V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-XFBGA (1.6x1.6)
PCAL6408AEXX FAQ
1.How can I place an order for PCAL6408AEXX through Aetrix?
Please submit a Request for Quotation (RFQ) for PCAL6408AEXX 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 PCAL6408AEXX reliable?
The price and inventory of PCAL6408AEXX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCAL6408AEXX is usually 5 days.
3.What payment methods are accepted for PCAL6408AEXX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCAL6408AEXX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCAL6408AEXX?
PCAL6408AEXX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCAL6408AEXX 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 PCAL6408AEXX?
For technical support, including PCAL6408AEXX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCAL6408AEXX requirements.
6.How does Aetrix verify that PCAL6408AEXX is sourced from the original manufacturer or authorized distributors?
All PCAL6408AEXX 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 PCAL6408AEXX meets industry standards.
7.What is the process for return or replacement of PCAL6408AEXX?
All PCAL6408AEXX units undergo pre-shipment inspection (PSI). If there is an issue with PCAL6408AEXX, 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 PCAL6408AEXX part is unused and in its original packaging.
Return procedure for PCAL6408AEXX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
PCAL6408AEXX Tags
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