NXP Semiconductors PCA8581T/6,112

Overview

PCA8581T/6,112 from NXP Semiconductors (formerly Philips) is a 128 × 8-bit I²C-bus EEPROM in SO8 package, operating at 4.5–5.5 V, with integrated voltage multiplier and timer for autonomous write operations, 8-byte page write mode, and hardware address pins A0–A2 enabling up to eight devices on one bus. It serves as non-volatile configuration storage in embedded control systems requiring low-power, reliable data retention.

For engineers reviewing the PCA8581T/6,112 datasheet, PCA8581T/6,112 pinout, PCA8581T/6,112 application, or PCA8581T/6,112 equivalent, this page delivers verified electrical parameters, I²C timing compliance (100 kHz), pin-level circuit roles, real-world use cases in industrial controllers and sensor nodes, and validated alternative parts with documented functional and voltage-range differences.

Technical Context

The PCA8581T/6,112 implements a standard I²C slave interface with fixed 7-bit slave address prefix '1010' and three programmable address bits (A2–A0), supporting multi-device bus topology. Its internal architecture includes an auto-incrementing word address register, on-chip voltage multiplier eliminating external charge pumps, and automatic erase-before-write logic ensuring byte-level integrity without host intervention.

Write operations execute in 7–10 ms per page (up to 8 bytes), during which the device ignores I²C traffic; read operations support unlimited sequential byte access with automatic address wrap. The SDA line functions bidirectionally with open-drain output, while TEST pin is a dedicated test output-unconnected in normal operation and electrically isolated from VDD/VSS per diode protection design.

Key Specifications

Pinout & Package

PCA8581T/6,112 is housed in an SO8 plastic small outline package (SOT96-1), 3.9 mm body width, 1.27 mm lead pitch, surface-mount compatible with reflow and wave soldering per JEDEC MS-012AA.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C EEPROM applications.

Compared with PCA8581T/6,112, AT24C01C-SSHM-T offers broader supply compatibility and vastly higher endurance but requires external timing control for writes, while M95010-WMN6TP trades I²C simplicity for faster SPI throughput and eliminates bus arbitration complexity at the cost of additional signal routing.

Availability

PCA8581T/6,112 is available at Aetrix Electronics and suitable for industrial control systems, smart sensor nodes, consumer electronics configuration storage, and embedded bootloader parameter retention requiring stable component supply across long production lifecycles.

Supply support for PCA8581T/6,112 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, formerly Philips Semiconductors, is a global leader in high-performance analog and mixed-signal ICs, with deep expertise in interface, memory, and automotive-grade components.

The PCA8581T/6,112 belongs to NXP's legacy I²C EEPROM family, designed specifically for robust, low-power non-volatile storage in resource-constrained embedded systems where bus simplicity and write autonomy are critical.

FAQ

What is the maximum I²C clock frequency supported by the PCA8581T/6,112?

The PCA8581T/6,112 supports standard-mode I²C operation up to 100 kHz, with guaranteed timing margins including tLOW ≥ 4.7 µs and tHIGH ≥ 4.0 µs. It does not support fast-mode (400 kHz) or higher speeds. This limit is defined by internal oscillator tolerance and write-cycle timing constraints, and exceeding it may result in communication failures or incomplete writes.

Does the PCA8581T/6,112 require external components for write operations?

No, the PCA8581T/6,112 integrates a voltage multiplier and internal timer, eliminating the need for external charge pumps, capacitors, or timing resistors. All write operations-including erase and programming-are fully autonomous once initiated via I²C. Only standard I²C pull-up resistors on SDA and SCL are required for bus operation.

How many PCA8581T/6,112 devices can share the same I²C bus?

Up to eight PCA8581T/6,112 devices can operate on a single I²C bus using the three hardware address pins A0, A1, and A2. Each combination of HIGH/LOW states on these pins sets a unique 3-bit extension to the fixed '1010' base address, yielding eight distinct 7-bit slave addresses (0xA0–0xA7). No additional address decoding logic is required.

What is the function of the TEST pin on the PCA8581T/6,112?

TEST is a dedicated test output pin used during wafer-level and final test; it is electrically isolated from VDD and VSS by internal diodes and must be connected to VSS, VDD, or left open-circuit in application circuits. It carries no functional role during normal operation and should never be driven by external logic or used as a general-purpose I/O.

Is the PCA8581T/6,112 compatible with modern 3.3 V I²C systems?

No-the PCA8581T/6,112 is specified only for 4.5–5.5 V operation (PCA8581 variant). It is not rated for 3.3 V supply or I/O levels. Attempting to operate it at 3.3 V may cause unreliable communication, incomplete writes, or premature wear. For 3.3 V systems, consider the PCA8581C variant (2.5–6.0 V) or modern alternatives like AT24C01C.