NXP Semiconductors P80C51FA-4A,512

Overview

P80C51FA-4A,512 from Philips Semiconductors is an 8-bit OTP microcontroller based on the 80C51 architecture, featuring 8 KB ROM, 256 bytes RAM, programmable PCA (Programmable Counter Array), and full-duplex enhanced UART. It operates from 2.7 V to 5.5 V at up to 16 MHz and targets embedded control applications requiring pulse-width modulation, high-speed I/O, and multi-source interrupt handling.

For engineers reviewing the P80C51FA-4A,512 datasheet, P80C51FA-4A,512 pinout, P80C51FA-4A,512 application, or P80C51FA-4A,512 equivalent, key selection criteria include its 44-pin PLCC package, PCA-based capture/compare capability, 4-level priority nested interrupt structure, and compatibility with standard 80C51 instruction set and toolchains.

Technical Context

The P80C51FA-4A,512 implements a static CMOS 80C51 core with architectural enhancements including a 5-channel PCA for PWM, input capture, and software timers - distinct from basic 8XC54/58 variants lacking PCA. Its enhanced UART supports framing error detection and automatic address recognition for multiprocessor communication.

It supports three low-power modes: Stop Clock (oscillator halted, RAM/SFRs retained), Idle (CPU halted, peripherals active), and Power-Down (oscillator stopped, minimal current draw). Reset is triggered by a high level on RST for ≥2 machine cycles while XTAL1/XTAL2 are running.

Key Specifications

Pinout & Package

Package: 44-pin Plastic Leaded Chip Carrier (PLCC), SOT187-2 footprint, suitable for socketed or surface-mount PCB layouts with thermal and mechanical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with P87C51FA-4A, the P80C51FA-4A,512 offers wider supply voltage flexibility (2.7–5.5 V vs. 5 V only), while versus P80C51RA+-4A it trades 256-byte RAM and no hardware WDT for lower unit cost and reduced power in simpler control tasks.

Availability

P80C51FA-4A,512 is available at Aetrix Electronics and suitable for motor control systems, industrial sensor nodes, legacy equipment retrofits, and power supply monitors requiring stable component supply across extended product lifecycles.

Supply support for P80C51FA-4A,512 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

Philips Semiconductors (now NXP Semiconductors) is a global semiconductor innovator with leadership in automotive, industrial, and connectivity solutions.

The 80C51FA family was designed for cost-effective, low-power embedded control in industrial automation, instrumentation, and retrofit applications where 8051 compatibility, OTP security, and integrated peripherals reduce BOM count.

FAQ

What is the maximum operating frequency of the P80C51FA-4A,512?

The P80C51FA-4A,512 is rated for up to 16 MHz operation across its full 2.7 V–5.5 V supply range. At 5 V, it achieves approximately 2 MIPS. The device supports full static operation, meaning it can run at any frequency from 0 Hz (clock stopped) up to 16 MHz without loss of internal state - a key feature for dynamic power scaling in the P80C51FA-4A,512.

Does the P80C51FA-4A,512 include a hardware watchdog timer?

No, the P80C51FA-4A,512 does not integrate a hardware watchdog timer. That feature is present in the later P80C51RA+ family (e.g., P80C51RA+-4A) but omitted in the FA-series to reduce die size and cost. Designers requiring fail-safe reset must implement external watchdog circuitry or use software-timed resets via the PCA or Timer 2 - both available in the P80C51FA-4A,512.

What package type is used for the P80C51FA-4A,512?

The P80C51FA-4A,512 uses a 44-pin Plastic Leaded Chip Carrier (PLCC) with SOT187-2 mechanical outline. This surface-mount package features J-leads for reliable solder joints and thermal performance suitable for industrial environments. It is not pin-compatible with DIP-40 or QFP-44 variants of the same family - the P80C51FA-4A,512 requires dedicated PLCC footprint and reflow profile.

How much internal RAM does the P80C51FA-4A,512 provide?

The P80C51FA-4A,512 provides 256 bytes of internal RAM, mapped identically to the standard 80C51 architecture (addresses 00H–FFH). This includes 128 bytes of general-purpose RAM plus 128 bytes of bit-addressable SFR space. Unlike the P80C51RA+ variant (512 bytes), the P80C51FA-4A,512's RAM is fixed at 256 bytes and cannot be expanded on-chip - external RAM may be added via Port 0/2 and RD/WR signals.

Can the P80C51FA-4A,512 execute code from external memory?

Yes, the P80C51FA-4A,512 supports external program memory execution when the EA/VPP pin is held low. In this mode, it fetches instructions from external ROM/EPROM starting at address 0000H. When EA is high, it executes exclusively from its internal 8 KB OTP. The P80C51FA-4A,512 uses Port 0 (AD0–AD7) and Port 2 (A8–A15) for external bus interfacing, with PSEN controlling external program memory reads - fully compatible with standard 80C51 external memory expansion.