NXP Semiconductors P87C51SFPN,112

Overview

P87C51SFPN,112 from Philips Semiconductors is an 8-bit OTP-based microcontroller in the 80C51 architecture family, featuring 4 K × 8 on-chip OTP memory, 128 × 8 RAM, four 8-bit I/O ports, three 16-bit counter/timers, and a full-duplex UART. It operates across –40 °C to +85 °C at 2.7–5.5 V supply, supports idle and power-down modes, and is packaged in a 40-pin plastic DIP (SOT129-1). It serves as a core control unit in industrial sensor interfaces and legacy embedded instrumentation.

For engineers reviewing the P87C51SFPN,112 datasheet, P87C51SFPN,112 pinout, P87C51SFPN,112 application, or P87C51SFPN,112 equivalent, this page delivers verified functional identity, validated pin roles, confirmed low-voltage operation (2.7–5.5 V), real-time power management (idle/power-down), and precise OTP/ROM memory mapping - all essential for legacy system maintenance and drop-in replacement planning.

Technical Context

The P87C51SFPN,112 implements a static CMOS 8051 CPU core with full backward compatibility to MCS-51 instruction set, supporting zero-frequency stop-clock operation and Boolean bit manipulation. Its memory subsystem includes 4 KB of one-time-programmable (OTP) ROM and 128 bytes of on-chip RAM, with external program/data memory access via multiplexed Port 0 (AD0–AD7) and Port 2 (A8–A15).

It integrates a six-source, four-priority nested interrupt controller, programmable clock-out on P1.0 (61 Hz–4 MHz at 16 MHz oscillator), and Timer 2 configured for capture, auto-reload, or baud-rate generation - all operating under 2.7–5.5 V supply without requiring external voltage translation.

Key Specifications

Pinout & Package

Package: 40-pin Plastic Dual In-line Package (DIP), SOT129-1, through-hole mountable with 0.6-inch width and standard 0.1-inch pin pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT89C51-24PI and STC89C52RC-PD, the P87C51SFPN,112 offers guaranteed OTP firmware immutability and industrial temperature support out-of-box, whereas alternatives trade permanence for reprogrammability or memory expansion - making P87C51SFPN,112 optimal for fixed-function, long-lifecycle deployments where firmware integrity is critical.

Availability

P87C51SFPN,112 is available at Aetrix Electronics and suitable for industrial sensor interfaces, legacy PLC I/O modules, and embedded instrumentation front-ends requiring stable component supply, long-term obsolescence management, and guaranteed industrial temperature performance.

Supply support for P87C51SFPN,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

Philips Semiconductors (now NXP Semiconductors) is a pioneer in mixed-signal IC design, delivering high-reliability components for automotive, industrial, and consumer applications since the 1950s.

The P87C51SFPN,112 belongs to the 80C51/87C51 family - designed specifically for cost-sensitive, low-power embedded control in harsh environments where firmware permanence, wide voltage operation, and proven 8051 compatibility are mandatory.

FAQ

What is the memory configuration of the P87C51SFPN,112?

The P87C51SFPN,112 contains 4 K × 8 one-time-programmable (OTP) ROM for program storage and 128 × 8 bytes of on-chip RAM for data and stack operations. This configuration eliminates the need for external program memory in most standalone applications and supports full 64 KB external addressing when required. The OTP ensures firmware integrity and prevents unauthorized modification after programming.

Does the P87C51SFPN,112 support low-voltage operation?

Yes, the P87C51SFPN,112 operates across a supply voltage range of 2.7 V to 5.5 V, enabling direct integration with both 3.3 V and 5 V system rails without level-shifting circuitry. This dual-voltage capability simplifies power architecture in mixed-signal designs and supports battery-powered operation down to 2.7 V while maintaining full functionality including UART, timers, and I/O drive strength.

How does the power-down mode work on the P87C51SFPN,112?

In power-down mode, the P87C51SFPN,112 stops the oscillator and disables all digital circuitry except RAM and SFRs, reducing current consumption to microamp levels. Wake-up is triggered by either a hardware reset or an enabled external interrupt (INT0 or INT1, configured as level-sensitive). The P87C51SFPN,112 retains RAM contents down to 2.0 V, ensuring state persistence across brownout conditions.

Can the P87C51SFPN,112 generate a precise clock signal for external circuitry?

Yes, the P87C51SFPN,112 supports programmable clock-out on P1.0, delivering a 50% duty-cycle square wave ranging from 61 Hz to 4 MHz (at 16 MHz oscillator). This is achieved by configuring Timer 2 in auto-reload mode with appropriate RCAP2H/RCAP2L values. The feature eliminates the need for external clock generators in synchronous peripheral interfacing such as ADC sampling or logic state machines.

What is the role of the EA/VPP pin on the P87C51SFPN,112?

The EA/VPP pin on the P87C51SFPN,112 serves two functions: External Access Enable (EA) and Programming Supply Voltage (VPP). When EA is high, the P87C51SFPN,112 executes from internal OTP memory; when low, it fetches code from external program memory starting at 0000H. During OTP programming, VPP = 12.75 V is applied to this pin to enable write operations - a requirement strictly enforced by the internal programming logic of the P87C51SFPN,112.