NXP Semiconductors P87C51RD2BA,512

Overview

P87C51RD2BA,512 from NXP Semiconductors (formerly Philips) is an 8-bit OTP microcontroller based on the 80C51 architecture, featuring 64 KB on-chip OTP program memory, 1 KB RAM, four 8-bit I/O ports, three 16-bit timers (T0/T1/T2), a full-duplex enhanced UART with framing error detection, and a Programmable Counter Array (PCA) supporting PWM and capture/compare functions. It operates at 2.7–5.5 V and delivers up to 33 MHz performance in 12-clock mode for motor control and industrial embedded applications.

For engineers reviewing the P87C51RD2BA,512 datasheet, P87C51RD2BA,512 pinout, P87C51RD2BA,512 application, or P87C51RD2BA,512 equivalent, key selection criteria include its 64 KB OTP capacity, 1 KB RAM, PLCC-44 package with verified pin mapping, 6-/12-clock mode flexibility, PCA-based PWM capability, and support for low-power idle and power-down modes in industrial temperature range (0 to +70 °C).

Technical Context

The P87C51RD2BA,512 implements an accelerated 80C51 CPU core with dual clock modes (6- or 12-clock per machine cycle), selectable via OTP bit OX2 or SFR bit X2 in CKCON. Its enhanced peripheral set includes Timer 2 with capture/compare and baud-rate generation, a full-duplex UART with automatic address recognition, and a 5-channel PCA supporting simultaneous PWM outputs and event capture.

It integrates hardware features for deterministic real-time control: asynchronous port reset, programmable clock-out on P1.0 (61 Hz–8 MHz), security bits (3), 64-byte encryption array, and four-level nested interrupt structure with seven sources - enabling robust motor drive, sensor interface, and industrial timing applications without external logic.

Key Specifications

Pinout & Package

Package: Plastic Leaded Chip Carrier (PLCC), 44-pin, SOT187-2 footprint, body size 16.6 × 16.6 mm, lead pitch 0.5 mm, operating temperature range 0 to +70 °C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT89C51ED2-UM and P89V51RD2FA, the P87C51RD2BA,512 offers hardened OTP code security and legacy qualification for cost-sensitive industrial deployments, while trading reprogrammability for immunity to accidental or malicious firmware overwrite - making it optimal for fixed-function, high-volume embedded controllers.

Availability

P87C51RD2BA,512 is available at Aetrix Electronics and suitable for motor control systems, industrial PLC I/O modules, and smart energy meters requiring stable component supply, long-lifecycle assurance, and OTP-based firmware security.

Supply support for P87C51RD2BA,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

NXP Semiconductors is a global semiconductor leader delivering high-performance analog, logic, and microcontroller solutions for automotive, industrial, and IoT markets.

The P87C51RD2BA,512 belongs to NXP's legacy 80C51 OTP microcontroller family, designed specifically for cost-effective, high-reliability industrial control applications where firmware immutability, low-power operation, and pin-compatible upgrade paths are essential.

FAQ

What is the maximum operating frequency of the P87C51RD2BA,512 and under what conditions?

The P87C51RD2BA,512 achieves a maximum operating frequency of 33 MHz at VCC = 5 V in 12-clock mode, and 30 MHz at VCC = 3 V. In 6-clock mode, the same oscillator frequency yields doubled instruction throughput - e.g., a 16 MHz crystal delivers ~2.75 MIPS in 12-clock mode and ~5.5 MIPS in 6-clock mode. The device must be operated within its specified 2.7–5.5 V supply range and ambient temperature (0 to +70 °C) to guarantee this performance.

Does the P87C51RD2BA,512 support in-system programming (ISP)?

No, the P87C51RD2BA,512 does not support in-system programming. It uses one-time-programmable (OTP) memory, which is programmed externally using parallel programming hardware before soldering. Unlike Flash-based derivatives such as the AT89C51ED2, the P87C51RD2BA,512 cannot be reprogrammed after assembly - making it suitable for production firmware with strict version control and anti-tampering requirements.

How many PWM channels does the P87C51RD2BA,512 provide, and how are they implemented?

The P87C51RD2BA,512 provides five independent PWM outputs via its Programmable Counter Array (PCA), accessible through pins CEX0–CEX4 on Port 1. Each channel supports adjustable duty cycle and frequency using 16-bit reload registers (CCAPnH/CCAPnL). PWM operation is configured per channel using CCAPMn SFR bits - enabling simultaneous motor phase control, LED dimming, and fan speed regulation without consuming CPU cycles.

What package type and pin count does the P87C51RD2BA,512 use?

The P87C51RD2BA,512 uses a 44-pin Plastic Leaded Chip Carrier (PLCC) package, designated SOT187-2. It features a square body with J-leads, 0.5 mm lead pitch, and is rated for 0 to +70 °C operation. This package is compatible with standard PLCC sockets and reflow soldering processes, and shares pin compatibility with other members of the P87C51RA2/RB2/RC2/RD2 family in the same PLCC variant.

Can the P87C51RD2BA,512 operate from a 3.3 V supply, and what performance trade-offs apply?

Yes, the P87C51RD2BA,512 supports 3.3 V operation within its 2.7–5.5 V range. At 3.3 V, the maximum guaranteed frequency is 16 MHz in both 6- and 12-clock modes - lower than the 30/33 MHz achievable at 5 V. All I/O pins remain CMOS/TTL compatible, and internal peripherals (UART, PCA, timers) function correctly. Designers should verify timing margins for external memory interfaces and ensure oscillator stability at reduced VCC.