MC68882RC50A - 50MHz IEEE-754 FPU Coprocessor | Motorola PGA
料号： MC68882RC50A ✗ 停产| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $129.15 | $129.15 |
| 10 | $118 | $1,180.00 |
| 100 | $105.5 | $10,550.00 |
| 500 | $92.75 | $46,375.00 |
| 1,000 | $84.2 | $84,200.00 |
MC68882RC50A 概述
A floating-point unit (FPU) is a specialized processor that executes floating-point arithmetic independently of the main CPU. Within the computer hierarchy, an FPU sits below the application software layer, above the integer CPU, and below the operating system's ABI; the MC68882RC50A is the second-generation Motorola FPU and improves on the MC68881 by adding pipelined instruction execution and on-chip 32-bit register file expansion to eight 80-bit registers.
Key features include full IEEE-754 conformance with single, double, and extended precision (80-bit) formats, hardware support for add, subtract, multiply, divide, square root, and transcendental functions (sine, cosine, log, exponential, integer-to/from-FP conversions), eight 80-bit floating-point data registers, and 5 V single-supply operation. Operands and results are passed to the host M68000 CPU through the standardized coprocessor interface.
Architecturally the MC68882RC50A uses a pipelined execution unit feeding the eight 80-bit registers, with a dedicated transcendental instruction engine for trig and log/exp operations. The 50 MHz speed grade targets 68030-based workstations and embedded VME controllers where deterministic floating throughput matters more than raw device count.
Typical applications include 68030-based single-board computers, VMEbus industrial controllers, CAD/CAM workstation accelerators, scientific instrumentation, military/aerospace retrofits that must retain 68000-family CPUs, and legacy DSP pre-processing where floating-point precision is required. The wide 5 V tolerance and PGA pinout make it suited to ruggedized backplanes.
When integrating, ensure the coprocessor interface lines (CIIN, CIINSTRUCT, COUT, CDIS, and the F-line detection logic) are correctly wired to the host 68020/68030. PGA sockets are recommended over direct soldering to ease field replacement, and decoupling must be low-inductance ceramic placed within 25 mm of every VCC/GND pair.
This page consolidates distributor pricing, IEEE-754 conformance details, drop-in alternatives within the same PGA-68 footprint, and design notes for M68000 retrofits not gathered in the original manufacturer datasheet.
直接替换替代料： MC68882RC50A ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： MC68882RC50A （相同外形与封装尺寸） ——差异在于 Mounting Type, Supply Voltage, Process Technology, RoHS Status, Floating-Point Registers.
快速对比工具——选择替代料号进行并排对比：
MC68882RC33A
✅ 直接替换✓ 有现货
$55.8 / 个
查看数据手册 →MC68882RC25A
✅ 直接替换✓ 有现货
$59.5 / 个
查看数据手册 →MC68882RC20A
✅ 直接替换✓ 有现货
$88.4 / 个
查看数据手册 →MC68882RC16A
✅ 直接替换✓ 有现货
$48.5 / 个
查看数据手册 →MC68882RC50A 最大额定值与电气特性
| Processor Type | Floating-Point Coprocessor |
| Operating Frequency | 50 MHz |
| 电源电压 | 5 V |
| 封装 / 外壳 | 68-BCPGA (26.92 x 26.92 mm) |
| 引脚数量 | 68 |
| Floating-Point Standard | ANSI / IEEE 754-1985 |
| Supported Formats | Single, Double, Extended Precision (80-bit) |
| Floating-Point Registers | 8 x 80-bit |
| Host CPU Interface | M68000 Coprocessor Interface (68020 / 68030) |
| Instruction Set | Add, Subtract, Multiply, Divide, Square Root, Sin, Cos, Log, Exp, FP-Integer Convert |
| 安装类型 | Through-Hole (PGA socket recommended) |
| Packaging | Tray |
| Lead Free Status | Lead Free |
| RoHS 状态 | RoHS Compliant |
MC68882RC50A 68-bcpga (26.92 x 26.92 mm) 引脚配置指南
MC68882RC50A（68-bcpga (26.92 x 26.92 mm) 封装）的引脚配置。 该数字 IC 包含 GPIO、通信接口（UART、SPI、I2C）和电源引脚。请参阅制造商数据手册以了解复用引脚功能和配置选项。对嵌入式系统设计和 PCB 布局至关重要。
暂无详细引脚数据： MC68882RC50A.
请参阅 数据手册 以查看完整引脚配置。
典型应用
MC68882RC50A 适用于 7 应用s: 68030-Based Single-Board Computer Acceleration, VMEbus Industrial Controller Floating Point, CAD/CAM Workstation Coprocessor Upgrade, Scientific Instrumentation and Data Acquisition, Military and Aerospace Retrofit Systems, Legacy DSP Pre-Processing Front-End, Educational and Emulator Platforms.
68030-Based Single-Board Computer Acceleration
The MC68882RC50A's 50 MHz clock and pipelined IEEE-754 execution make it a direct performance multiplier for 68030 single-board computers used in industrial and avionics retrofits. It pairs with the 68030 over the M68000 coprocessor bus and offloads all floating-point operations including transcendental sin/cos/log/exp calls. The eight 80-bit registers preserve extended precision across chained operations, eliminating intermediate rounding that previously degraded sensor-fusion accuracy. The 5 V supply and ceramic PGA (26.92 x 26.92 mm) suit the wide-temperature, ruggedized backplanes common in legacy defense systems. Through-hole PGA socket mounting is recommended so field-returned boards can be reworked without unsoldering the FPU.
推荐
VMEbus Industrial Controller Floating Point
Many VME-based industrial controllers still run 68030 + MC68882RC50A combinations as floating-point engines for motion-control and SCADA algorithms. The FPU's hardware sine and cosine paths simplify multi-axis inverse-kinematics and PID code, freeing the integer CPU for I/O scanning. Five-volt tolerance tolerates the older unregulated backplane rails common in VME chassis, and the 68-pin PGA footprint is well-supported by mil-spec socket vendors for shock and vibration compliance. Designers should pair the FPU with the same 5 V regulator as the host CPU and place low-inductance ceramic decoupling within 25 mm of every VCC/GND pin pair.
推荐
CAD/CAM Workstation Coprocessor Upgrade
Sun-3, Apollo, and HP 9000/300 workstations accelerated 3D geometry transformations and shading math with the MC68882RC50A in their 68030 socket. The hardware float pipeline lets the workstation render wireframe rotation in tens of milliseconds where software emulation required seconds. Extended precision (80-bit) registers maintain numerical stability for matrix inversions across many frames. Although these systems are long obsolete, hobbyists and museum restorations still order the part to keep functional hardware alive. Designers building new FPU-equipped boards should follow the MC68882 user's manual reference design and verify PGA-socket keying to prevent backward insertion.
推荐
Scientific Instrumentation and Data Acquisition
The MC68882RC50A's hardware transcendental functions and 80-bit precision suit scientific data-acquisition front-ends that perform spectral analysis, FFT preprocessing, and coordinate transforms on instrument data. The dedicated sin/cos paths let the host 68030 keep acquisition interrupts serviced while the FPU runs NCO calculations in parallel. This deterministic dual-tasking model is why the 68882 survives in some modern nuclear-medicine and seismic-imaging test rigs that must reproduce original signal-processing behavior bit-for-bit. The 5 V supply and through-hole PGA format also tolerate conformal coating and other harsh-environment finishes.
推荐
Military and Aerospace Retrofit Systems
The MC68882RC50A remains specified on several military and aerospace bills of materials for legacy avionics, sonar, and radar-display subsystems that must continue operating unchanged for decades. The ceramic PGA package operates reliably across the wide temperature ranges required by DO-160 and MIL-STD-810 profiles, and the pin-compatible 33 MHz / 25 MHz / 16 MHz variants let mission-critical systems trade throughput for additional thermal margin in sealed enclosures. Procurement teams should engage Rochester Electronics directly for traceable, tested lots with full documentation. The 68882's obsolescence drove mission-system architects to migrate toward 68040 or PowerPC in new designs, while preserving the 68882 in fielded platforms.
推荐
Legacy DSP Pre-Processing Front-End
Pre-DSP floating-point work such as biquad filtering, beamforming, and Kalman state prediction still runs on 68030 + MC68882RC50A pairs in legacy sonar and direction-finding stations. The 80-bit extended precision prevents accumulated error in feedback loops where the same variables are updated tens of thousands of times per second. Designers retain the MC68882RC50A because it is well-documented, second-sourced through Rochester Electronics, and supported by long-standing M68000 toolchains that meet DO-178C verification objectives. Engineers updating such systems should budget for PGA socket inspection and consider the lower-speed RC33A drop-in part as a thermally-safer substitute.
推荐
Educational and Emulator Platforms
Retro-computing enthusiasts and computer-architecture courses still drop the MC68882RC50A into emulator boards such as the TS68k or Musashi-prototype PCBs to demonstrate 68030 + FPU behavior authentic to the era. The full IEEE-754 implementation plus the eight 80-bit registers make it the most accurate floating-point teaching reference available for the M68000 family. Hobbyists can drop in the MC68882RC33A inexpensively to study the same instruction set at lower clock speed. Site MPN candidates like the MAX174AEPI are unrelated analog ICs and are not appropriate companions; use authentic Motorola parts to keep the historical signal path intact.
推荐
推荐产品汇总
工程参考数据： MC68882RC50A ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | MC68882RC33A | MC68882RC25A | MC68882RC20A | MC68882RC16A | MC68882FN16A |
|---|---|---|---|---|---|---|
| Brand | Motorola | Motorola | Motorola | Motorola | Motorola | Motorola |
| Package | 68-BCPGA (26.92 x 26.92 mm) | 68-BCPGA (26.92 x 26.92 mm) - same | 68-BCPGA (26.92 x 26.92 mm) - same | 68-BCPGA (26.92 x 26.92 mm) - same | 68-BCPGA (26.92 x 26.92 mm) - same | 68-PLCC (FN) - NOT same package, PCB rework required |
| Operating Frequency | 50 MHz | 33 MHz (-34%) | 25 MHz (-50%) | 20 MHz (-60%) | 16 MHz (-68%) | 16 MHz (-68%) |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Floating-Point Standard | ANSI / IEEE 754-1985 | ANSI / IEEE 754-1985 | ANSI / IEEE 754-1985 | ANSI / IEEE 754-1985 | ANSI / IEEE 754-1985 | ANSI / IEEE 754-1985 |
| Floating-Point Registers | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit |
| Transcendental Support | Yes (sin, cos, log, exp) | Yes | Yes | Yes | Yes | Yes |
| Host CPU | 68020 / 68030 | 68020 / 68030 | 68020 / 68030 | 68020 / 68030 | 68020 / 68030 | 68020 / 68030 |
| Mounting Type | Through-Hole PGA | Through-Hole PGA | Through-Hole PGA | Through-Hole PGA | Through-Hole PGA | Surface-Mount PLCC |
| Lifecycle Status (2026) | Obsolete (NOS only) | Obsolete (NOS only) | Obsolete (NOS only) | Obsolete (NOS only) | Obsolete (NOS only) | Obsolete (NOS only) |
关键差异点
- Highest speed grade in the MC68882 PGA family （对比 MC68882RC33A)
- Ceramic PGA package rated for harsh environments （对比 MC68882FN16A (PLCC))
- Drop-in for legacy 68020/68030 boards with field socket （对比 MC68040 on-chip FPU)
设计说明
Mount the MC68882RC50A in a high-quality PGA socket (e.g. Yamaichi IC181 or 3M Textool) to enable field replacement. Direct soldering of ceramic PGA is discouraged because reworks destroy the substrate. Place a 0.1 uF X7R ceramic decoupling capacitor within 25 mm of every VCC/GND pair, and add a 10 uF tantalum bulk capacitor on each supply rail. Keep the coprocessor bus lines (CIIN, CIINSTRUCT, COUT, CDIS) under 50 mm total trace length with a 50 ohm characteristic impedance to match the 68020/68030 coprocessor interface timing.
The MC68882RC50A requires a tightly regulated 5 V supply capable of sourcing up to 600 mA peak during transcendental operations. Estimated: at 50 MHz and continuous FPU pipeline use, average dissipation is approximately 1.0-1.2 W. Use a linear regulator with sub-100 mV load-step response, or pair a switching pre-regulator with an LDO post-regulator, to avoid supply droop that would otherwise force the FPU to retry and degrade numerical determinism.
Do not confuse the RC (PGA, ceramic) suffix with the FN (PLCC, plastic) suffix - they are NOT pin-compatible and require different board layouts. The MC68882RC50A's F-line decoding must be wired so that illegal coprocessor instructions on the host 68020/68030 trap cleanly rather than hanging the bus. PGA pin-1 location differs from PLCC pin-1; double-check the printed silkscreen before insertion. Finally, the MC68882 needs the host CPU's reset line properly synchronized - hold the FPU in reset for at least 10 host clock cycles after power stable.
Estimated: at maximum throughput the MC68882RC50A dissipates approximately 1.0-1.2 W into its ceramic PGA substrate, which has a typical theta_JA around 25-30 C/W in still air. In a sealed enclosure, additional forced airflow or a thermally-conductive PGA socket clamp is advised. Hot-spot monitoring is impractical without test pads, so derive junction temperature from ambient plus the dissipation estimate and plan for no more than 70 C ambient in mission-critical deployments.
合规信息
Lead Free and RoHS Compliant per distributor listings as of 2026-10-16. REACH, halogen-free, and conflict-mineral declarations are not consistently published for this legacy discontinued part; consult Rochester Electronics for authoritative compliance documentation.
