MC68HC908RF2CFA - 8-Bit HC08 4MHz MCU 2KB Flash | NXP
料号： MC68HC908RF2CFA ✗ 停产| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.1 | $5,100.00 |
MC68HC908RF2CFA 概述
What is an 8-bit microcontroller? An 8-bit MCU is a small computer-on-a-chip that executes instructions on 8-bit data words and integrates CPU, RAM, non-volatile program memory, and peripherals in one package. It belongs to the broader taxonomy of microcontrollers -> microcomputers -> embedded processors -> semiconductors. The MC68HC908RF2CFA belongs specifically to the HC08 sub-family, which uses a CISC architecture and is intended for cost-sensitive embedded control applications where deterministic GPIO behavior and small memory footprints are sufficient.
Key features include on-chip FLASH program memory supporting in-system reprogramming, an internal oscillator that eliminates the need for an external crystal in many designs, low-power HCMOS process technology, and an industrial operating temperature grade. The integrated peripherals typically include a timer module, basic serial communication, and keyboard interrupt logic suitable for human-interface and small-control applications.
The HC08 CPU core uses a von-Neumann architecture with a 16-bit stack pointer and 8-bit accumulator plus index register pair. The 2 KB FLASH is organized as 2K x 8 and supports in-application programming via the standard Freescale/NXP monitor routines. The internal oscillator design reduces BOM cost and PCB area, while the 32-pin LQFP provides easy hand-soldering for prototypes and full compatibility with automated surface-mount assembly.
Typical applications include remote keyless entry (RKE) transmitters, simple security key fobs, low-end RF transmitter controllers, consumer electronics human-interface devices, and battery-powered industrial sensors. The combination of low voltage operation, internal oscillator, and small FLASH makes it especially attractive for cost-optimized, space-constrained designs.
When designing with this part, confirm availability through NXP authorized distributors because the M68HC908 line has been superseded by newer families (S08, S12, Kinetis) and stock may be limited. For new designs, evaluate the current-generation equivalents to avoid obsolescence risk. Ensure unused I/O pins are configured properly to minimize power consumption.
直接替换替代料： MC68HC908RF2CFA ——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： MC68HC908RF2CFA （相同外形与封装尺寸） ——差异在于 Operating Temperature, Program Memory Size, RAM Size.
快速对比工具——选择替代料号进行并排对比：
MC68HC908RF2MFA
✅ 直接替换📋 参考替代料（不在目录中）
MC68HC908RF2CFB
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
MC68HC908JL8CFAE
✅ 直接替换✓ 有现货
$6.4 / 个
查看数据手册 →MC68HC908RF2CFA 最大额定值与电气特性
| Product Type | 8-bit Microcontroller (MCU) |
| CPU Family | M68HC08 |
| Core | HC08 (CISC, 8-bit) |
| Program Memory Size | 2 KB (2K x 8) |
| Program Memory Type | FLASH |
| RAM Size | 128 x 8 (128 bytes) |
| Number of I/O | 12 |
| Bus Frequency / Speed | 4 MHz |
| Oscillator Type | Internal |
| 电源电压 | 2.5 V / 3.3 V |
| 封装 / 外壳 | 32-LQFP (7x7 mm) |
| 安装类型 | Surface Mount |
| Packaging | Tray |
| 工作温度 | Industrial grade |
| Architecture | von-Neumann |
| Process Technology | HCMOS |
| Terminal Form | GULL WING |
MC68HC908RF2CFA 引脚配置
| 引脚 1 | PTB0/KBD0 — Port B bit 0 / keyboard interrupt 0 |
| 引脚 2 | PTB1/KBD1 — Port B bit 1 / keyboard interrupt 1 |
| 引脚 3 | PTB2/KBD2 — Port B bit 2 / keyboard interrupt 2 |
| 引脚 4 | PTB3/KBD3 — Port B bit 3 / keyboard interrupt 3 |
| 引脚 5 | PTA0 — Port A bit 0 (general-purpose I/O) |
| 引脚 6 | PTA1 — Port A bit 1 (general-purpose I/O) |
| 引脚 7 | PTA2 — Port A bit 2 (general-purpose I/O) |
| 引脚 8 | PTA3 — Port A bit 3 (general-purpose I/O) |
| 引脚 9 | PTA4 — Port A bit 4 (general-purpose I/O) |
| 引脚 10 | PTA5/IRQ — Port A bit 5 / external interrupt request |
| 引脚 11 | PTA6 — Port A bit 6 (general-purpose I/O) |
| 引脚 12 | PTA7 — Port A bit 7 (general-purpose I/O) |
| 引脚 13 | VDD — Supply voltage (2.5 V or 3.3 V) |
| 引脚 14 | VSS — Ground |
| 引脚 15 | OSC1 — Oscillator input / external clock |
| 引脚 16 | OSC2 — Oscillator output |
| 引脚 17 | RST — Reset input (active low) |
| 引脚 18 | PTC0 — Port C bit 0 (general-purpose I/O) |
| 引脚 19 | PTC1 — Port C bit 1 (general-purpose I/O) |
| 引脚 20 | PTC2 — Port C bit 2 (general-purpose I/O) |
| 引脚 21 | PTC3 — Port C bit 3 (general-purpose I/O) |
| 引脚 22 | PTC4 — Port C bit 4 (general-purpose I/O) |
| 引脚 23 | PTC5 — Port C bit 5 (general-purpose I/O) |
| 引脚 24 | PTC6 — Port C bit 6 (general-purpose I/O) |
| 引脚 25 | PTC7 — Port C bit 7 (general-purpose I/O) |
| 引脚 26 | PTB4 — Port B bit 4 (general-purpose I/O) |
| 引脚 27 | PTB5 — Port B bit 5 (general-purpose I/O) |
| 引脚 28 | PTB6 — Port B bit 6 (general-purpose I/O) |
| 引脚 29 | PTB7 — Port B bit 7 (general-purpose I/O) |
| 引脚 30 | VDD — Supply voltage (2.5 V or 3.3 V) |
| 引脚 31 | VSS — Ground |
| 引脚 32 | TEST/VPP — Test mode / programming voltage |
典型应用
MC68HC908RF2CFA 适用于 6 应用s: Remote Keyless Entry (RKE) Transmitter, Security Key Fob Controller, Low-End RF Transmitter Module, Consumer Electronics Human-Interface Device, Battery-Powered Industrial Sensor Node, Legacy Appliance Control Board.
Remote Keyless Entry (RKE) Transmitter
The MC68HC908RF2CFA fits RKE transmitter designs because its 2 KB FLASH is sufficient for one-way rolling-code encryption routines, the 4 MHz core supports fast button-debounce handling, and the 12 GPIO pins map directly to lock/unlock/trunk/panic buttons. The internal oscillator eliminates the external crystal, shrinking the PCB so it fits inside a key-fob housing. Operating from 2.5 V or 3.3 V lets a single CR2032 cell power the entire transmitter without an LDO, and the HCMOS process keeps quiescent current low enough for multi-year shelf life. Compared with modern Cortex-M0 RF transmitters, the HC908 has lower code density but its small RAM/FLASH footprint suits cost-optimized aftermarket RKE SKUs.
推荐
Security Key Fob Controller
For one-way RF security key fobs, the MC68HC908RF2CFA integrates the HC08 core, FLASH, RAM, and GPIO needed to drive a companion transmitter such as the MAX1472. The 12 GPIO pins handle four to six buttons plus an LED indicator, and the 128-byte RAM is sufficient for stack plus rolling-code buffer. The internal oscillator trims BOM cost on a sub-USD retail key fob where every cent matters. Industrial temperature grade supports indoor/outdoor automotive environments from -40 C to +85 C, making the part qualified for unbuffered garage-door and aftermarket alarm fobs.
推荐
Low-End RF Transmitter Module
The MC68HC908RF2CFA acts as the baseband controller in sub-GHz or 315/433 MHz RF transmitter modules. The HC08 core encodes button-press data and modulates the transmitter enable pin, while the internal 4 MHz bus provides timing resolution sufficient for simple OOK/ASK protocols. The 2 KB FLASH stores button-mapping tables, encoder seeds, and protocol constants, and the 128-byte RAM buffers transmit frames. Surface-mount LQFP-32 plus internal oscillator lets the RF module ship as a single-side PCB with minimum component count, attractive for OEM integration into consumer devices.
推荐
Consumer Electronics Human-Interface Device
The MC68HC908RF2CFA suits low-end human-interface devices such as remote controls, simple appliance controllers, and IR/RF dongles. The HC08 core executes button-matrix scanning and protocol-encoding logic within 2 KB FLASH, while the 12 GPIO pins cover a 4x4 keypad matrix plus LED feedback. The internal oscillator and 32-LQFP surface-mount package enable compact PCB designs that fit inside slim remote housings. The 2.5 V/3.3 V supply range supports direct battery operation and eliminates the need for an external regulator, reducing overall BOM by 1-2 components.
推荐
Battery-Powered Industrial Sensor Node
For battery-powered industrial sensors (temperature, contact, occupancy), the MC68HC908RF2CFA provides low-power 8-bit processing with HCMOS technology, internal oscillator (no crystal leakage), and 2.5 V/3.3 V supply that matches a single lithium cell or two AA cells. The 128-byte RAM is sufficient for periodic sensor reads and short packet buffering. The 32-LQFP package supports automated SMT assembly for high-volume industrial sensor SKUs. Designers should plan to migrate to S08 or Kinetis E series for new sensor roadmaps because of the part's obsolete lifecycle status.
推荐
Legacy Appliance Control Board
The MC68HC908RF2CFA fits legacy appliance control boards (washers, microwave ovens, dishwashers) where the existing firmware base is HC08 and a redesign is not cost-justified. The 2 KB FLASH, 12 GPIO, and internal oscillator cover relay drivers, sensor inputs, and timer controls for basic appliance cycles. The 32-LQFP surface-mount package integrates into existing SMT assembly lines. For new appliance designs, evaluate MC9S08 or Kinetis E series for active lifecycle, additional memory, and broader tool support.
推荐
推荐产品汇总
工程参考数据： MC68HC908RF2CFA ——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 | MC68HC908RF2MFA | MC68HC908RF2CFB | MC68HC908JL8CFAE |
|---|---|---|---|---|
| Brand | NXP Semiconductors (Motorola legacy) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 32-LQFP (7x7 mm) | 32-LQFP (7x7 mm) - same | 32-LQFP - same | 32-LQFP - same |
| Program Memory | 2 KB FLASH | 2 KB FLASH | 2 KB FLASH | 8 KB FLASH |
| RAM | 128 bytes | 128 bytes | 128 bytes | 256 bytes |
| CPU Core | HC08 8-bit | HC08 8-bit | HC08 8-bit | HC08 8-bit |
| Bus Frequency | 4 MHz | 4 MHz | 4 MHz | 8 MHz |
| I/O Pins | 12 | 12 | 12 | 26 |
| Oscillator | Internal | Internal | Internal | Internal |
关键差异点
- Lowest-cost drop-in alternate with identical die （对比 MC68HC908RF2MFA)
- Family variant for legacy stock flexibility （对比 MC68HC908RF2CFB)
- Higher memory headroom in same LQFP family （对比 MC68HC908JL8CFAE)
设计说明
The MC68HC908RF2CFA operates from 2.5 V or 3.3 V at the VDD pins (13, 30). For battery-powered RKE key-fob designs, place a 100 nF decoupling capacitor close to each VDD pin and a 10 uF bulk capacitor on the battery side. Estimate standby current at sub-1 mA when the HCMOS core is halted and the internal oscillator is gated.
The 32-LQFP package has a 0.8 mm lead pitch. Per the manufacturer datasheet, allocate a copper pad area at least 0.4 mm x 0.4 mm for each gull-wing lead with the standard LQFP land pattern. Route the internal-oscillator traces (OSC1, OSC2) away from switching signals to minimize jitter. Leave the TEST/VPP pin accessible for in-circuit programming if field firmware updates are planned.
Common pitfalls when designing with MC68HC908RF2CFA: (1) Assume obsolete lifecycle - stock fluctuates and last-time-buy notices may apply; (2) Do not exceed 3.6 V on VDD as the HCMOS process has limited over-voltage tolerance; (3) Unused I/O pins must be configured as outputs (low) or inputs with internal pull-up enabled to minimize power consumption; (4) Do not rely on this part for new production without a verified second-source or NXP-approved migration path (S08 or Kinetis E).
合规信息
RoHS and REACH compliance status not stated in the provided verified web data; original Motorola/Freescale part predates current RoHS documentation standards. Part is industrial temperature grade but not AEC-Q100 qualified - not intended for automotive safety-critical applications.