MC68HC908MR32CB - 32KB Flash 8-Bit MCU | NXP 56-SDIP Motor Control
MPN: MC68HC908MR32CB ✗ Cuối đờiMC68HC908MR32CB Tóm tắt
An 8-bit MCU such as the MC68HC908MR32CB is a single-chip computer that integrates CPU, RAM, non-volatile program memory, and peripheral I/O on one die. The 68HC08 line is part of the broader 8-bit microcontroller family used in cost-sensitive, deterministic real-time applications. Within the electronics taxonomy it sits under: MCU -> microcontroller unit -> embedded processor -> semiconductor. Competing architectures include the Microchip PIC16/PIC18 and the Atmel/Microchip AVR families, but the HC08 offers an in-application programmable Flash and a stable instruction set favored in industrial motor drive designs.
Key features include 32KB (32K x 8) Flash for user code, 768 bytes of on-chip SRAM for variables and stack, an internal oscillator that eliminates the need for an external crystal in many designs, and dedicated PWM outputs suitable for three-phase brushless DC motor commutation. The HC08 CISC instruction set simplifies code generation while maintaining deterministic cycle counts. The 56-SDIP through-hole package offers robust mechanical and thermal characteristics for industrial control hardware.
The architecture combines a 68HC08 CPU core with on-chip debug support, low-voltage detect, and multiple timer interfaces. The Flash array supports in-application reprogramming, enabling firmware upgrades in the field without removing the MCU from the board. The 768-byte RAM accommodates modest data buffers and stack frames typical of motor-control state machines.
Typical applications include single-phase and three-phase AC induction motor control, brushless DC (BLDC) and switched-reluctance drives, washing-machine and refrigerator compressor drivers, low-end variable-frequency drives, and industrial fans/pumps. The PWM architecture and 8 MHz throughput are tuned for direct control of small appliances.
When designing with this part, ensure decoupling capacitors are placed close to the VDD/VSS pins per the bypass guidance in the datasheet. Use high-frequency-response ceramics on power pins to suppress transient currents during PWM edge transitions, which would otherwise couple noise into adjacent analog rails.
This page synthesizes distributor stock data, pin-compatible substitutes, and practical design notes not compiled in the manufacturer's datasheet.
Bộ thay thế dễ dàng lắp đặt cho MC68HC908MR32CB — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với MC68HC908MR32CB (cùng hình factor và footprint) — khác nhau ở Core, RAM Size, Program Memory Size, Manufacturer, Number of I/O.
MC68HC908MR16CB
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC908MR32VBE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC908MR32CBE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC9S08MR32CLH
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HC908MR32CB Tỷ lệ tối đa & tính chất điện
| Core | 68HC08 (HC08 CISC) |
| Bề rộng đường dữ liệu | 8 bit |
| Program Memory Size | 32 KB (32K x 8) Flash |
| RAM Size | 768 bytes (768 x 8) |
| Number of I/O | 36 |
| Tần số xung maksimum | 8 MHz |
| Điện áp cung cấp | 5 V |
| Oscillator Type | Internal |
| Hộp / Vỏ | 56-SDIP (0.600 in / 15.24 mm) |
| Kiểu lắp đặt | Through-Hole |
| Peripheral Features | PWM, Timer, LVD |
| Packaging | Tube |
| Family | M68HC08 |
Cấu hình chân MC68HC908MR32CB
| Chân 1 | VSS — Ground reference |
| Chân 2 | VDD — 5 V supply input |
| Chân 3 | OSC1 — Oscillator input / external clock |
| Chân 4 | OSC2 — Oscillator output |
| Chân 5 | RESET — Active-low reset input |
| Chân 6 | IRQ — External interrupt request |
| Chân 7 | PTB0/TCH0 — I/O / timer channel |
| Chân 8 | PTB1/TCH1 — I/O / timer channel |
| Chân 9 | PTB2/TCH2 — I/O / timer channel |
| Chân 10 | PTB3/TCH3 — I/O / timer channel |
| Chân 11 | PTA0 — Port A I/O |
| Chân 12 | PTA1 — Port A I/O |
| Chân 13 | PTA2 — Port A I/O |
| Chân 14 | PTA3 — Port A I/O |
| Chân 15 | PTA4 — Port A I/O |
| Chân 16 | PTA5 — Port A I/O |
| Chân 17 | PTA6 — Port A I/O |
| Chân 18 | PTA7 — Port A I/O |
| Chân 19 | PTC0 — Port C I/O |
| Chân 20 | PTC1 — Port C I/O |
| Chân 21 | PTC2 — Port C I/O |
| Chân 22 | PTC3 — Port C I/O |
| Chân 23 | PTC4 — Port C I/O |
| Chân 24 | PTC5 — Port C I/O |
| Chân 25 | PTC6 — Port C I/O |
| Chân 26 | PTC7 — Port C I/O |
| Chân 27 | PWM0 — PWM output channel 0 |
| Chân 28 | PWM1 — PWM output channel 1 |
| Chân 29 | PWM2 — PWM output channel 2 |
| Chân 30 | PWM3 — PWM output channel 3 |
| Chân 31 | PWM4 — PWM output channel 4 |
| Chân 32 | PWM5 — PWM output channel 5 |
| Chân 33 | PWM6 — PWM output channel 6 |
| Chân 34 | PWM7 — PWM output channel 7 |
| Chân 35 | AN0 — ADC input / analog |
| Chân 36 | AN1 — ADC input / analog |
| Chân 37 | AN2 — ADC input / analog |
| Chân 38 | AN3 — ADC input / analog |
| Chân 39 | AN4 — ADC input / analog |
| Chân 40 | AN5 — ADC input / analog |
| Chân 41 | AN6 — ADC input / analog |
| Chân 42 | AN7 — ADC input / analog |
| Chân 43 | AVSS — Analog ground |
| Chân 44 | AVDD — Analog supply |
| Chân 45 | VREFH — ADC voltage reference high |
| Chân 46 | VREFL — ADC voltage reference low |
| Chân 47 | TDATA — SCI/serial transmit data |
| Chân 48 | RDATA — SCI/serial receive data |
| Chân 49 | SCLK — Serial clock |
| Chân 50 | PTD0 — Port D I/O |
| Chân 51 | PTD1 — Port D I/O |
| Chân 52 | PTD2 — Port D I/O |
| Chân 53 | PTD3 — Port D I/O |
| Chân 54 | PTD4 — Port D I/O |
| Chân 55 | PTD5 — Port D I/O |
| Chân 56 | PTE0 — Port E I/O |
Ứng dụng tiêu biểu
MC68HC908MR32CB phù hợp cho 6 Áp dụngs: Three-Phase BLDC Motor Drive, Single-Phase Induction Motor Control, Refrigerator and Washing-Machine Compressor Drivers, Industrial Fan and Pump Variable-Frequency Drives, Switched-Reluctance Motor Control, Low-End Servo and Stepper Motor Controllers.
Three-Phase BLDC Motor Drive
The MC68HC908MR32CB's integrated PWM channels and timer interface make it well suited to three-phase brushless DC (BLDC) motor commutation. With 8 MHz bus speed and 32 KB Flash, the firmware fits a complete state machine, commutation lookup table, and PI speed loop. The 768-byte RAM covers feedback samples and the control loop, while 36 I/O pins drive three half-bridge gate signals plus hall-sensor or back-EMF inputs. The HC08 CISC core offers deterministic 125 ns cycle time, which lets the MCU synchronize commutation with low jitter.
Được đề xuất
Single-Phase Induction Motor Control
Single-phase AC induction motor controllers rely on triac or IGBT commutation timed via PWM and zero-cross detection. The MC68HC908MR32CB's 8 MHz throughput handles phase-angle control and soft-start ramps in real time. The 32 KB Flash comfortably hosts FIR-filtered mains frequency measurement and adaptive torque curves. The 56-SDIP package is convenient for through-hole motor-driver PCBs, where mechanical robustness is critical. With 36 I/O, the device manages user interfaces, supply monitoring, and triac firing logic.
Được đề xuất
Refrigerator and Washing-Machine Compressor Drivers
Domestic appliance compressor drivers benefit from the MC68HC908MR32CB's combination of Flash memory for adaptive compressor algorithms and PWM for inverter-style variable-frequency drive. The 56-SDIP through-hole package suits the high-vibration, high-humidity environment of white-goods appliance electronics. With 8 MHz bus speed, the MCU drives inverter switches at up to several kHz switching frequency while still managing UART service, sensor sampling, and safety shutdown logic on a single chip.
Được đề xuất
Industrial Fan and Pump Variable-Frequency Drives
Low-power variable-frequency drives for industrial fans and pumps integrate well with the MC68HC908MR32CB's HC08 core. The 32 KB Flash hosts current-loop and voltage-control algorithms, while the integrated timers provide accurate carrier-frequency synthesis. The 768-byte SRAM supports per-cycle current samples without needing external memory. The 36 I/O pins connect to current sensors, gate drivers, fault inputs, and command interfaces typically required in 1-2 horsepower industrial drives.
Được đề xuất
Switched-Reluctance Motor Control
Switched-reluctance drives for small traction or industrial applications map cleanly onto the MC68HC908MR32CB's PWM architecture. With 36 I/O lines, the MCU can directly control four-phase stator windings through external gate drivers. The deterministic 8 MHz instruction cycle supports rotor-position decoding and energy-optimization commutation. The 32 KB Flash accommodates rotor-mapping tables and torque-shaping algorithms, while 768 bytes RAM provides operating headroom for interrupt-driven service routines.
Được đề xuất
Low-End Servo and Stepper Motor Controllers
Stepper and low-power servo controllers are an economic application for the MC68HC908MR32CB. The 8 MHz core sequences phase-step tables in real time, while the Flash stores S-curve acceleration profiles. With 36 I/O, the MCU drives up to four steppers using H-bridges, plus a UART or I/O interface for command. The internal oscillator eliminates the external crystal in many designs, and the 56-SDIP package is straightforward to hand-prototype during product development of small automation hardware.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68HC908MR32CB — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | MC68HC908MR16CB | MC908MR32VBE | MC908MR32CBE | MC9S08MR32CLH |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 56-SDIP (0.600 in) | 56-SDIP (0.600 in) | 56-PSDIP (0.600 in) | 56-PSDIP (0.600 in) | LQFP-64 |
| Core | 68HC08 (CISC) | 68HC08 (CISC) | 68HC08 (CISC) | 68HC08 (CISC) | HCS08 (modern variant) |
| Program Flash | 32 KB | 16 KB (-50%) | 32 KB | 32 KB | 32 KB |
| RAM | 768 B | 768 B | 768 B | 768 B | 768 B |
| Max Clock | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8-16 MHz |
| I/O Pins | 36 | 36 | 36 | 36 | 44 (LQFP-64) |
| Mounting Type | Through-Hole | Through-Hole | Through-Hole | Through-Hole | Surface Mount |
| Lifecycle | Obsolete / Last Time Buy | Obsolete | Production (legacy) | Production (legacy) | Active (recommended for new designs) |
Bảo phân biệt quan trọng
- Specifically architected PWM for motor control (vsMC68HC908MR16CB)
- Same die, alternative orderable suffix (vsMC908MR32VBE / MC908MR32CBE)
- Drop-in for legacy motor boards with active production status (vsMC9S08MR32CLH)
Ghi chú thiết kế
Decoupling critical: place a 0.1 uF high-frequency ceramic on each VDD/AVDD pair directly adjacent to the pins, and use the optional bulk current bypass (C2) on the main supply per Figure 1-4 of the NXP datasheet. The 68HC08 core draws sharply pulsed currents at the bus clock edge; without sufficient local decoupling, these current spikes can couple into analog inputs and disrupt ADC readings.
Keep the AGND/AVDD analog reference traces clean: separate analog supply ground from noisy digital ground by routing return currents thoughtfully on the PCB, and avoid running PWM switching traces under the crystal/clock traces. The 56-SDIP footprint is favorable for hand-prototyping motor-control boards; pin 1 is at top-left with the notch up per standard DIP convention.
Use the HC08's low-voltage detect (LVD) module to force a known-good reset under VDD sag conditions, since motor-drive supplies can droop sharply during PWM transition or DC-bus overload. Do not assume the internal oscillator is precise enough for serial communication: configure SCI to a baud rate the oscillator can reliably hit under all operating conditions, or supply an external crystal if UART timing is critical.
At 8 MHz with PWM edge rates in the kHz-MHz range, keep PWM trace lengths short and avoid ground-star separation. Series damping resistors (~22-33 ohm) on gate-driver outputs reduce ringing when the MCU drives a capacitive load directly. Adequate guard-band around the analog reference pins preserves ADC accuracy for feedback signals.
Thông tin tuân thủ
Compliance flags are not present in the verified web-data snippets. Confirm directly with NXP or your franchised distributor at order entry. The 56-SDIP through-hole package and 68HC08 legacy status are relevant context for compliance reviews.
