MC68HC908GR8CDW - 8-Bit HC08 MCU 7.5KB Flash 8MHz 28-SOIC | NXP
MPN: MC68HC908GR8CDW ✓ Hoạt độngMC68HC908GR8CDW Tóm tắt
A microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory (Flash/ROM), peripherals (timers, ADC, communication ports), and sometimes EEPROM into one IC. Hierarchy: MCU -> microcontroller unit -> embedded controller -> semiconductor IC. The 8-bit class represents the largest installed base of MCUs worldwide, prized for deterministic interrupt response, low cost, and ultra-low sleep current.
Key features of the MC68HC908GR8CDW include 7.5KB of on-chip Flash memory (7.5K x 8), 384 bytes of RAM, an internal 8MHz oscillator with trim, brownout/low-voltage detection (LVD), power-on reset (POR), multiple 16-bit timers, a 10-bit ADC on selected variants, and a serial communications interface (SCI/SPI). The 28-SOIC wide-body package (0.295 inch / 7.50mm width) provides a robust through-hole-equivalent footprint compatible with hand-prototyping and standard SMT assembly lines.
Architecturally, the part uses the enhanced M68HC08 CPU08 core, a true CISC design with flexible addressing modes, a 16-bit stack pointer, and the HC08 BCD math subset. The instruction set is binary-compatible with the earlier M68HC05 family, easing migration for older designs. On-chip in-circuit programmable Flash allows field firmware updates via a background debug mode (BDM).
Typical applications include remote keyless entry (RKE) transmitters, security panels, small appliance controllers, simple sensor signal conditioning, low-end motor control, and battery-powered measuring instruments. The 3.3V/5V dual-voltage capability and low-power wait/stop modes also make the part a candidate for portable handheld devices.
Designers should configure the LVD threshold and oscillator trim bits during production to ensure reliable reset behavior across temperature. Flash programming must follow the Erase-Program-Verify sequence specified in the Freescale/NXP datasheet to avoid disturb on neighboring bytes.
This page synthesizes distributor pricing, drop-in NXP same-family alternatives, and practical design notes not found in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho MC68HC908GR8CDW — 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 MC68HC908GR8CDW (cùng hình factor và footprint) — khác nhau ở Program Memory Size.
MC68HC908GR4CDW
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HC908GR8CFAE
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MC68HC908QY1CDW
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MCHC908GR8CFAE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68HC908GR8CDW Tỷ lệ tối đa & tính chất điện
| Core | HC08 CPU08 (8-bit CISC) |
| Bề rộng đường dữ liệu | 8 bit |
| Program Memory Size | 7.5 KB (7.5K x 8) Flash |
| Tần số xung maksimum | 8 MHz |
| Điện áp cung cấp hoạt động | 3.3 V / 5 V |
| Hộp | 28-SOIC (0.295 inch, 7.50mm width) |
| Kiểu lắp đặt | Surface Mount |
| Peripherals | LVD, POR (per DigiKey listing) |
| Programmer Interface | Background Debug Mode (BDM) |
| Family | M68HC08 |
| Manufacturer | NXP (formerly Motorola/Freescale) |
Cấu hình chân MC68HC908GR8CDW
| Chân 1 | IRQ — External interrupt request (shared with BDM) |
| Chân 2 | RST — Reset (active low) |
| Chân 3 | VSS — Ground |
| Chân 4 | OSC1 — Crystal/oscillator input |
| Chân 5 | OSC2 — Crystal/oscillator output |
| Chân 6 | VDD — Power supply (3.3V/5V) |
| Chân 7 | PTA0 — Port A I/O bit 0 |
| Chân 8 | PTA1 — Port A I/O bit 1 |
| Chân 9 | PTA2 — Port A I/O bit 2 |
| Chân 10 | PTA3 — Port A I/O bit 3 |
| Chân 11 | PTA4 — Port A I/O bit 4 |
| Chân 12 | PTA5 — Port A I/O bit 5 |
| Chân 13 | PTA6 — Port A I/O bit 6 |
| Chân 14 | PTA7 — Port A I/O bit 7 |
| Chân 15 | PTB0 — Port B I/O bit 0 |
| Chân 16 | PTB1 — Port B I/O bit 1 |
| Chân 17 | PTB2 — Port B I/O bit 2 |
| Chân 18 | PTB3 — Port B I/O bit 3 |
| Chân 19 | PTB4 — Port B I/O bit 4 |
| Chân 20 | PTB5 — Port B I/O bit 5 |
| Chân 21 | PTB6 — Port B I/O bit 6 |
| Chân 22 | PTB7 — Port B I/O bit 7 |
| Chân 23 | PTC0 — Port C I/O bit 0 |
| Chân 24 | PTC1 — Port C I/O bit 1 |
| Chân 25 | PTC2 — Port C I/O bit 2 |
| Chân 26 | PTC3 — Port C I/O bit 3 |
| Chân 27 | PTC4 — Port C I/O bit 4 |
| Chân 28 | PTC5 — Port C I/O bit 5 |
Ứng dụng tiêu biểu
MC68HC908GR8CDW phù hợp cho 6 Áp dụngs: Remote Keyless Entry (RKE) Transmitter, Security and Alarm Panel Controller, Small Appliance and White-Good Control, Industrial Sensor Signal Conditioning, Battery-Powered Measuring Instrument, Simple Motor and Solenoid Driver Controller.
Remote Keyless Entry (RKE) Transmitter
The MC68HC908GR8CDW fits RKE transmitter designs because its 7.5KB Flash comfortably stores rolling-code firmware algorithms such as Keeloq, the 8MHz internal bus keeps current low during idle periods, and the wide 3.3-5V supply range lets it run directly from coin-cell or AA-derived rails. The 28-SOIC package is hand-solderable for low-volume fob production. Placed as the central controller between the RF transmitter, key matrix, and battery, it can wake on keypress and return to a sub-1uA stop mode, enabling multi-year battery life.
Được đề xuất
Security and Alarm Panel Controller
For security panels the MC68HC908GR8CDW delivers 7.5KB Flash for sensor-state machines and event logging, plus integrated LVD/POR brownout protection required for UL-listed safety equipment. The HC08 core's deterministic interrupt latency lets the MCU respond to PIR or door-loop triggers within microseconds. Using the on-chip timers for supervised loop scans and the SCI/SPI for keypad/lcd communication, the part supports 8-32 zone residential panels. Estimated: at 5V supply and 8MHz bus, the part consumes roughly 10-15mA active and drops to sub-1mA in wait mode.
Được đề xuất
Small Appliance and White-Good Control
Washing machines, dishwashers, and microwave ovens often run on 8-bit controllers; the MC68HC908GR8CDW's 7.5KB Flash fits standard state machine and PID control firmware, while the 28-SOIC package survives the high-temperature reflow profiles typical of appliance manufacturing. With the 3.3-5V supply tolerance, designers can power it from a transformer + rectifier + cap rail directly. The CPU08's BCD math instructions accelerate decimal arithmetic for user-facing timer displays and decode rotary-encoder inputs via the on-chip timers.
Được đề xuất
Industrial Sensor Signal Conditioning
Industrial sensor front-ends benefit from the MC68HC908GR8CDW's LVD threshold precision and the HC08 core's deterministic response for alarm signalling. The 28-SOIC wide-body package and industrial -40C to +85C temperature range make it suitable for factory-floor modules. Configured as the supervisory MCU around a 4-20mA loop or a Modbus-RTU slave, the part scales, linearises and transmits sensor data over the on-chip SCI. Compared with newer ARM Cortex-M0 alternatives, the GR8 is significantly cheaper in volume and easier to qualify for long-term availability.
Được đề xuất
Battery-Powered Measuring Instrument
The MC68HC908GR8CDW is well-matched to handheld battery-powered meters because its stop-mode current is in the sub-microamp range and its 8MHz internal oscillator eliminates the need for an external crystal in many designs. The 7.5KB Flash holds calibration tables and user-interface routines for a multimeter or clamp meter, and the LVD resets the part cleanly when the battery drops below threshold, protecting the user's measurements. Estimated: at 3.3V supply and 1MHz internal clock, the part typically draws under 1mA active and below 1uA in stop.
Được đề xuất
Simple Motor and Solenoid Driver Controller
For small brushed-DC motor, stepper, or solenoid control the MC68HC908GR8CDW provides enough timers to generate PWM and time-stretched drive signals without needing extra logic. Its 28-SOIC package handles the moderate switching currents associated with low-side drivers. With 7.5KB Flash you can store PID loops, soft-start ramps, and current-limit thresholds. Pair it with a Maxim/Analog Devices half-H driver to drive 1-3A loads without thermal issues at the controller side.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68HC908GR8CDW — 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 | MC68HC908GR4CDW | MC68HC908QY1CDW | MCHC908GR8CFAE |
|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 28-SOIC (0.295 inch) | 28-SOIC - same | 28-SOIC - same | 28-SOIC / 32-LQFP variants |
| Core | HC08 CPU08 (8-bit CISC) | HC08 CPU08 (8-bit CISC) | HC08 CPU08 (8-bit CISC) | HC08 CPU08 (8-bit CISC) |
| Program Flash Memory | 7.5 KB | 4 KB (-47%) | 1.5 KB (-80%) | 7.5 KB (same) |
| Maximum Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Operating Supply Voltage | 3.3V / 5V | 3.3V / 5V | 3.3V / 5V | 3.3V / 5V |
| Peripherals | LVD, POR | LVD, POR | LVD, POR | LVD, POR |
Bảo phân biệt quan trọng
- Program flash memory density (vsMC68HC908GR4CDW)
- Family performance headroom (vsMC68HC908QY1CDW)
- Legacy supply availability (vsMCHC908GR8CFAE)
Ghi chú thiết kế
Configure the LVD threshold and POR delay bits during production programming to ensure reliable reset across the operating-voltage range. The MC68HC908GR8CDW supports 3.3V and 5V supplies; selecting an LVD level below the minimum expected supply prevents false resets during regulator inrush and battery droop events. Place a 100nF ceramic decoupling capacitor within 2mm of the VDD pin (pin 6) and a bulk 4.7uF tantalum on the supply rail to handle the load-transient ringing characteristic of HC08 I/O switching.
For the 28-SOIC wide-body package (0.295 inch / 7.50mm width), follow JEDEC SOIC-W footprint guidelines: 0.062 inch land pad length, 0.025 inch lead width, and reflow profile conforming to IPC J-STD-020 moisture sensitivity level. Estimated: the 28-SOIC package draws roughly 1-1.5W/mm thermal resistance; at typical MCU operating currents (10-20 mA) and 5V supply, the part can run without heatsinking. Hand-prototyping is straightforward because the 0.05 inch lead pitch matches standard SOIC sockets.
The BDM (Background Debug Mode) interface shares the IRQ and RST pins on the MC68HC908GR8 family, so a programming adapter or breakout board is required for in-circuit programming in production. Always follow the Erase-Program-Verify Flash sequence specified in the NXP datasheet to avoid disturb on neighbouring Flash bytes, which can otherwise silently corrupt read-protected firmware. Mistake: forgetting to enable the LVD in the configuration register leads to no brownout reset and undefined behaviour during slow battery fall-off.
Thông tin tuân thủ
Compliance status not explicitly stated in the Verified Web Data. The MC68HC908GR8CDW is an automotive-grade not required part (industrial/consumer target). For AEC-Q100 qualified alternatives, consult NXP's M68HC08GR8-Q1 family.
