MC68HC908LB8CDWE - 8-Bit 8MHz MCU 8KB Flash 20-SOIC | NXP
MPN: MC68HC908LB8CDWE ✗ Cuối đờiMC68HC908LB8CDWE Tóm tắt
An 8-bit microcontroller (MCU) is a complete computing system on a single chip, combining a processor core, program memory, data memory, and peripherals. MCUs sit at the device level of the embedded-system hierarchy: microcontroller -> embedded processor -> semiconductor IC. The HC08 family is Freescale's enhanced successor to the classic 68HC05 architecture, object-code upward compatible and widely used in cost-sensitive embedded control.
Key features of the MC68HC908LB8CDWE include the HC08 CISC core executing at 8 MHz with efficient instruction throughput, 8KB in-system-programmable FLASH program memory eliminating masked-ROM lead times for low-volume designs, and 18 configurable I/O pins providing near-total pin utilization of the 20-pin package. On-chip LVR and POR circuits guarantee deterministic startup behavior during brown-out and power-up events without external supervisor ICs.
Technically, the part implements the HC08 core with 16-bit addressing, a stack pointer, and indexed addressing modes suited to C compilation. The FLASH memory supports field reprogramming, which simplifies firmware updates in serviced products. PWM capability supports lamp dimming, small motor drive, and buzzer tone generation directly from the MCU pins.
Typical applications include small appliance control, automotive body accessories, LED and lamp ballast control, and low-cost industrial sensing nodes where the PWM outputs and flash reprogrammability reduce system BOM count.
When designing with this MCU, note that the part is listed as obsolete: NXP no longer manufactures it, and current channel supply comes from remaining distribution stock and authorized aftermarket sources such as Rochester Electronics. New designs should target the MC9S08 or MC9S12 families.
This page synthesizes distributor pricing, lifecycle status, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a complete sourcing and design picture for this legacy 8-bit microcontroller.
Bộ thay thế dễ dàng lắp đặt cho MC68HC908LB8CDWE — 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 MC68HC908LB8CDWE (cùng hình factor và footprint) — khác nhau ở Package, Program Memory Size, RAM Size, Core Processor, Supply Voltage.
MC68HC908LB8VDWE
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MC68HC908LB8MDWE
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →MC908QB8CDWE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68HC908LB8CDWE Tỷ lệ tối đa & tính chất điện
| Core Processor | HC08 |
| Core Size | 8-Bit |
| Maximum Clock Speed | 8 MHz |
| Program Memory Size | 8KB (8K x 8) |
| Program Memory Type | FLASH |
| RAM Size | 128 x 8 |
| EEPROM Size | - |
| Number of I/O | 18 |
| Peripherals | LVR, POR, PWM |
| Connectivity | - |
| Hộp | 20-SOIC (0.295 inch, 7.50 mm Width) |
| Kiểu lắp đặt | Surface Mount |
| Series | HC08 |
| Part Status | Obsolete |
Hướng dẫn cấu hình chân MC68HC908LB8CDWE 20-soic (0.295 inch, 7.50 mm width)
Cấu hình chân cho MC68HC908LB8CDWE (20-soic (0.295 inch, 7.50 mm width) gói). IC số này bao gồm chân GPIO, giao diện truyền thông (UART, SPI, I2C) và chân nguồn. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết các chức năng chân thay thế và tùy chọn cấu hình. Cực kỳ quan trọng cho thiết kế hệ thống tích hợp và lập trình PCB.
Không có dữ liệu chân cụ thể sẵn có cho MC68HC908LB8CDWE.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
MC68HC908LB8CDWE phù hợp cho 6 Áp dụngs: Small Appliance Control, LED and Lamp Ballast Control, Automotive Body Accessories, Low-Cost Industrial Sensing Nodes, Battery-Powered Handheld Devices, Legacy Product Maintenance and Repair.
Small Appliance Control
The MC68HC908LB8CDWE fits small appliance control boards (blenders, coffee makers, fans) where its 18 I/O lines drive buttons, LEDs, relays, and buzzers directly from a single 20-SOIC chip. The integrated PWM peripheral generates tone or heater duty-cycle control without external timer ICs, while on-chip LVR and POR guarantee deterministic resets on unstable mains-derived supplies. Its 8KB FLASH supports in-system firmware updates during appliance service, cutting recall costs versus masked-ROM predecessors. At 8 MHz the HC08 core comfortably runs keypad scanning and state-machine control loops. Because the device is obsolete, appliance makers should secure aftermarket stock or migrate the footprint to the MC9S08 family.
Được đề xuất
LED and Lamp Ballast Control
Lamp ballast and LED driver boards benefit from the MC68HC908LB8CDWE's PWM output, which directly sets brightness or switching duty cycle from the MCU pin with no external PWM controller. The 20-SOIC package with 18 I/O accommodates dimming interfaces, fault feedback inputs, and relay or TRIAC drive signals in one chip. The Low-Voltage Reset module prevents undefined TRIAC gating during brown-out, an important safety consideration in mains-connected lighting. The 8KB FLASH allows field retuning of dimming curves after regulatory changes. Supply in the legacy HC08 line is constrained since the part is obsolete, so new ballast platforms should target MC9S08 equivalents while existing boards can use remaining stock.
Được đề xuất
Automotive Body Accessories
The MC68HC908LB8 family, including the extended-temperature V and M grades in the same 20-SOIC DW package, was widely used in automotive body-electronics modules such as mirror adjusters, seat memory, and lamp modules. The 18 I/O lines drive motors, lamps, and switches; PWM supports soft-start lamp dimming; and LVR/POR protect against crank-related supply dips during engine start. The 8KB FLASH allows end-of-line calibration data and firmware updates. Commercial-grade C-suffix parts are suitable only for cabin zones; the V grade (-40 to +85 C) covers under-hood-adjacent locations. Select the M-grade drop-in variant for harsher automotive thermal environments.
Được đề xuất
Low-Cost Industrial Sensing Nodes
Simple industrial sensors and limit-switch nodes use the MC68HC908LB8CDWE to condition inputs, debounce contacts, and drive 4-20 mA style outputs via PWM plus external filtering. The 8 MHz HC08 core handles averaging and thresholding routines within its 8KB FLASH and 128-byte RAM budget. LVR and POR provide safe power-up behavior in electrically noisy factory environments, while the surface-mount 20-SOIC withstands vibration better than DIP alternatives. FLASH programmability lets OEMs tune thresholds per installation without hardware changes. Given the obsolete status, integrators maintaining installed bases should qualify the aftermarket source or prepare a MC9S08-based footprint migration for future production runs.
Được đề xuất
Battery-Powered Handheld Devices
Handheld meters, remote controls, and portable instruments leverage the MC68HC908LB8CDWE's small 20-SOIC footprint and HC08 core efficiency to implement button scanning, display driving, and simple measurement sequencing from a compact BOM. The MCU's on-chip FLASH enables last-calibration-date storage and field firmware updates through a service fixture. The Low-Voltage Reset module prevents erratic behavior as the battery discharges toward the supply floor - a common failure mode in portable products. The 18 I/O lines directly drive segment displays and status LEDs without expansion logic. Verify the exact supply voltage floor against the datasheet before finalizing the battery chemistry and cutoff threshold in your design.
Được đề xuất
Legacy Product Maintenance and Repair
Service organizations repairing HC08-based legacy equipment use the MC68HC908LB8CDWE as a board-level replacement where masked ROM or OTP predecessors failed. Because the '908 flash part is firmware-compatible within the LB8 family and pin-identical across the C, V, and M temperature grades, technicians can substitute available grades within the same 20-SOIC footprint after confirming the operating environment temperature. The 8KB FLASH allows re-implementing or updating firmware dumped from surviving units, extending equipment life beyond OEM support. Sourcing relies on distribution remainders and the Rochester Electronics aftermarket; verify date codes and program each replacement before installation.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68HC908LB8CDWE — 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 | MC68HC908LB8VDWE | MC68HC908LB8MDWE | MC908QB8CDWE |
|---|---|---|---|---|
| Package | 20-SOIC (0.295 in, 7.50 mm Width) | 20-SOIC (7.50 mm Width) - same | 20-SOIC (7.50 mm Width) - same | 16-SOIC - different footprint |
| Brand | NXP Semiconductors (Freescale) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | HC08, 8-Bit | HC08, 8-Bit | HC08, 8-Bit | HC08, 8-Bit |
| Clock Speed | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Flash Memory | 8KB (8K x 8) | 8KB (8K x 8) | 8KB (8K x 8) | 8KB (8K x 8) |
| Operating Temperature | 0C to +70C (C grade) | -40C to +85C (V grade) | -40C to +125C class (M grade) | 0C to +70C (C grade) |
Bảo phân biệt quan trọng
- Highest I/O density in its HC08 class (vsMC908QB8CDWE)
- Extended-temperature drop-in variants available in identical footprint (vsMC68HC908LB8MDWE)
- FLASH program memory instead of masked ROM (vsMC68HC705J1ACP)
Ghi chú thiết kế
The MC68HC908LB8CDWE is obsolete. All supply now comes from residual distribution stock and the authorized aftermarket (Rochester Electronics lists it on DigiKey). Before committing a repair or bridge-production run, verify stock quantity, date codes, and whether parts are factory-new or reclaimed. Do not design new products around this MPN - NXP's supported successor path is the MC9S08 family, which requires firmware porting and typically a PCB footprint change.
Use the on-chip Low-Voltage Reset (LVR) and Power-On Reset (POR) as the primary reset mechanism, but confirm the actual Vcc operating range in the manufacturer datasheet before finalizing your supply rail and brown-out margin, since distributor listings did not publish this parameter. Decouple Vcc with a 0.1 uF ceramic capacitor placed within a few millimeters of the supply pin, plus bulk capacitance if driving relays or lamps from adjacent circuitry on the same rail.
The DW suffix denotes a wide-body 20-SOIC with 7.50 mm body width - confirm your land pattern is the wide SOIC (about 10.3 mm span) and not the narrow 3.9 mm SOIC used by 16-pin Q-family parts. Keep PWM output traces away from the oscillator and analog inputs to limit radiated and conducted coupling. With 18 of 20 pins as I/O, plan test points on unused configurations early, since rework access on 1.27 mm pitch SOIC pins is limited.
Monitor-mode FLASH programming requires specific pin conditions at reset entry; the exact entry procedure is documented in the M68HC08 family datasheet. When reprogramming parts in fixtures for legacy repairs, verify that your programmer still supports the HC08 monitor protocol - many modern programmers have dropped legacy HC08 support. Always blank-check flash parts before writing, as reclaimed aftermarket stock may contain prior-use firmware.
Thông tin tuân thủ
Compliance status was not published in the retrieved distributor data for this legacy part; original HC08-era production predates modern RoHS marking conventions in some date codes. Verify with the manufacturer or aftermarket supplier per date code.
