MC908JB8JDWE - HC08 8-bit MCU, 8KB Flash, 20-SOIC | NXP
MPN: MC908JB8JDWE ✗ Cuối đờiMC908JB8JDWE Tóm tắt
An 8-bit microcontroller is a single-chip computer that integrates a processor core, program memory, data RAM, and peripherals such as timers, serial interfaces, and I/O ports on one die. Within the power-management and control hierarchy of an embedded system, an MCU sits between discrete logic and higher-performance 16/32-bit processors, handling sequential control tasks, human-interface functions, and simple communication protocols. The M68HC08 family from Freescale (now NXP) is a low-cost, high-performance lineage based on the enhanced CPU08 CISC core.
Key features of the MC908JB8JDWE include the CPU08 core with CISC instruction set, 8 KB of in-system-programmable Flash, 256 bytes of RAM, a full-speed USB device port that made the JB8 sub-family popular for low-speed human interface devices, and up to 20 pins of general-purpose and specialized I/O in the compact SOIC footprint.
Architecturally, the device belongs to the HC08JB family, which NXP designed specifically around the USB device peripheral. The Flash memory allows field reprogramming through the monitor ROM, while the HC08 core executes efficient 8-bit arithmetic and indexed addressing suitable for firmware loops and protocol handling. The wide SOIC body eases hand soldering and in-circuit probing during development.
Typical applications include USB HID peripherals such as mice, keyboards, and game controllers; small appliance and consumer device control; battery chargers and instrumentation front ends; and legacy embedded systems that already use the HC08 toolchain.
A key design consideration is that this part is End-of-Life per the official NXP product page, so new designs should evaluate alternatives, and existing production should secure last-time-buy inventory or qualify a drop-in HC08 family substitute.
This page synthesizes distributor listing data, official NXP product information, and cross-reference analysis including drop-in alternatives and lifecycle guidance not found on the manufacturer datasheet alone.
Bộ thay thế dễ dàng lắp đặt cho MC908JB8JDWE — 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 MC908JB8JDWE (cùng hình factor và footprint) — khác nhau ở Package, Program Memory Size, ADC, Operating Temperature, Supply Voltage.
MC908JB16DWE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68HC908LB8CDWE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC908JL8CDWE
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC908JB8JDWE Tỷ lệ tối đa & tính chất điện
| Core Processor | HC08 (CPU08) |
| Core Size | 8-Bit |
| Instruction Set | CISC |
| Maximum Clock / Bus Speed | 3 MHz |
| Program Memory Type | Flash |
| Program Memory Size | 8 KB (8K x 8) |
| RAM Size | 256 bytes |
| Điện áp cung cấp | 5 V |
| Special Peripherals | USB device interface (HC08JB family) |
| Số lượng chân | 20 |
| Hộp | 20-SOIC W (wide body) |
| Kiểu lắp đặt | Surface Mount |
| Packaging | Tube / Rail |
| Product Series | MC68HC908JB8 SERIES (HC08JB) |
| Programmable Verification | Not Verified (per distributor data) |
Hướng dẫn cấu hình chân MC908JB8JDWE 20-soic w (wide body)
Cấu hình chân cho MC908JB8JDWE (20-soic w (wide body) 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 MC908JB8JDWE.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
MC908JB8JDWE phù hợp cho 6 Áp dụngs: USB HID Peripherals, Small Appliance and Consumer Device Control, Battery Charger Control, Legacy Embedded System Sustainment, Instrumentation Front Ends, Educational and Legacy Firmware Porting.
USB HID Peripherals
The MC908JB8JDWE fits USB human-interface device designs because its HC08JB sub-family integrates a dedicated USB device peripheral on the CPU08 core, eliminating an external USB interface chip that a generic HC08 would require. In a mouse or keyboard, the MCU enumerates as a HID-class device over the on-chip USB port while the 8 KB Flash stores the report-descriptor and state-machine firmware, and the 256-byte RAM buffers endpoint traffic. The 3 MHz bus is sufficient for polled HID report rates. Design consideration: the 5 V supply matches legacy USB bus power, but new USB designs should prefer a current-generation MCU with USB-IF compliant PHY support.
Được đề xuất
Small Appliance and Consumer Device Control
For coffee makers, fans, chargers, and toys, the MC908JB8JDWE provides sequential control in a minimal 20-pin footprint. The CPU08 CISC core executes the control loops and button-debounce logic, the 8 KB Flash holds the application firmware with headroom for a small state machine, and the general-purpose I/O available on the 20-SOIC W pins drives LEDs, relays, and reads switches. Because the device operates from a single 5 V supply, it connects directly to legacy transformer-based power stages without an additional regulator. Design consideration: the 3 MHz bus caps processing throughput, so interrupt-driven timing should be kept simple, and EOL status means existing products should secure stock or qualify a family alternative.
Được đề xuất
Battery Charger Control
In NiMH and Li-ion charger products of its era, the HC08JB8 handled charge-termination algorithms, timer supervision, and LED status indication. The 8 KB Flash stores the charging profile tables and termination criteria, the CPU08 core evaluates voltage and current feedback at the 3 MHz bus rate, and the on-chip USB device option additionally allows the charger to report status to a host PC - a differentiator over non-USB HC08 variants. The 5 V supply tolerates typical wall-adapter inputs with simple regulation. Design consideration: verify the exact ADC channel count on this suffix in the datasheet before relying on analog feedback channels.
Được đề xuất
Legacy Embedded System Sustainment
The most common current use of the MC908JB8JDWE is sustaining shipping products whose firmware is locked to the HC08 toolchain. Its value here is architectural continuity: the CPU08 instruction set, monitor ROM programming method, and 20-SOIC W footprint allow direct board population without redesign. Procurement teams use it for last-time-buy stock and spare replenishment, while engineering teams validate incoming parts against the family datasheet electrical tables. Design consideration: because NXP marks the part End-of-Life, build a buffer stock strategy and document the MC68HC908LB8CDWE or MC908JB16DWE as pre-qualified backup sources with verified pin mapping.
Được đề xuất
Instrumentation Front Ends
Simple bench and portable instruments of the HC08 era used the MC908JB8JDWE for front-panel control and result formatting: the 8 KB Flash holds menu and display routines, the CPU08 core handles scaling arithmetic, and the USB device peripheral - unique to the JB sub-family among low-cost HC08 parts - streams readings to a PC without a separate USB-UART bridge. The 5 V logic level directly interfaces legacy CMOS analog front ends. Design consideration: at a 3 MHz bus, keep display refresh and communication ISRs short, and confirm on-chip ADC availability on this suffix before connecting analog signals.
Được đề xuất
Educational and Legacy Firmware Porting
Universities and repair shops use the MC908JB8JDWE to teach 8-bit embedded fundamentals on real silicon: the CPU08 CISC instruction set is fully documented in the M68HC08 family literature, the Flash is reprogrammable through the on-chip monitor ROM, and the wide 20-SOIC W package is easy to socket and probe on a breadboard adapter. The 256-byte RAM teaches disciplined memory budgeting. When porting legacy HC08 code to modern parts, this device serves as the reference platform for behavioral regression testing, ensuring the ported firmware reproduces the original timing on pins before hardware migration.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC908JB8JDWE — 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 | MC908JB16DWE | MC68HC908LB8CDWE | MC908JL8CDWE |
|---|---|---|---|---|
| Package | 20-SOIC W | 20-SOIC W - same | 20-SOIC W - same | 20-SOIC W - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | HC08 (CPU08) 8-bit CISC | HC08 (CPU08) 8-bit CISC | HC08 (CPU08) 8-bit CISC | HC08 (CPU08) 8-bit CISC |
| Flash Memory | 8 KB (8K x 8) | 16 KB | 8 KB (8K x 8) | 8 KB |
| USB Device Peripheral | Yes (HC08JB family) | Yes (HC08JB family) | No (LB sub-family) | No (JL sub-family) |
Bảo phân biệt quan trọng
- Integrated USB device peripheral (vsMC68HC908LB8CDWE)
- Largest firmware headroom in family comparison (vsMC908JB8JDWE itself vs MC908JB16DWE)
- Guaranteed toolchain continuity (vsMC908KX8CPE)
Ghi chú thiết kế
This part is End-of-Life according to the official NXP product page. Do not start new designs with it. For sustaining production, place a last-time-buy covering expected service life plus attrition, and pre-qualify a backup device from the same HC08 family (MC68HC908LB8CDWE or MC908JB16DWE) by verifying the pin-function map against the family datasheet, since peripheral allocation differs between the JB, LB, and JL sub-families even within the same 20-SOIC W footprint.
The device operates from a 5 V supply per distributor comparison data. Decouple VDD with a 0.1 uF ceramic capacitor placed as close to the supply pin as possible, and add bulk capacitance (4.7 uF to 10 uF) at the board entry point. If the design uses the USB device peripheral, ensure the 5 V rail is clean enough to meet USB signaling levels and follow the family datasheet recommendations for USB pull-up and ESD protection on the D+/D- lines.
The 20-SOIC W wide-body footprint uses a 1.27 mm lead pitch. Include编程 the standard SOIC-20 land pattern with slightly elongated pads to allow visual inspection of all 20 joints, and add test points on the monitor-mode entry pins so production programming fixtures can access the Flash monitor ROM. Keep the oscillator traces short and guarded, since the 3 MHz system clock accuracy directly affects USB timing on JB-family parts.
On the HC08JB family, the USB D+/D- lines are sensitive to stub length and mismatch. Route them as a short, matched pair (targeting 90 ohm differential where the two-layer stackup allows), keep total length under a few centimeters, and place the series/termination components from the family datasheet reference circuit near the connector. Avoid routing D+/D- parallel to switching loads such as relay coils or LED drivers sharing the same 5 V rail.
Thông tin tuân thủ
Compliance status not stated in the retrieved web data; NXP product page shows an Environmental Quality section but its contents were not included in the search results. Verify on the official NXP part page before procurement.
