MC908JB8FBE - 8-Bit HC08 MCU, 8KB Flash, 44-QFP | NXP
MPN: MC908JB8FBE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.24 | $3.24 |
| 10 | $3.08 | $30.80 |
| 100 | $2.92 | $292.00 |
| 500 | $2.78 | $1,390.00 |
| 1,000 | $2.65 | $2,650.00 |
MC908JB8FBE Overview
An 8-bit MCU is a microcontroller whose data bus width is 8 bits, combining a processor core, program memory, data RAM, and peripheral functions on a single die. Within the system hierarchy, the M68HC08 family sits under Freescale's HC08 architecture, itself an upward-compatible evolution of the earlier 68HC05 family, and belongs to the broader category of embedded microcontrollers used for cost-sensitive control tasks.
Key features of the MC908JB8FBE include the low-cost, high-performance HC08 core, 8KB in-system-programmable FLASH program memory that replaces OTP or ROM for firmware updates, and the low-power design philosophy characteristic of the 908JB family. The JB family members integrate USB-oriented peripherals, making them historically popular for low-speed USB human interface devices such as mice, keyboards, and game controllers.
Technically, the HC08 core executes the M68HC05-compatible instruction set with added index-register stack addressing, a multiply instruction, and enhanced memory addressing, allowing compact code for control loops. The FLASH memory simplifies field upgrades and reduces inventory risk compared with masked-ROM alternatives. Clocking at 3 MHz maximum internal bus frequency keeps EMI low and timing design straightforward.
Typical applications include legacy USB peripheral devices, small appliance control, low-cost industrial sensing and actuation, and maintenance replacement of MCUs in existing PCB designs that were laid out around the 44-QFP footprint.
Design consideration: this part is a legacy 5V-supply device; verify availability and consider a socket-compatible or firmware-compatible migration path for new designs, since newer MCUs are typically 3.3V and smaller packages.
This page synthesizes verified distributor pricing, stock signals, and lifecycle context for the MC908JB8FBE not consolidated in the manufacturer documentation.
Drop-in alternatives for MC908JB8FBE — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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MC68HC908JB8FBE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC908JB8FBE Maximum Ratings & Electrical Characteristics
| Core Processor | HC08 |
| Core Architecture | 8-Bit CISC |
| Processor Series | HC08JB |
| Maximum Clock Frequency | 3 MHz |
| Data Bus Width | 8 bit |
| Program Memory Type | FLASH |
| Program Memory Size | 8KB (8K x 8) |
| Supply Voltage | 5 V |
| Package Type | 44-QFP (10 x 10 mm) / PQFP |
| Number of Pins | 44 |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Product Family | M68HC08 (908JB family) |
| Manufacturer | Freescale Semiconductor (now NXP USA Inc.) |
MC908JB8FBE 44-qfp (10 x 10 mm) / pqfp Pin Configuration Guide
Pin configuration for MC908JB8FBE (44-qfp (10 x 10 mm) / pqfp package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for MC908JB8FBE.
Refer to the datasheet for full pin configuration.
Typical Applications
MC908JB8FBE is suitable for 6 applications: Low-Speed USB Peripheral Devices, Small Appliance and Consumer Product Control, Industrial Sensor and Actuation Control, Legacy Board Repair and Life Extension, Low-Cost Embedded Prototyping and Education, Battery-Powered and Handheld Accessories.
Low-Speed USB Peripheral Devices
The 908JB family was designed around low-speed USB connectivity, and the MC908JB8FBE fits mice, keyboards, joysticks, and other USB HID products. Its HC08 core at 3 MHz provides enough throughput to handle USB low-speed signaling and HID report generation, while the 8KB FLASH program memory accommodates the USB enumeration stack and application logic with headroom for firmware tuning. Because program memory is FLASH rather than ROM, manufacturers can update device firmware during production or via field updates, correcting enumeration bugs without changing hardware. The 5V supply aligns with USB bus power, simplifying power architecture. For legacy USB accessories still in service, this MCU remains the firmware- and hardware-compatible heart of the design.
Recommended
Small Appliance and Consumer Product Control
Cost-sensitive consumer products such as kitchen appliances, fans, and small heaters benefit from the MC908JB8FBE's low-cost HC08 architecture and single-chip integration. The 8-bit CISC core at 3 MHz executes compact control loops for button scanning, LED indication, and relay or triac timing, while the 8KB FLASH memory stores the full application without external memory. The 44-pin QFP (10 x 10 mm) package provides enough I/O for keypads, indicators, and load drivers on a two-layer PCB, keeping system cost low. FLASH program memory allows one firmware image to serve multiple product variants, reducing inventory complexity. The 5V supply matches the transformer-derived power rails common in mains-powered appliances, avoiding extra regulators.
Recommended
Industrial Sensor and Actuation Control
In industrial settings, the MC908JB8FBE serves as a compact controller for sensor polling, threshold comparison, and actuator driving in products such as small pumps, valves, and monitoring nodes. The HC08 core's deterministic 8-bit execution suits fixed-cycle control loops, and the 3 MHz bus frequency keeps radiated emissions low for equipment passing industrial EMC checks. The 8KB FLASH program memory supports communication routines, calibration tables, and state-machine logic, and can be reprogrammed on the assembled board for firmware corrections. The 44-QFP package's I/O count handles multiple digital inputs, outputs, and status lines. Its 5V supply matches the classic industrial 5V logic rails still present in many legacy control cabinets and PCB designs.
Recommended
Legacy Board Repair and Life Extension
The primary modern role of the MC908JB8FBE is maintaining products whose PCBs were designed around the 44-QFP HC08JB8 footprint. Repair depots and contract manufacturers servicing discontinued industrial controls, USB accessories, and consumer electronics need authentic replacement MCUs to avoid board redesign. Because the part is FLASH-based, a replacement can be programmed with the original firmware image before or after installation, restoring full functionality without reproducing mask-ROM masks. Sourcing from reputable distributors with date-code verification protects against counterfeit or remarked legacy parts. For fleets of deployed equipment, keeping qualified stock of this MCU extends service life by years at a component cost of only a few dollars per unit.
Recommended
Low-Cost Embedded Prototyping and Education
Universities and training labs that maintain legacy course material based on the Freescale HC08 architecture continue to use the MC908JB8FBE for teaching 8-bit embedded fundamentals. The M68HC08 instruction set demonstrates core concepts such as memory-mapped I/O, interrupt service routines, and timer control without the complexity of modern 32-bit toolchains, and 8KB FLASH is large enough for meaningful projects yet small enough to teach memory budgeting. The 44-QFP package can be soldered to adapter boards for breadboard use, and the 5V supply works with classic lab benchtop supplies and legacy peripheral chips. Its low unit cost allows students to keep and reuse development hardware across a semester.
Recommended
Battery-Powered and Handheld Accessories
The HC08JB family's low-power design philosophy suits battery-operated accessories such as remote controls, toy controllers, and handheld meters. The 3 MHz HC08 core delivers adequate performance with modest current consumption, and the family's power-management features allow sleep modes that extend battery life in duty-cycled products. The 8KB FLASH memory holds application logic plus power-state management code, and field reprogrammability lets manufacturers refine power profiles after launch. The 44-QFP (10 x 10 mm) footprint suits compact two-layer consumer PCBs, and the surface-mount format supports automated assembly. Where USB charging or USB data reporting is part of the accessory, the JB family's USB heritage provides a proven firmware baseline.
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Recommended Products Summary
Engineering reference data for MC908JB8FBE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68HC908JB8FBE |
|---|---|---|
| Package | 44-QFP (10 x 10 mm) | 44-QFP (10 x 10 mm) - same |
| Brand | NXP Semiconductors (Freescale) | NXP Semiconductors (Freescale) |
| Core | HC08 (8-bit CISC) | HC08 (8-bit CISC) |
| Max Clock Frequency | 3 MHz | 3 MHz |
| Program Memory Size | 8KB FLASH | 8KB ROM |
| Field Reprogrammable | Yes (FLASH) | No (mask ROM) |
| Supply Voltage | 5 V | 5 V |
| Lifecycle Status | Obsolete (aftermarket stock) | Obsolete (aftermarket stock) |
Key Differentiators
- FLASH program memory enables field and production reprogramming (vs MC68HC908JB8FBE)
- True pin-to-pin same-family compatibility (vs MC68HC908JB8FBE)
- Honest trade-off: both devices are obsolete (vs MC68HC908JB8FBE)
Design Notes
The MC908JB8FBE is a 5V device; provide a regulated 5V rail with 100 nF decoupling capacitors placed at each VDD pin pair of the 44-QFP package, plus one bulk capacitor near the supply entry. If the upstream rail is 3.3V or a USB bus supply with drop, verify the regulator maintains the MCU's minimum supply across load and temperature. Do not attempt to run the part at 3.3V based on modern-MCU habits; the HC08JB family was characterized at 5V, and undervoltage operation risks erratic oscillator behavior and FLASH programming failures.
Sourcing is the dominant risk: the part is discontinued, so marketplaces and brokers may offer remarked or recovered parts. Verify date codes against the original marking format, prefer franchised-distributor marketplace listings (e.g., Rochester Electronics via DigiKey Marketplace), and require certificates of conformance for production lots. Buy a buffer stock sized to remaining product lifetime, since FLASH-programmed replacements can be pre-programmed and stored. Also confirm that your programmer still supports the HC08 monitor/FLASH programming interface before committing to the substitution.
For legacy boards, the 44-QFP (10 x 10 mm) footprint must match the original land pattern including the lead pitch; verify the new supplier's reel or tray marking matches the exact suffix FBE before assembly, as other suffixes in the JB8 family may differ in package or memory type. For new adapter-based prototyping, use a 0.8 mm-pitch QFP-44 socket or solder the device to a DIP adapter and add a crystal plus reset pull-up per the family datasheet reference circuit.
Compliance Information
RoHS status listed as 'Details' without explicit value in distributor data; legacy device may have non-compliant date codes. Request compliance certificates from the seller.
