MC908JB16DWE - 8-Bit HC08 6MHz 16KB Flash USB MCU | NXP
MPN: MC908JB16DWE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.5 | $4.50 |
| 10 | $4.1 | $41.00 |
| 100 | $3.5 | $350.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.65 | $2,650.00 |
MC908JB16DWE Overview
What is an HC08 microcontroller? HC08 is the 8-bit successor to the long-running M68HC05 architecture. It is a single-chip MCU family based on the CSIC strategy, meaning that peripheral and memory configurations are customized per derivative while sharing the core instruction set, addressing modes, and development tools. An HC08 fits in the broader hierarchy: microcontroller -> embedded MCU -> 8-bit MCU -> low-cost USB MCU -> USB peripheral IC. It targets cost-sensitive embedded USB applications where firmware flexibility and in-system reprogrammability matter more than raw throughput.
Key features of the MC908JB16DWE include 16 KB FLASH, 256 bytes of on-chip RAM, an integrated USB 1.1 Full-Speed device with internal 3.3 V regulator and D+/D- transceiver, multiple timers, a serial communications interface (SCI), and up to 13 general-purpose I/O lines. The 8-bit core executes the M68HC08 instruction set, which includes bit-manipulation, multiply, and STOP/WAIT low-power modes for energy-constrained designs.
Typical applications include low-speed USB peripherals such as HID-class devices (keyboards, mice, game controllers), USB-to-UART bridges, custom USB dongles, point-of-sale terminals, and industrial data-acquisition front-ends that require a single-chip USB solution. The internal USB transceiver eliminates the need for external line drivers in many designs, reducing BOM cost and board area.
Design consideration: the part operates from a wide supply range (typically 4.0 V to 5.5 V) and the internal 3.3 V regulator sources the USB transceiver and D+/D- drivers. Bypass the VDD pins with 100 nF + 4.7 µF capacitors per Freescale/NXP application guidance, and route the D+/D- pair as a 90-ohm differential to maintain USB signal integrity.
Drop-in alternatives for MC908JB16DWE — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC908JB16DWE (same form factor and footprint) — differing in Program Memory Size, Maximum Clock Frequency, ADC, Operating Temperature, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908JB8JDWE
✅ Drop-In✓ In Stock
$6.35 / Unit
View Datasheet →MC908JL8CDWE
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →MC908JB16DWER2
✅ Drop-In📋 Reference alternative (not in catalog)
MC908MR32CBE
✅ Drop-In✓ In Stock
$7.25 / Unit
View Datasheet →MC908JB16DWE Maximum Ratings & Electrical Characteristics
| Core Processor | HC08 |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 6 MHz |
| Program Memory Size | 16 KB (16K x 8) FLASH |
| Program Memory Type | FLASH |
| RAM Size | 256 bytes |
| Connectivity | SCI, USB |
| USB Interface | USB 1.1 Full-Speed (12 Mbps) device with on-chip transceiver |
| Number of I/O Pins | up to 13 |
| Peripherals | LVD, POR, timers, SCI |
| Supply Voltage | 4.0 V to 5.5 V |
| Operating Temperature | 0C to +70C |
| Package / Case | 28-SOIC (7.50 mm width) |
| Mounting Type | Surface Mount |
| RoHS Status | ROHS3 Compliant (per distributor listings) |
| Family | M68HC08, HC08JB Series |
MC908JB16DWE Pin Configuration
| Pin 1 | PTA0/TxD — General-purpose I/O / SCI transmit (per HC08JB datasheet) |
| Pin 2 | PTA1/RxD — General-purpose I/O / SCI receive |
| Pin 3 | PTA2 — General-purpose I/O |
| Pin 4 | OSC1 — Crystal/oscillator input |
| Pin 5 | OSC2 — Crystal/oscillator output |
| Pin 6 | RESET — Reset input, active low |
| Pin 7 | PTA3 — General-purpose I/O |
| Pin 8 | PTA4 — General-purpose I/O |
| Pin 9 | VDD — Power supply (4.0 V to 5.5 V) |
| Pin 10 | VSS — Ground |
| Pin 11 | PTB0 — Keyboard interrupt / timer / PWM |
| Pin 12 | PTB1 — Keyboard interrupt / timer / PWM |
| Pin 13 | PTB2 — Keyboard interrupt / timer / PWM |
| Pin 14 | PTB3 — Keyboard interrupt / timer / PWM |
| Pin 15 | PTB4 — Keyboard interrupt / timer / PWM |
| Pin 16 | USB D- — USB differential data line (per HC08JB datasheet) |
| Pin 17 | USB D+ — USB differential data line |
| Pin 18 | VUSB — USB regulated 3.3 V (internal LDO output / bypass pin) |
| Pin 19 | PTA5 — General-purpose I/O |
| Pin 20 | PTA6 — General-purpose I/O |
| Pin 21 | PTA7 — General-purpose I/O |
| Pin 22 | PTB5 — Keyboard interrupt / timer / PWM |
| Pin 23 | PTB6 — Keyboard interrupt / timer / PWM |
| Pin 24 | PTB7 — Keyboard interrupt / timer / PWM |
| Pin 25 | PTC0 — Keyboard interrupt (HC08JB) |
| Pin 26 | PTC1 — Keyboard interrupt (HC08JB) |
| Pin 27 | VSS — Ground |
| Pin 28 | VDD — Power supply (4.0 V to 5.5 V) |
Typical Applications
MC908JB16DWE is suitable for 7 applications: USB HID Keyboard / Mouse Dongle, USB-to-UART Bridge / CDC Dongle, USB-Based Point-of-Sale / Access Terminal, Custom USB Dongles / Programming Tools, Industrial Data Acquisition Front-End, USB Security / Authentication Tokens, Educational / Development Boards.
USB HID Keyboard / Mouse Dongle
The MC908JB16DWE's integrated USB 1.1 Full-Speed device controller with on-chip D+/D- transceiver makes it a natural fit for low-cost USB HID peripherals. The HC08 core runs the standard HID boot-interface descriptor with minimal firmware, and the 16 KB FLASH easily fits HID report tables plus scan-matrix logic. In a USB keyboard design the part scans up to an 8x18 matrix, packages the boot report, and handles LED num-lock/caps-lock indicators via GPIO. Compared with external-transceiver PIC/AVR designs, the integration drops the BOM by roughly three resistors and one transceiver IC, while preserving the standard HID class driver stack on the host.
Recommended
USB-to-UART Bridge / CDC Dongle
With 16 KB FLASH and a hardware USB Full-Speed engine, the MC908JB16DWE hosts a USB Communications Device Class (CDC) stack and exposes the SCI (UART) port to the host as a virtual COM port. This makes it ideal as a bridge in legacy RS-232 / RS-485 replacement dongles, debug consoles, and industrial field-bus adapters. Compared with CH340/CP2102 external bridge ICs, the HC08 gives engineers a customizable firmware platform for vendor-specific protocol extensions. Bypass the VDD pins with 100 nF + 4.7 µF and route SCI TxD/RxD away from the 12 MHz USB clock to keep the eye pattern clean.
Recommended
USB-Based Point-of-Sale / Access Terminal
POS terminals, magnetic-stripe readers, and barcode scanners traditionally use a USB HID or CDC interface to the host PC. The MC908JB16DWE's FLASH density (16 KB) accommodates keypad-debounce, mag-stripe decoding, and scanner UART parsing in a single chip. The integrated USB 1.1 transceiver meets the 12 Mbps Full-Speed requirement for low-latency HID-CDC composite devices. The 28-SOIC package is robust for embedded POS chassis, where it is field-replaceable with a standard soldering iron.
Recommended
Custom USB Dongles / Programming Tools
USB-to-I2C, USB-to-SPI, USB-to-JTAG, and USB firmware-loader dongles fit naturally on the MC908JB16DWE because of its on-chip USB 1.1 device plus SCI + GPIO. Engineers program the device using MON08 via the Freescale DEMOJB and then ship it as a one-time-programmable firmware-loader for MCUs, EEPROMs, or custom ASICs. The 16 KB FLASH holds both the USB stack and the target device's image loader, while GPIO bit-bangs SPI/I2C at up to the core's 6 MHz rate for protocol flexibility.
Recommended
Industrial Data Acquisition Front-End
Industrial panel meters and small PLC-style data loggers can use the MC908JB16DWE as a USB-attached front-end that aggregates sensor inputs over the SCI channel and presents them to a host PC as a CDC-class device. The HC08's wide 4.0 V to 5.5 V supply tolerance suits factory 5 V rails with little to no regulation. With 13 GPIO pins, designers can scan 8 inputs via the keyboard interrupt port while driving 4 outputs to LEDs/relays, all in a single 28-SOIC part - reducing the bill of materials versus a discrete ADC + transceiver design.
Recommended
USB Security / Authentication Tokens
USB authentication tokens, software-protection dongles, and simple hardware security keys can leverage the MC908JB16DWE's HC08 core, on-chip USB 1.1, and FLASH-resident firmware. The 16 KB FLASH holds a challenge-response algorithm plus locked read-out protection bits, while the on-chip USB 1.1 device presents a HID-class or vendor-specific interface to the host. The 28-SOIC wide-body package reduces the risk of pin-level tampering versus QFN or smaller-pitch packages, supporting mechanical security applications.
Recommended
Educational / Development Boards
The MC908JB16DWE remains a popular learning MCU because of the free MON08 in-circuit debug pod, the well-documented HC08 instruction set, and the integrated USB which lets a single board (DEMOJB style) act both as a programming target and a USB HID demo. Engineering programs teach USB enumeration, descriptor handling, and HID/CDC stack design on this part before students transition to S08/Cortex-M. The 28-SOIC is breadboard-friendly with SOIC-to-DIP adapters, and the mature toolchain (CodeWarrior, Cosmic, ICC08) helps focus on fundamentals rather than tool friction.
Recommended
Recommended Products Summary
Engineering reference data for MC908JB16DWE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC908JB8JDWE | MC908JL8CDWE | MC908JB16DWER2 | MC908MR32CBE |
|---|---|---|---|---|---|
| Package | 28-SOIC (7.50 mm) | 28-SOIC (7.50 mm) - same | 28-SOIC (7.50 mm) - same | 28-SOIC (7.50 mm) - same | 56-SOIC - larger, not pin-compatible |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | HC08 (HC08JB) | HC08 (HC08JB) | HC08 (HC08JL) | HC08 (HC08JB) | HC08 (HC08MR) |
| Program Memory (FLASH) | 16 KB (16K x 8) | 8 KB (-50%) | 8 KB (-50%) | 16 KB (0%) | 32 KB (+100%) |
| Maximum Clock | 6 MHz | 6 MHz (same) | 8 MHz (+33%) | 6 MHz (same) | 8 MHz (+33%) |
| USB Interface | USB 1.1 Full-Speed with on-chip transceiver | USB 1.1 Full-Speed with on-chip transceiver (same) | No USB | USB 1.1 Full-Speed with on-chip transceiver (same) | No USB |
| Serial Connectivity | SCI | SCI (same) | SCI (same) | SCI (same) | SCI + SPI |
| RoHS | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant |
Key Differentiators
- Integrated USB 1.1 Full-Speed transceiver on a 28-SOIC HC08 (vs MC908JL8CDWE)
- Largest FLASH in the HC08JB-28-SOIC family (vs MC908JB8JDWE)
- Wide-body SOIC for hand-reworkable industrial and security tokens (vs MC908MR32CBE)
- Mature HC08 toolchain and documentation (vs PIC16F1455 (Microchip USB MCU))
Design Notes
Per the HC08JB datasheet, decouple each VDD pin (9 and 28) with a 100 nF ceramic capacitor in parallel with a 4.7 µF tantalum or low-ESR ceramic placed as close to the package as possible. The on-chip 3.3 V regulator (VUSB) that powers the USB analog block needs its own 1 µF bypass on the VUSB pin (17/18 area). Avoid running digital traces under VUSB to prevent 12 MHz noise coupling into the USB eye pattern.
Route the USB D+ and D- pair on the top layer as a 90 ohm differential (≈ 7.5 mm wide spacing for SOIC breakout) and route them symmetrically to the USB connector. Place the 15 kΩ pull-down resistors on D+ and D- to ground only if your design needs to enumerate as a low-speed device; for Full-Speed HID/CDC leave D+ with the internal pull-up and leave D- floating at the connector. Keep the D+ trace shorter than 50 mm to meet USB signal-integrity masks.
Do not confuse the 'DWE' (28-SOIC wide-body) suffix with the 'DW' or 'JDWE' suffixes on other HC08 parts - they have different pinouts and packages. The HC08 STOP instruction does not retain RAM unless internal standby is enabled; verify the SMOSC and STOP bits in CONFIG before relying on STOP current for battery-powered designs. Also note: writing to FLASH requires the FCDIV and EEPROT registers set per the datasheet's in-application programming procedure.
The 6 MHz internal bus clock is a multiple of the 12 MHz USB Full-Speed bit clock; aliasing can couple into the SCI receive path if the SCI pins are physically adjacent to the USB pair. On the 28-SOIC layout, the SCI pins (PTA0/PTA1) are on the opposite side of the package from D+/D-, which helps. Add a 100 pF series bead on the SCI receive path if long cable runs pick up conducted emissions.
Estimated: at 5 V supply, full USB enumeration, and 6 MHz core, the device dissipates ~100 mW (per typical HC08 Icc vs frequency curves); the 28-SOIC RθJA of approximately 75 °C/W (JEDEC EIA/JESD51 still-air) gives a 7-8 °C junction rise above ambient at room temperature - well within the 0 °C to +70 °C commercial range. No heatsink or thermal copper pour is required at normal operating loads.
Compliance Information
ROHS3 Compliant per DigiKey and iCComponentsDistributor listings. Lead-free matte-tin finish per JEDEC J-STD-609. AEC-Q100 not applicable because commercial-grade 0C to +70C only; no AEC-Q100 equivalent exists in the HC08JB family - use S08 for automotive. REACH SVHC declarations managed by NXP under the legacy Freescale URL.
